信濃 卓郎 (シナノ タクロウ)

農学研究院 基盤研究部門 生物機能化学分野教授
高等教育推進機構教授
Last Updated :2025/02/15

■研究者基本情報

学位

  • 農学修士, 北海道大学
  • 農学博士, 北海道大学

プロフィール情報

  • 現在は北海道にて作物栄養学の研究室に所属しております。

    同時に福島での農業現場における放射性物質対策に継続して取り組んでいます。

    研究業績

    ResearchGate: https://www.researchgate.net/profile/Takuro_Shinano

    Google Scholar: https://scholar.google.co.jp/citations?hl=ja&user=0137dF8AAAAJ

Researchmap個人ページ

研究キーワード

  • 移行低減
  • 放射性セシウム
  • 根圏
  • 必須元素
  • メタボローム
  • メタゲノム
  • イオノーム
  • 土壌微生物
  • ICP-MS
  • 根分泌物
  • 一酸化二窒素
  • GC-MS
  • UPLC-MS
  • 植物栄養学
  • 光合成能
  • 初期光合成産物
  • 網羅的無機分析
  • イオノミクス
  • 有害元素
  • 土壌RNA
  • 高等植物
  • 一次代謝産物
  • 有害金属
  • 植物系統樹
  • イネ科
  • LC-MS
  • 病害土壌
  • 植物生理
  • 根圏微生物
  • 作物栄養
  • Plant Nutrition

研究分野

  • 環境・農学, ランドスケープ科学
  • 環境・農学, 環境農学
  • 環境・農学, 農業環境工学、農業情報工学
  • ライフサイエンス, 植物栄養学、土壌学

担当教育組織

■経歴

経歴

  • 2019年04月 - 現在
    北海道大学, 農学研究院, 教授
  • 2013年04月 - 2019年03月
    国立研究開発法人農業・食品産業技術総合研究機構, 東北農業研究センター 農業放射線研究センター, センター長
  • 2008年04月 - 2013年03月
    独立行政法人農業・食品産業技術総合研究機構, 北海道農業研究センター, グループ長
  • 2003年12月 - 2008年03月
    -北海道大学創成科学共同研究機構, 流動研究部門, 准教授
  • 2002年04月 - 2008年03月
    -北海道大学大学院農学研究科助教授
  • 2002年06月 - 2002年08月
    ドイツ マーティン・ルター大学研究員
  • 1990年12月 - 2002年03月
    北海道大学農学部助手, Faculty of Agriculture
  • 2001年11月 - 2002年01月
    ブラジル サンパウロ大学研究員

学歴

  • 1988年, 北海道大学, 農学研究科, 農芸化学, 日本国
  • 1988年, 北海道大学, Graduate School, Division of Agriculture
  • 1986年, 北海道大学, 農学部, 生物機能化学, 日本国
  • 1986年, 北海道大学, Faculty of Agriculture

委員歴

  • 2023年10月 - 現在
    日本学術会議, 連携会員, 学協会
  • 2023年05月 - 現在
    日本土壌肥料学会, 副会長, 学協会
  • 2022年09月 - 現在
    International Union of Soil Science, Division 4.2 vice chair, その他
  • 2021年12月 - 現在
    除去土壌の再生利用に係る植物栽培試験検討会, 委員, その他
  • 2019年05月 - 現在
    放射能環境動態・影響評価ネットワーク共同拠点, 評価委員, 学協会
  • 2019年05月 - 現在
    飯舘村長泥地区環境再生事業運営協議会, 飯舘村長泥地区環境再生事業運営協議会委員, 自治体
  • 2017年04月 - 現在
    放射性物質環境移行低減化調査検討委員会, 自治体
  • 2016年04月 - 現在
    日本土壌肥料学会, 代議員, 学協会
  • 2022年04月 - 2023年09月
    日本土壌肥料学会, 第4部門部門長, 学協会
  • 2021年05月 - 2023年09月
    日本学術会議, 土壌科学分科会特任連携会員, 学協会
  • 2020年04月 - 2023年03月
    専門高校NEXT人材育成協議会, 委員, 自治体
  • 2022年04月 - 2022年09月
    日本土壌肥料学会, 欧文誌編集委員会編集委員, 学協会
  • 2020年04月 - 2022年03月
    日本土壌肥料学会, 欧文誌編集委員会副委員長, 学協会
  • 2020年02月 - 2022年03月
    大学改革支援・学位授与機構, 国立大学教育研究評価委員会専門委員, 学協会
  • 2019年04月 - 2020年03月
    日本土壌肥料学会, 第4部門部門長, 学協会
  • 2016年 - 2019年03月
    福島県科学技術調整会議, 外部評価アドバイザー, 自治体
  • 2015年04月 - 2019年03月
    日本土壌肥料学会, 第8部門副部門長, 学協会
  • 2016年 - 2017年
    日本土壌微生物学会, 評議員, 学協会
  • 2004年 - 2015年
    植物微生物研究会, 世話人, 学協会
  • 2002年 - 2014年
    日本熱帯生熊学会, 編集幹事, 学協会
  • 2004年 - 2006年
    日本土壌肥料学会, 部門委員, 学協会
  • 2002年 - 2003年
    Society of Soil Science and Plant Nutrition, General Affairs of Hokkaido Branch, 学協会
  • 2002年
    Hokkaido Dojyo Hiryo Konwakai, Committee, 学協会
  • 2001年
    The Society of Tropical Agriculture, Editorial Committee, 学協会

■研究活動情報

受賞

  • 2022年09月, 日本土壌肥料学会, 若手口頭発表優秀賞               
    土壌‐作物系への岩石散布に伴う風化促進による炭素隔離および作物生育の Co-benefit の検証
    東和喜・中尾淳・信濃卓郎・万福裕造・久保堅司・丸山隼人・佐藤孝・矢内純太
  • 2022年09月, 日本土壌肥料学会, 若手ポスター発表優秀賞               
    ミナトカモジグサ菌根共生系にお けるリン獲得の菌種特徴的分子機構
    永山航平・菅井徹人・ 佐藤匠・神山拓也・ 市橋泰範・渡部敏裕・ 信濃卓郎・丸山隼人
  • 2019年03月, 日本作物学会, 日本作物学会論文賞               
    Effect of soil exchangeable potassium content on cesium absorption and partitioning in buckwheat grown in a radioactive cesium-contaminated field.
    久保堅司;藤村恵人;小林浩幸;太田健;信濃卓郎
  • 2018年05月, 日本土壌肥料学会, 学会賞               
    信濃 卓郎
  • 2016年10月, NARO Special Prize II               
    加藤 直人, 信濃 卓郎, 太田 健, 久保 堅司, 内田 智子, 松波 寿弥, 江口 哲也, 島田 信二, 小林 浩幸, 関口 哲生, 栂村 恭子, 山田 大吾, 渋谷 岳 , 木方 展治, 山口 紀子, 原田 久富美, 渡邊 好昭, 伊藤 純雄, 木村 武
  • 2013年09月, 日本土壌肥料学会, 優秀ポスター賞               
    ダイズ根系が根圏土壌へ分泌した有機物の可視化と定量解析
    尹 永根, 鈴井 伸郎, 河地 有木, 石井 里美,小柳 淳, 信濃 卓郎, 藤巻 秀
  • 2013年06月, 日本土壌微生物学会, 最優秀ポスター賞               
    ジャガイモ根関連細菌の培養解析
    染谷 信孝, 海野 佑介, 信濃 卓郎, 津田 昌吾, 池田 成志, 関口 博之
  • 2008年05月, 日本土壌肥料学会, ポスター賞               
    アブラナ科植物に対する堆肥施用効果の代謝産物および遺伝子発現プロファイリング
    岡崎 圭毅, 信濃 卓郎, 岡 紀邦, 和崎 淳, 中村 卓司, 大崎 満, 建部 雅子
  • 2000年, 土壤肥料学会奨励賞               
    日本国
  • 2000年, The Progress Award, Japanese Society of Soil Science and Plant Nutrition               

論文

  • Impact of basalt application on soil chemical properties and elemental uptake by paddy rice through enhanced rock weathering
    Hiroshi Uchibayashi, Hayato Maruyama, Toshihiro Watanabe, Shoichiro Hamamoto, Yo Toma, Atsushi Nakao, Kohei Kurokawa, Takuro Shinano
    Soil Science and Plant Nutrition, 2025年01月07日
    研究論文(学術雑誌)
  • Examination of the reliability of X‐ray powder diffraction analysis to determine mineral composition of soils
    Kohei Kurokawa, Kazuki Azuma, Atsushi Nakao, Atsuhito Suzuki, Shokichi Wakabayashi, Shigeto Fujimura, Takuro Shinano, Junta Yanai
    Soil Science Society of America Journal, Wiley, 2024年09月12日
    研究論文(学術雑誌), Abstract

    X‐ray powder diffraction (XRPD) is an effective technique for identifying and quantifying mineral types in soil. However, few studies have compared quantitative values based on XRPD with those from conventional wet chemical methods (WCMs). Here, we determined the primary mineral content in artificial mineral mixtures and 79 agricultural soils from across Japan using WCMs and two XRPD‐based quantitative methods: the mineral intensity factor (MIF) and the full‐pattern summation (FPS) methods performed with the powdR package for R. For artificial mixtures, the accuracy of mineral content determination (i.e., micas, quartz, K‐feldspar, and plagioclase) followed the order: WCMs > FPS > MIF. For Japanese agricultural soils, the contents of each mineral were highly similar between WCMs and FPS, based on mean absolute differences and correlation coefficients. Alternatively, MIF displayed lower similarities with WCMs, likely due to preferred orientation and peak shift or overlap issues. Using the FPS method, the mica and amorphous phase contents were positively and significantly correlated with nonexchangeable K content and cation exchange capacity, respectively. Additionally, the plagioclase content was negatively and significantly correlated with clay content. Thus, the powdR‐based FPS method is recommended for determining the mineral composition of soils, as it allows for a clearer and more quantitative demonstration of the relationship between individual minerals and soil properties.
  • 8-2-2 畑地への玄武岩施与が土壌化学性およびダイズの生育に及ぼす影響と風化促進の可能性(8-2 地球環境 2024年度福岡大会)
    内林 大志, 丸山 隼人, 渡部 敏裕, 当真 要, 濱本 昌一郎, 楊 椅麟, 朱 顔, 小坂 弦, 中尾 淳, 黒川 耕平, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 70, 152, 152, 一般社団法人 日本土壌肥料学会, 2024年08月26日
    日本語
  • 2-1-19 粉末X線回折法を用いた土壌鉱物定量法の新提案-モンスーンアジアにおいて易風化性鉱物に富む日本の土壌に着目して-(2-1 土壌有機・無機成分の構造・機能・ダイナミクス 2024年度福岡大会)
    黒川 耕平, 中尾 淳, 鈴木 篤人, 東 和喜, 田中 壮太, 若林 正吉, 藤村 恵人, 信濃 卓郎, 矢内 純太
    日本土壌肥料学会講演要旨集, 70, 18, 18, 一般社団法人 日本土壌肥料学会, 2024年08月26日
    日本語
  • P8-2-3 ダイズ栽培システムへの玄武岩施用が養分動態および鉱物風化量に及ぼす影響の土壌間差(8-2 地球環境 2024年度福岡大会)
    堀 百合菜, 中尾 淳, 黒川 耕平, 信濃 卓郎, 丸山 隼人, 岩崎 真也, 内林 大志, 矢内 純太
    日本土壌肥料学会講演要旨集, 70, 156, 156, 一般社団法人 日本土壌肥料学会, 2024年08月26日
    日本語
  • 6-1-4 日本広域水田土壌を用いたMehlich3法による可給態元素と鉱物組成の網羅的関連解析(6-1 水田土壌肥沃度 2024年度福岡大会)
    池田 未来, 中尾 淳, 黒川 耕平, 信濃 卓郎, 藤村 恵人, 矢内 純太
    日本土壌肥料学会講演要旨集, 70, 92, 92, 一般社団法人 日本土壌肥料学会, 2024年08月26日
    日本語
  • Effects of cattle manure compost application on crop growth and soil-to-crop transfer of cesium in a physically radionuclide-decontaminated field
    Masataka Suzuki, Katashi Kubo, Mayumi Hachinohe, Takashi Sato, Hirofumi Tsukada, Noriko Yamaguchi, Toshihiro Watanabe, Hayato Maruyama, Takuro Shinano
    Science of The Total Environment, 167939, 2023年11月, [査読有り]
  • Influence of fluorine content of potassium trioctahedral micas on plant availability of interlayer potassium and effectiveness to reduce radiocesium uptake by paddy rice
    Tetsuya Eguchi, Hisaya Matsunami, Shigeto Fujimura, Takuro Shinano
    Applied Clay Science, 243, 107049, 107049, Elsevier BV, 2023年10月, [査読有り]
    研究論文(学術雑誌)
  • 1 定植栽培による緑肥作物すき込み後の作付の早期化の可能性(北海道支部講演会)
    内林 大志, 平田 聡之, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 69, 213, 213, 一般社団法人 日本土壌肥料学会, 2023年09月04日
    日本語
  • 1. 「オミックス科学」×「土壌肥料学」の新展開
    西田 翔, 信濃 卓郎
    日本土壌肥料学雑誌, 94, 3, 208, 209, 一般社団法人 日本土壌肥料学会, 2023年06月05日
    日本語
  • Potassium applications reduced cesium uptake and altered strontium translocation in soybean plants
    Muhamad Syaifudin, Masataka Suzuki, Hayato Maruyama, Katashi Kubo, Toshihiro Watanabe, Takuro Shinano
    Soil Science and Plant Nutrition, 2023年03月04日, [査読有り]
    研究論文(学術雑誌)
  • Reduction of Radiocesium in Internal- and Surface-Contaminated Komatsuna (Brassica rapa var. perviridis) during Washing and Processing
    Mayumi Hachinohe, Hideshi Fujiwara, Takuro Shinano, Hayato Maruyama, Katashi Kubo, Takashi Saito
    Journal of Food Protection, 86, 3, 100060, 100060, Elsevier BV, 2023年03月, [査読有り]
    研究論文(学術雑誌)
  • Potassium buffering characteristics and detection of soils with challenges in evaluating radiocesium uptake risk of crops by exchangeable potassium
    Tetsuya Eguchi, Daigo Yamada, Takashi Hirayama, Kazuhiro Kohata, Noboru Kanno, Naoto Nihei, Shoichiro Hamamoto, Katashi Kubo, Takashi Saito, Takuro Shinano
    ARCHIVES OF AGRONOMY AND SOIL SCIENCE, TAYLOR & FRANCIS LTD, 2023年02月, [査読有り]
    英語, 研究論文(学術雑誌), In surrounding areas influenced by the Fukushima Dai-ichi Nuclear Power Plant accident, the radiocesium uptake by crops was evaluated based on soil exchangeable K. As risk evaluation does not function effectively in several fields, K buffering was characterized using quantity/intensity (Q/I) relationship analysis to evaluate the availability of exchangeable K. The results of the analysis clearly explain the difficulty in the risk evaluation: i) difficulty in increasing exchangeable K, owing to retention as non-exchangeable K by vermiculite; ii) difficulty in retaining exchangeable K due to low K buffering capacity, reflecting the lack of K-selective clay minerals; and iii) difficulty in increasing soil solution K intensity due to high K buffering capacity, reflecting the abundance of K-selective clay minerals. Among the parameters calculated from the Q/I relationship analysis, beta values, corresponding to the retention rate of loaded K to the soil, for total K (beta t), exchangeable K (beta e), and non-exchangeable K (beta n) would be useful as simple indicators of soils with a predicament in the risk evaluation of radiocesium uptake by crops through exchangeable K. These soils showed distinctively low beta t values (0.18 or lower), high beta e value (0.37 or higher), or high beta n/beta t ratio (0.53 or higher).
  • Different nitrogen acquirement and utilization strategies might determine the ecological competition between ferns and angiosperms
    Chengming Zhang, Chaoqun Zhang, Takayuki Azuma, Hayato Maruyama, Takuro Shinano, Toshihiro Watanabe
    Annals of Botany, Oxford University Press (OUP), 2023年01月20日, [査読有り]
    研究論文(学術雑誌), Abstract

    Background and Aims

    The abundance or decline of fern populations in response to environmental change has been found to be largely dependent on specific physiological properties that distinguish ferns from angiosperms. Many studies have focused on water use efficiency and stomatal behaviours, but the effects of nutrition acquirement and utilization strategies on niche competition between ferns and flowering plants are rarely reported.

    Methods

    We collected 34 ferns and 42 angiosperms from the Botanic Garden of Hokkaido University for nitrogen (N), sulphur (S), NO3− and SO42− analysis. We then used a hydroponic system to compare the different N and S utilization strategies between ferns and angiosperms under N deficiency conditions.

    Key Results

    Ferns had a significantly higher NO3−-N concentration and NO3−-N/N ratio than angiosperms, although the total N concentration in ferns was remarkably lower than that in the angiosperms. Meanwhile, a positive correlation between N and S was found, indicating that nutrient concentration is involved in assimilation. Pteris cretica, a fern species subjected to further study, maintained a slow growth rate and lower N requirement in response to low N stress, while both the biomass and N concentration in wheat (Triticum aestivum) responded quickly to N deficiency conditions.

    Conclusions

    The different nutritional strategies employed by ferns and angiosperms depended mainly on the effects of phylogenetic and evolutionary diversity. Ferns tend to adopt an opportunistic strategy of limiting growth rate to reduce N demand and store more pooled nitrate, whereas angiosperms probably utilize N nutrition to ensure as much development as possible under low N stress. Identifying the effects of mineral nutrition on the evolutionary results of ecological competition between plant species remains a challenge.
  • Detection of metabolites in rhizosphere of soybean under different status of soil potassium
    Firdausi Nur Azizah, Benito Heru Purwanto, Akira Oikawa, Takuro Shinano, Weiguo Cheng, Keitaro Tawaraya
    Soil Science and Plant Nutrition, 69, 2, 69, 77, TAYLOR & FRANCIS LTD, 2023年01月19日, [査読有り]
    英語, 研究論文(学術雑誌), Nutrient status of plant affects root exudates of plant. Little is known about effect of potassium status on root exudation. Objective of this study was to identify metabolites in rhizosphere soil of soybean under different potassium conditions. Two soybean cultivars (Satonohohoemi (SAT) and Tachinagaha (TAC)) were grown in soil culture under low (K0, without potassium fertilizer) and normal (K2, 0.42 g K kg(-1)) soil potassium status. Soil solutions were collected at 15 and 25 DAS. Metabolites in soil solution were detected by CE-TOF MS. Low potassium tolerance was higher in SAT than TAC. Shoot and root K concentration in SAT was lower in K0 than that in K2. Forty-seven metabolites were detected in rhizosphere soil solution of SAT, TAC and without plant. Low K condition increased 6 and 3 metabolites concentration in soil solution without plant and 2 and 4 metabolites concentration with SAT and 2 and 1 metabolites concentration with TAC, at 15 and 25 DAS, respectively. Low K condition decreased 1 and 1 metabolites concentration in soil solution without plant and 6 and 6 metabolites concentration with SAT and 0 and 2 metabolites concentration with TAC, at 15 and 25 DAS, respectively. Increased and decreased metabolites were different between SAT and TAC. These results suggest that K status affect metabolites in root exudate and rhizosphere microbes of soybean and there is cultivar difference in these metabolites.
  • Radioactive Cs transfer to vegetables after the FDNPP accident
    Takuro Shinano, Satoshi Asaeda, Saeko Yashiro, Takashi Saito, Hayato Maruyama, Tomoaki Nemoto, Mayumi Hachinohe
    Soil Science and Plant Nutrition, 2023年01月02日
    研究論文(学術雑誌)
  • The ratio of plant 137Cs to exchangeable 137Cs in soil is a crucial factor in explaining the variation in 137Cs transferability from soil to plant.
    Masataka Suzuki, Tetsuya Eguchi, Kazuki Azuma, Atsushi Nakao, Katashi Kubo, Shigeto Fujimura, Muhamad Syaifudin, Hayato Maruyama, Toshihiro Watanabe, Takuro Shinano
    The Science of the total environment, 857, Pt 1, 159208, 159208, 2022年10月05日, [査読有り], [最終著者, 責任著者], [国際誌]
    英語, 研究論文(学術雑誌), To mitigate radioactive cesium from soil to plant, increasing and maintaining the exchangeable potassium (ExK) level during growth is widely accepted after Tokyo Electric Company's Fukushima Dai-ichi Nuclear Plant accident in Japan. This is because the antagonistic relationship between soil solution K and 134Cs + 137Cs (RCs) concentrations changes the transfer factor (TF: designated as the ratio of radioactivity of plant organ to soil) of RCs. As the relationship between ExK and TF depends on the soil types, crop species, and other environmental factors, the required amount of ExK should be set to a safe side. Eleven years after the accident, as the activity of 134Cs was almost negligible, 137Cs became the main RCs in most of the agricultural fields in Fukushima Prefecture. We propose a new indicator, the concentration ratio of plant 137Cs to soil exchangeable 137Cs (Ex137Cs), instead of TF, which showed a better correlation with ExK even among soils with different properties (or mineralogy).
  • P4-3-9 アルミニウム集積植物メラストーマにおけるFRD3タイプMATE のアルミニウム輸送への関与(4-3 植物の有害元素 2022年度東京大会)
    坂口 文香, 丸山 隼人, 佐々木 孝行, 西田 翔, 和崎 淳, 信濃 卓郎, 渡部 敏裕
    日本土壌肥料学会講演要旨集, 68, 59, 59, 一般社団法人 日本土壌肥料学会, 2022年09月05日
    日本語
  • 4-4-4 パプリカ果実における部位別の元素動態と尻腐れ果発症との関係(4-4 植物の代謝成分と農作物の品質 2022年度東京大会)
    荒川 竜太, 鳥山 星呂, アクリッシュ 穂波, 渡部 敏裕, 信濃 卓郎, 丸山 隼人
    日本土壌肥料学会講演要旨集, 68, 62, 62, 一般社団法人 日本土壌肥料学会, 2022年09月05日
    日本語
  • Growth and nitrogen use characteristics of black locust, an invasive alien species, grown under different light and CO2 conditions
    Satoshi Kitaoka, Saki Fujita, Yoko Watanabe, DongSu Choi, Toshihiro Watanabe, Takuro Shinano, Fuyuki Satoh, Takayoshi Koike
    Eurasian Journal of Forests Research, 22, 28, 32, 2022年04月, [査読有り], [招待有り]
    英語, 研究論文(大学,研究機関等紀要)
  • Relationship between soil phosphorus dynamics and low-phosphorus responses at specific root locations of white lupine
    Ayane Kan, Hayato Maruyama, Nao Aoyama, Jun Wasaki, Yoshiko Tateishi, Toshihiro Watanabe, Takuro Shinano
    Soil Science and Plant Nutrition, 2022年, [査読有り], [最終著者]
    研究論文(学術雑誌), Phosphorus (P) is an essential element for crop production; however, availability tends to be low due to slow diffusion and high fixation in soils. To cope with phosphate deficiency, white lupines (Lupinus albus L.) form unique root structures called cluster roots. The objective of this study was to elucidate detailed spatial differences of the mechanisms under low-P condition in the root system using rhizoboxes. We cultivated plants in rhizoboxes with P-deficient soil for 33 days. We then harvested roots and the adjacent soil from 128 compartments by dividing 2 × 2 cm squares in the rhizoboxes. We investigated relative expression levels of several genes that encode proteins assumed to be involved in P solubilization or translocation. Additionally, we analyzed fractionated P, soluble metal cations (Fe, Al, and Mn), and enzyme activities in the soil of each compartment. We observed a significant positive correlation between one of the MATE (multidrug and toxic compound extrusion/detoxification) genes, LaMATE6, and soluble metal cations, suggesting the secretion of citric acid into the rhizosphere via MATE proteins increased soluble metal cation concentrations. Furthermore, we demonstrated that roots in the same developmental stages were likely to have different influences on the mobilization of fractionated P in the rhizosphere soil. Our findings highlight the importance of investigating the relationship between soil chemical properties and root functions at a high spatial resolution to elucidate the detailed mechanisms of P mobilization by plants.
  • Ionomic Profiling of Rice Genotypes and Identification of Varieties with Elemental Covariation Effects
    Zhang Chengming, Nobuhiro Tanaka, Maria Stefanie Dwiyanti, Matthew Shenton, Hayato Maruyama, Takuro Shinano, Chu Qingnan, Xie Jun, Toshihiro Watanabe
    Rice Science, 29, 1, 76, 88, Elsevier BV, 2022年01月, [査読有り]
    英語, 研究論文(学術雑誌), Ionomic profiles are primarily influenced by genetic and environmental factors. Identifying ionomic responses to varietal effects is necessary to understand the ionomic variations among species or subspecies and to potentially understand genetic effects on ionomic profiles. We cultivated 120 rice (Oryza sativa) varieties to seedling stage in identical hydroponic conditions and determined the concentrations of 26 elements (including 3 anions) in the shoots and roots of rice. Although the subspecies effects were limited by the genus Oryza pre-framework and its elemental chemical properties, we found significant differences in ionomic variations in most elements among the aus, indica and japonica subspecies. Principal component analysis of the correlations indicated that variations in the root-to-shoot ionomic transport mechanisms were the main causes of ionomic differences among the subspecies. Furthermore, the correlations were primarily associated with the screening of varieties for elemental covariation effects that can facilitate breeding biofortified rice varieties with safe concentrations of otherwise toxic elements. The japonica subspecies exhibited the strongest elemental correlations and elemental covariation effects, therefore, they showed greater advantages for biofortification than the indica and aus subspecies, whereas indica and aus subspecies were likely safer in metal(loid) polluted soils. We also found that geographical and historical distribution significantly defined the ionomic profiles. Overall, the results of this study provided a reference for further association studies to improve the nutritional status and minimize toxicity risks in rice production.
  • Nitrogen deficiency-induced molybdenum accumulation in wheat
    Toshihiro Watanabe, Ryoskuke Okada, Soyoka Tokunaga, Hayato Maruyama, Masaru Urayama, Takuro Shinano
    JOURNAL OF PLANT NUTRITION, 45, 9, 1413, 1424, TAYLOR & FRANCIS INC, 2021年12月, [査読有り], [最終著者]
    英語, 研究論文(学術雑誌), In the present study, we conducted experiments using wheat to elucidate whether the increased accumulation of molybdenum in leaves under nitrogen deficiency is due to the plant's own metabolic response, and further to estimate the role of molybdenum in the nitrogen deficiency response. Even under different growth conditions such as soil culture, hydroponic culture, and aseptic culture, the nitrogen deficiency always increased the molybdenum accumulation in leaves of wheat. Because molybdenum supply to the soil enhanced the growth of wheat under nitrogen deficiency but did not increase plant nitrogen concentration, the increased molybdenum uptake might be involved in the adaptive mechanisms to nitrogen deficiency by increasing nitrogen use efficiency. Wheat under nitrogen deficiency accumulated more molybdenum in lower leaves. Moreover, the nitrogen concentration of wheat grown under nitrogen deficiency increased in the lower leaves and decreased in the upper leaves with the application of molybdenum. These results suggest that molybdenum might affect nitrogen translocation from older to younger leaves.
  • Physiological Role of Aerobic Fermentation Constitutively Expressed in an Aluminum-Tolerant Cell Line of Tobacco (Nicotiana tabacum).
    Yoshiyuki Tsuchiya, Takuji Nakamura, Yohei Izumi, Keiki Okazaki, Takuro Shinano, Yasutaka Kubo, Maki Katsuhara, Takayuki Sasaki, Yoko Yamamoto
    Plant & cell physiology, 62, 9, 1460, 1477, 2021年11月17日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Aluminum (Al)-tolerant tobacco cell line ALT301 hardly exhibits Al-triggered reactive oxygen species (ROS) production, compared with wild-type line SL. Molecular mechanism leading to this phenotype was investigated comparatively with SL. Under normal growth condition, metabolome data suggested the activation of glycolysis and lactate fermentation but the repression of the tricarboxylic acid (TCA) cycle in ALT301, namely aerobic fermentation, which seemed to be transcriptionally controlled partly by higher expression of genes encoding lactate dehydrogenase and pyruvate dehydrogenase kinase. Microarray and gene ontology analyses revealed the upregulation of the gene encoding RELATED TO APETALA2.3 (RAP2.3)-like protein, one of the group VII ethylene response factors (ERFVIIs), in ALT301. ERFVII transcription factors are known to be key regulators for hypoxia response which promotes substrate-level ATP production by glycolysis and fermentation. ERFVIIs are degraded under normoxia by the N-end rule pathway of proteolysis depending on both oxygen and nitric oxide (NO), and NO is produced mainly by nitrate reductase (NR) in plants. In ALT301, levels of the NR gene expression (NIA2), NR activity, and NO production were all lower, compared with SL. Consistently, the known effects of NO on respiratory pathways were also repressed in ALT301. Under Al-treatment condition, NO level increased in both lines, but was lower in ALT301. These results suggest that the upregulation of the RAP2.3-like gene and the downregulation of the NIA2 gene and resultant NO depletion in ALT301 coordinately enhance aerobic fermentation, which seems to be related to a higher capacity to prevent ROS production in mitochondria under Al stress.
  • Erratum To: Physiological Role of Aerobic Fermentation Constitutively Expressed in an Aluminum-Tolerant Cell Line of Tobacco (Nicotiana Tabacum).
    Yoshiyuki Tsuchiya, Takuji Nakamura, Yohei Izumi, Keiki Okazaki, Takuro Shinano, Yasutaka Kubo, Maki Katsuhara, Takayuki Sasaki, Yoko Yamamoto
    Plant & cell physiology, 62, 6, 1058, 1058, 2021年10月11日, [国内誌]
    英語
  • Possible solubilization of various mineral elements in the rhizosphere of Lupinus albus L.
    Atsuhide Takao, Jun Wasaki, Hisae Fujimoto, Hayato Maruyama, Takuro Shinano, Toshihiro Watanabe
    Soil Science and Plant Nutrition, 1, 8, Informa UK Limited, 2021年10月07日, [査読有り]
    研究論文(学術雑誌)
  • Application of Finnish phlogopite to reduce radiocesium uptake by paddy rice.
    Tetsuya Eguchi, Tetsuya Ishikawa, Shigeto Fujimura, Takeshi Ota, Shokichi Wakabayashi, Hisaya Matsunami, Takuro Shinano
    Journal of environmental radioactivity, 237, 106687, 106687, 2021年10月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Field and pot experiments were conducted to evaluate the effectiveness of coarse Finnish phlogopite application to reduce radiocesium uptake by paddy rice (Oryza sativa L.). The application of phlogopite was expected to reduce radiocesium uptake by crops through K supply and radiocesium retention. Three fields were set in Fukushima Prefecture, and coarse (mean particle size of 450 μm) phlogopite from Siilinjärvi (Finland) was applied at a rate of 5 t ha-1. Paddy rice was cultivated for 2-4 successive years. In all fields, the average 137Cs transfer factor (TF) of brown rice harvested from plots with added phlogopite was significantly lower than that of brown rice from plots without added phlogopite over the 2-4-year experiments. TF was decreased by up to 80% following phlogopite application, without an adverse effect on yield. Exchangeable K and soil solution K were higher in the soils with added phlogopite, suggesting K released from phlogopite reduced 137Cs uptake by paddy rice. Moreover, in a pot cultivation experiment, even when 55% of the total K was removed from phlogopite prior to application, the TF in pots with phlogopite application was less than half of that in pots without added phlogopite. The results from the field study and the pot cultivation experiment suggested that the application of Finnish phlogopite is effective to reduce the TF of brown rice. Exchangeable K and tetraphenylborate-extractable-K (TPB-K) at rooting stage, and soil solution K at tillering and heading stages showed significant negative correlation with TF. TPB-K was significantly positively correlated with soil solution K at tillering stage and heading stage, whereas exchangeable K at rooting stage did not exhibit significant correlation with soil solution K at heading stage. The results suggest that TPB-K is more reliable than exchangeable K, which could facilitate as a basis of K fertilizer recommendation for radiocesium-contaminated fields.
  • 4-1-4 シロバナルーピン根域における土壌中リン動態に与える影響の局所的評価(4-1 植物の多量栄養素 2021年度北海道大会)
    菅 あやね, 丸山 隼人, 和崎 淳, 渡部 敏裕, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 67, 45, 45, 一般社団法人 日本土壌肥料学会, 2021年09月03日
    日本語
  • 8-1-11 異なる圃場におけるダイズへの放射性セシウムの移行比較(8-1 環境保全 2021年度北海道大会)
    鈴木 政崇, 藤本 久恵, 浅枝 諭史, 丸山 隼人, 久保 堅司, 藤村 恵人, 渡部 敏裕, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 67, 126, 126, 一般社団法人 日本土壌肥料学会, 2021年09月03日
    日本語
  • 8-1-10 シロバナルーピンの放射性セシウム吸収特性と根圏土壌中元素動態の関係(8-1 環境保全 2021年度北海道大会)
    浅枝 諭史, 丸山 隼人, 藤本 久恵, 久保 堅司, 藤村 恵人, 渡部 敏裕, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 67, 126, 126, 一般社団法人 日本土壌肥料学会, 2021年09月03日
    日本語
  • P4-1-19 トマト尻腐れ発症率の品種間差と果実への無機元素蓄積の関係(4-1 植物の多量栄養素 2021年度北海道大会)
    長谷川 公紀, 渡邊 涼太郎, 丸山 隼人, 金山 喜則, 信濃 卓郎, 渡部 敏裕
    日本土壌肥料学会講演要旨集, 67, 58, 58, 一般社団法人 日本土壌肥料学会, 2021年09月03日
    日本語
  • 4-1-5 異なる土壌における白花ルーピンの根分泌物分布特性の可視化(4-1 植物の多量栄養素 2021年度北海道大会)
    尹 永根, 鈴井 伸郎, 三好 悠太, 海野 佑介, 丸山 隼人, 和崎 淳, 菅 あやね, 圓尾 明子, 渡部 敏裕, 橋本 洋平, 内田 翔子, 信濃 卓郎, 河地 有木
    日本土壌肥料学会講演要旨集, 67, 45, 45, 一般社団法人 日本土壌肥料学会, 2021年09月03日
    日本語
  • Ionomic differences between tomato introgression line IL8-3 and its parent cultivar M82 with different trends to the incidence of blossom-end rot
    Toshihiro Watanabe, Ryota Tomizaki, Ryotaro Watanabe, Hayato Maruyama, Takuro Shinano, Masaru Urayama, Yoshinori Kanayama
    SCIENTIA HORTICULTURAE, 287, ELSEVIER, 2021年09月, [査読有り]
    英語, 研究論文(学術雑誌), Fruit blossom-end rot (BER) is a serious physiological disorder that can cause significant yield losses in tomato (Solanum lycopersicum). Although many studies have suggested that calcium (Ca) deficiency in tomato fruits is a major factor for BER, its onset mechanism has not been fully elucidated. Ionomics is a high-throughput elemental profiling of living organisms that can be applied to understand how differences in plant's physiological status involving inorganic elements. In this study, we examined ionomic differences between the tomato cultivar M82 and its introgression line IL8-3, which contains a short chromosome segment from its wild relative Solanum pennellii on chromosome 8 of M82, and has a low incidence of fruit BER. Among the essential elements, Ca showed marked different behavior between the two lines. IL8-3 showed preferential Ca partitioning to fruits compared with M82. The slow growth rate and high Ca concentration observed in IL8-3 fruit during the early growth stages may also be responsible for the low BER incidence in this line. Although Ca ions bind to cell wall pectin and membrane phospholipids, and contribute to cell structure stability, these components showed no significant differences between fruits of the two lines. The fruit ionome differed considerably between M82 and IL8-3, and was not affected by available Ca status in the field. The M82 fruit had higher concentrations of many elements such as magnesium, potassium, boron, and sulfur than did IL8-3, and this trend was also observed in rotten fruit. This suggests that the influence of the leaf (source), rather than the fruit (sink), could be involved in the onset mechanism of BER.
  • Comparative dynamics of potassium and radiocesium in soybean with different potassium application levels.
    Hisaya Matsunami, Tomoko Uchida, Hiroyuki Kobayashi, Takeshi Ota, Takuro Shinano
    Journal of environmental radioactivity, 233, 106609, 106609, 2021年07月, [査読有り], [最終著者], [国際誌]
    英語, 研究論文(学術雑誌), We conducted a field experiment in soybean with different levels of K application to elucidate the comparative dynamics of 137Cs and K. The inventory of K in the shoots increased substantially from the fifth trifoliate stage to the full seed stage, and as the absorption of K increased, so too did the absorption of 137Cs. Overall, the effect of K application was much greater in terms of 137Cs dynamics than K dynamics or biomass production. K application reduced not only the accumulation of 137Cs in the shoots, but also the distribution of 137Cs to the grains. However, the decrease of 137Cs distribution to the grain had a much smaller effect on 137Cs accumulation in the grains than 137Cs absorption. A positive correlation was also observed between the exchangeable 137Cs/K ratio in the soil and the 137Cs/K ratio in the shoots for each growth stage, and the 137Cs/K ratios in the shoots at the full seed and full maturity stage were much higher than those at the fifth trifoliate and full bloom stage under the same exchangeable 137Cs/K ratio in the soil. These findings suggest a decrease in the discrimination of 137Cs from K during absorption after the full bloom stage. As a result of this and the increase in soil-exchangeable 137Cs/K with growth, radiocesium was more transferable to the shoots after the full bloom stage. Overall, these results suggest that lowering the soil-exchangeable radiocesium/potassium ratio after the full bloom stage by increasing K availability could efficiently reduce the transfer of radiocesium to the grains., 24713133
  • Review: Agricultural Countermeasure against Radiocesium Contaminated Field
    信濃卓郎
    Journal of Biomedical Research and Environmental Sciences, 4, 2, 228, 231, 2021年04月, [査読有り], [招待有り], [筆頭著者]
    英語, 研究論文(学術雑誌), 24713133
  • Comparative study of radioactive cesium transfer from soil to peanut and soybean
    Katashi Kubo, Hayato Maruyama, Hisae Fujimoto, Masataka Suzuki, Ayane Kan, Yusuke Unno, Takuro Shinano
    Soil Science and Plant Nutrition, 67, 6, 707, 715, TAYLOR & FRANCIS LTD, 2021年, [査読有り], [最終著者]
    英語, 研究論文(学術雑誌), Low transfer of radioactive cesium (radiocesium) from soil to grains of agricultural crops is desirable to ensure food safety for humans and animals. Although the transfer of radiocesium from soil to grains is higher in upland crops such as soybean (Glycine max L.) than in paddy rice (Oryza sativa L.), little information related to the specific difference in radiocesium accumulation among leguminous crops is available, or for the relation between soil conditions and radiocesium accumulation in leguminous crops. This study compared the pattern of radiocesium transfer from soil to grains between peanut (Arachis hypogaea L.) and soybean to elucidate the diversity of radiocesium accumulation in leguminous crops growing with different potassium levels in soil. Pot and field experiments with radiocesium-contaminated soil showed that the radiocesium concentration in grains was lower in peanut than in soybean plants. For peanut, radiocesium absorption was mainly from roots instead of gynophores and fruits formed in the soil. Radiocesium absorption and translocation from roots to shoots were lower in peanut than in soybean plants. Among shoot parts, radiocesium transfers from stems to leaves, shells, and grains were lower in peanut than in soybean plants. Potassium application to the soil decreased the radiocesium transfer from soil to grains in both crops. The radiocesium accumulation was lower in peanut than in soybean under both potassium applied and non-applied conditions. These results underscored the variation in radiocesium transfer from soil to grains in leguminous crops, and demonstrated that peanut plants had lower potential of radiocesium accumulation than soybean plants.
  • P4-4-3 温度処理にともなう元素吸収・分配がパプリカの尻腐れ果発症に与える影響(4-4 植物の代謝成分と農作物の品質 2021年度北海道大会)
    鳥山 星呂, 荒川 竜太, 村島 和基, 丸山 隼人, 信濃 卓郎, 渡部 敏裕
    日本土壌肥料学会講演要旨集, 67, 78, 78, 一般社団法人 日本土壌肥料学会, 2021年
    日本語
  • 4-4-2 異なる窒素条件下におけるパプリカ果実の元素組成と尻腐れ果発症との関係(4-4 植物の代謝成分と農作物の品質 2021年度北海道大会)
    荒川 竜太, 村島 和基, 渡部 敏裕, 信濃 卓郎, 丸山 隼人
    日本土壌肥料学会講演要旨集, 67, 76, 76, 一般社団法人 日本土壌肥料学会, 2021年
    日本語
  • 4-4-3 異なる窒素条件下におけるパプリカ果実の機能性成分解析(4-4 植物の代謝成分と農作物の品質 2021年度北海道大会)
    村島 和基, 荒川 竜太, 丸山 隼人, 渡部 敏裕, 信濃 卓郎
    日本土壌肥料学会講演要旨集, 67, 76, 76, 一般社団法人 日本土壌肥料学会, 2021年
    日本語
  • Soil and vegetation sampling during the early stage of Fukushima Daiichi Nuclear Power Plant accident and the implication for the emergency preparedness for agricultural systems.
    Yuichi Onda, Lieve Sweeck, Takuro Shinano, Gerd Dercon, A Lee Zhi Yi, H Kato
    Journal of environmental radioactivity, 223-224, 106373, 106373, 2020年11月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, immediate soil and vegetation sampling were conducted according to the action plan of nuclear emergency monitoring; however, analysing the monitoring dataset was difficult because the sampling protocols were not standardised. In this study, the sampling protocols applied just after the FDNPP accident were reviewed, and the monitoring data were analysed. The detailed protocols and results can provide a sound basis for guidelines of soil and vegetation sampling for nuclear emergency monitoring. The activity concentrations of 137Cs and 131I in weed samples measured immediately after the FDNPP accident were related to the air dose rate at 1 m. Consequently, vegetation sampling is recommended when the additional dose rate (above background) is higher than 0.1 μSv/h. To enhance the efficiency of a protective response in the case of a nuclear accident, predetermined sampling points for soil and vegetation sampling should be considered in the preparedness plan for nuclear emergencies. Furthermore, sampling and analytical measurement capacities (time, people, cost) during the early phase after nuclear emergencies need to be considered in the preparedness and action plan, and sampling and measurement exercises are highly recommended.
  • Metabolomic analysis of night-released soybean root exudates under high- and low-K conditions
    Tantriani, Takuro Shinano, Weiguo Cheng, Kazuki Saito, Akira Oikawa, Benito Heru Purwanto, Keitaro Tawaraya
    PLANT AND SOIL, 456, 1-2, 259, 276, SPRINGER, 2020年11月, [査読有り]
    英語, 研究論文(学術雑誌), Aims Root exudates of soybean grown under low-, normal-, and high-K(+)conditions were evaluated using metabolomics. Methods Two soybean cultivars, 'Satonohohoemi' (low-K-tolerant) and 'Tachinagaha' (low-K sensitive), were hydroponically grown with 6 (K6), 60 (K60), and 120 (K120) mg K L(-1)for 7 and 14 days after transplanting (DAT). Root exudates were collected, and metabolites were evaluated using capillary electrophoresis time-of-flight mass spectrometry. Results Rroot K concentration was lower in K6 and higher in K120 compared to K60. Number of metabolites detected in 'Satonohohoemi' and 'Tachinagaha' was 43 and 39, respectively. Score plot of the principal component analysis (PCA) showed a clear grouping of the root exudate metabolites based one three K concentrations and two sampling times, with the first PCA accounting for 65.7% and 71.5% of the variance for the 'Satonohohoemi' and 'Tachinagaha', respectively. High-K conditions enhanced release of root exudate metabolites to rhizosphere in both soybean cultivars from 18% to 42%. However, low-K conditions resulted in a 1.2-fold increase and a 2.5-fold decrease in the release of root exudate metabolites in 'Tachinagaha' and 'Satonohohoemi', respectively, at 7 and 14 DAT. Conclusions These results reveal that soybean roots exude many metabolites in response to high- and low-K conditions. The number of increased metabolites was higher after long-term (14 DAT) compared to that of the short-term (7 DAT) of exposure of high- and low-K conditions. Soybean cultivars differ in the capacity to release metabolites by altering the exudation of specific metabolites for a better adaptation to the high- and low-K conditions.
  • Dynamics of radionuclide activity concentrations in weed leaves, crops and of air dose rate after the Fukushima Daiichi Nuclear Power Plant accident.
    Sergey Fesenko, Takuro Shinano, Yuichi Onda, Gerd Dercon
    Journal of environmental radioactivity, 222, 106347, 106347, 2020年10月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), © 2020 Elsevier Ltd Data on reduction of radioactivity in plants are highly important for making decision on emergency response and remediation of contaminated areas. Dynamics of the 131I and 137Cs concentrations in the weed leaves sampled in the areas affected by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan was assessed for the period March–December 2011. The effective half-lives for 131I and 137Cs of 3.8–4.2 days and 7.1–13.3 days in the weed leaves were calculated for the first two months after the deposition. The approach for assessment of the aggregated transfer factors based on the ambient dose equivalent rate was suggested and validated. The geometric means of the soil to the weed leaves aggregated transfer factors were estimated for June–December 2011. Soil to crop 137Cs- concentration ratios (buckwheat, brown rice and soybean) were estimated for 2011–2016. Soil to crop concentration ratios were found to decrease in the order of soybean > buckwheat > brown rice. The effective half-lives for 137Cs in these crops were estimated to be between 1 and 2.5 years for the period 2011 2016, and longer than 5–7 years after 2016. It was found that these data comply with the Chernobyl related data obtained for similar conditions and complement of international documents on radionuclide transfer in agricultural environment such as the IAEA TRS 472.
  • Relationships between air dose rates and radionuclide concentrations in agricultural plants observed in areas affected by the Fukushima Dai-ichi accident.
    Takuro Shinano, Mayumi Hachinohe, Sergey Fesenko
    Journal of environmental radioactivity, 222, 106359, 106359, 2020年10月, [査読有り], [筆頭著者], [国際誌]
    英語, 研究論文(学術雑誌), © 2020 Elsevier Ltd Most of environmental monitoring programs include measurements of the air dose rates and the radionuclides activity concentration in plants. Both these parameters depend on deposition density of radionuclides. Therefore, measurements of one parameter can (with some supplementary information) be used as an indicator for the other parameter. After the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, the Emergency Operation Centre (EOC) operated by the Environmental Radioactivity Monitoring centre of Fukushima and Ministry of Agriculture, Forestry and Fisheries (MAFF) of Japan carried out large sampling programme over different distances from the NPP. The sampling programme was focused on the usage of the weed leaves as a proxy for the prediction of radionuclide transfer to some cultivated plants. The MAFF monitoring programme in 2011–2016 was addressed mainly to agricultural crops. In both cases, the air dose rates were measured at the sites of the sampling. The paper addresses the assessments of relationship between radionuclide activities concentrations in plants and ambient dose rates. The time—dependent relationships were quantified based on weed, buckwheat, brown rice and soybean data obtained in 2011–2016. The recommendations on optimizing emergency sampling programmes based on use of the data of ambient dose rates are also presented.
  • Large-scale agricultural soil and food sampling and radioactivity analysis during nuclear emergencies in Japan: Development of technical and organisational procedures for soil and food sampling after the accident.
    Mayumi Hachinohe, Takuro Shinano
    Journal of environmental radioactivity, 220-221, 106265, 106265, 2020年09月01日, [査読有り], [責任著者], [国際誌]
    英語, 研究論文(学術雑誌), Copyright © 2020 Elsevier Ltd. All rights reserved. Most available measurement methods and protocols for radioactive materials are focused on the use of high-precision sampling and analysis and do not consider the practicality of these techniques in the case of large-scale emergencies involving high numbers of samples and measurements. The experience gained after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has demonstrated a need for optimization of sampling and measurement programmes in the case of nuclear emergency that affects food and agriculture. Under these conditions, resources for implementation of monitoring and allocations for sampling and measurements might be limited, and urgent information is needed for effective emergency response. This paper supplies a historical overview of sampling and analytical techniques for assessment of radionuclides in the agricultural environments and foodstuffs and is intended for use in research, policy and decision-making in nuclear emergency preparedness and response, particularly with respect to large scale accidents.
  • Sampling, analysis and modelling technologies for large-scale nuclear emergencies affecting food and agriculture.
    Gerd Dercon, Carl Blackburn, Yuichi Onda, Takuro Shinano, Lieve Sweeck, Amelia Lee Zhi Yi, Sergey Fesenko
    Journal of environmental radioactivity, 218, 106174, 106174, 2020年07月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Large-scale sampling and radioactivity analysis of agricultural soil and food during nuclear emergencies in Japan: Variations over time in foodstuffs inspection and sampling.
    Mayumi Hachinohe, Takuro Shinano
    Journal of environmental radioactivity, 218, 106262, 106262, 2020年07月, [査読有り], [責任著者], [国際誌]
    英語, 研究論文(学術雑誌), © 2020 Elsevier Ltd The measurement of radioactivity in food and agricultural ecosystems is an essential task for keeping the population safe after a nuclear emergency. Prior to the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011, the probability of such an accident, combining complex effects of natural and technical factors, was not reflected in detail in national emergency preparedness guidelines. The lack of such guidelines resulted in a limited efficiency response to the Fukushima accident in agriculture. This outcome showed a need for the preparation of such guidelines as a part of emergency preparedness for nuclear and radiological emergences. This paper provides information and generic, non-country-specific guidance on approaches to sampling food. The paper is intended for scientists, policy makers and decision makers involved in nuclear emergency preparedness and responses, particularly on large scales and at different stages of nuclear emergency based on lessons learned from the FDNPP accident.
  • Visualising spatio-temporal distributions of assimilated carbon translocation and release in root systems of leguminous plants.
    Yong-Gen Yin, Nobuo Suzui, Keisuke Kurita, Yuta Miyoshi, Yusuke Unno, Shu Fujimaki, Takuji Nakamura, Takuro Shinano, Naoki Kawachi
    Scientific reports, 10, 1, 8446, 8446, NATURE PUBLISHING GROUP, 2020年06月11日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), © 2020, The Author(s). The release of rhizodeposits differs depending on the root position and is closely related to the assimilated carbon (C) supply. Therefore, quantifying the C partitioning over a short period may provide crucial information for clarifying root–soil carbon metabolism. A non-invasive method for visualising the translocation of recently assimilated C into the root system inside the rhizobox was established using 11CO2 labelling and the positron-emitting tracer imaging system. The spatial distribution of recent 11C-photoassimilates translocated and released in the root system and soil were visualised for white lupin (Lupinus albus) and soybean (Glycine max). The inputs of the recently assimilated C in the entire root that were released into the soil were approximately 0.3%–2.9% for white lupin within 90 min and 0.9%–2.3% for soybean within 65 min, with no significant differences between the two plant species; however, the recently assimilated C of lupin was released at high concentrations in specific areas (hotspots), whereas that of soybean was released uniformly in the soil. Our method enabled the quantification of the spatial C allocations in roots and soil, which may help to elucidate the relationship between C metabolism and nutrient cycling at specific locations of the root–soil system in response to environmental conditions over relatively short periods.
  • Reduction in the Radiocesium in Meats of the Sika Deer and Wild Boar by Cooking.
    Mayumi Hachinohe, Ryusuke Fujimoto, Takuro Shinano, Eiichi Kotake-Nara, Shioka Hamamatsu, Shinichi Kawamoto
    Journal of food protection, 83, 3, 467, 475, 2020年03月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Copyright © International Association for Food Protection. The behavior of radiocesium in wild animal meats upon cooking was investigated. The ratio of the concentration change (processing factor, Pf), remaining ratio (food processing retention factor, Fr), and removal ratio of radiocesium in the meats by grilling, boiling, and steaming were determined. Differences in cooking methods, rather than differences in meat parts or animal species, clearly influenced the Pf, Fr, and removal ratios. The mean Fr values were 0.9 (range, 0.7 to 1.0) for grilling, 0.6 (range, 0.4 to 0.7) for boiling, and 0.5 (range, 0.4 to 0.7) for steaming. The removal effect of grilling (11%) was lower than that of boiling (41%) or steaming (47%). The mean value of Pf was 1.2 (range, 1.1 to 1.6) for grilling, 0.8 (range, 0.6 to 0.9) for boiling, and 0.8 (range, 0.7 to 1.0) for steaming. The radiocesium concentration in the meats increased only upon grilling, but not by boiling or steaming. This difference is due to the lower removal effect of grilling than that of boiling and steaming. Therefore, boiling and steaming were more effective than grilling for removing radiocesium and reducing its concentration in wild animal meats. Furthermore, the ratio of water content fluctuations due to boiling was negatively correlated with Pf and Fr. It was evident that greater reductions in water content resulted in lower concentrations and improved radiocesium removal in the meats. These results suggest that some of the radiocesium naturally present in the meats is soluble in water and that the radiocesium dissolved in water can be removed from the meat with the release of water from the tissue.
  • Comparisons of effective half-lives of radiocesium in Japanese tea plants after two nuclear accidents, Chernobyl and Fukushima.
    Keiko Tagami, Shigeo Uchida, Takuro Shinano, Gerhard Pröhl
    Journal of environmental radioactivity, 213, 106109, 106109, 2020年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), The time-dependence of 137Cs in new shoots of tea (Camellia sinensis (L.) Kuntze) following a137Cs-deposition was analyzed and quantified in terms of effective half-lives. The underlying monitoring studies were performed after the accidents in the Chernobyl and the Fukushima Daiichi nuclear power plants for tea plants growing in Japan. The major transfer route for atmospherically deposited radiocaesium to the first new shoots sampled after the accidents were different: for the Fukushima accident, it was mainly translocation of radiocaesium deposited onto old leaves and twigs to the new growth, while direct deposition on the new leaves was the major source after the Chernobyl accident. The effective half-lives in new tea leaves representing the fast and slow components of the decline did not significantly differ between these accidents. Geometric means (ranges) of fast and slow effective half-lives of 137Cs after the Chernobyl accident were 66 d (25-125 d) and 902 d (342-15900 d), respectively, and those after the Fukushima accident were 50 d (26-105 d) and 416 d (222-1540 d), respectively. From these results, 137Cs declines in new tea leaves were similar although contamination conditions were different for these two accidents.
  • Variations in radioactive cesium accumulation in wheat germplasm from fields affected by the 2011 Fukushima nuclear power plant accident.
    Katashi Kubo, Hiroyuki Kobayashi, Miyuki Nitta, Shotaro Takenaka, Shuhei Nasuda, Shigeto Fujimura, Kyoko Takagi, Osamu Nagata, Takeshi Ota, Takuro Shinano
    Scientific reports, 10, 1, 3744, 3744, 2020年02月28日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Decreasing the transfer of radioactive cesium (RCs) from soil to crops has been important since the deposition of RCs in agricultural soil owing to the Fukushima nuclear power plant accident of 2011. We investigated the genotypic variation in RCs accumulation in 234 and 198 hexaploid wheat (Triticum spp.) varieties in an affected field in 2012 and 2013, respectively. The effects of soil exchangeable potassium (ExK) content to RCs accumulation in wheat varieties were also evaluated. A test field showed fourfold differences in soil ExK contents based on location, and the wheat varieties grown in areas with lower soil ExK contents tended to have higher grain RCs concentrations. RCs concentrations of shoots, when corrected by the soil ExK content, were positively significantly correlated between years, and RCs concentrations of shoots were significantly correlated with the grain RCs concentration corrected by the soil ExK content. These results indicated that there were genotypic variations in RCs accumulation. The grain to shoot ratio of RCs also showed significant genotypic variation. Wheat varieties with low RCs accumulations were identified. They could contribute to the research and breeding of low RCs accumulating wheat and to agricultural production in the area affected by RCs deposition.
  • Factors controlling dissolved 137Cs concentrations in east Japanese Rivers.
    Hideki Tsuji, Yumiko Ishii, Moono Shin, Keisuke Taniguchi, Hirotsugu Arai, Momo Kurihara, Tetsuo Yasutaka, Takayuki Kuramoto, Takahiro Nakanishi, Sangyoon Lee, Takuro Shinano, Yuichi Onda, Seiji Hayashi
    The Science of the total environment, 697, 134093, 134093, 2019年12月20日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), To investigate the main factors that control the dissolved radiocesium concentration in river water in the area affected by the Fukushima Daiichi nuclear power plant accident, the correlations between the dissolved 137Cs concentrations at 66 sites normalized to the average 137Cs inventories for the watersheds with the land use, soil components, topography, and water quality factors were assessed. We found that the topographic wetness index is significantly and positively correlated with the normalized dissolved 137Cs concentration. Similar positive correlations have been found for European rivers because wetland areas with boggy organic soils that weakly retain 137Cs are mainly found on plains. However, for small Japanese river watersheds, the building area ratio in the watershed strongly affected the dissolved 137Cs concentration. One reason for this would be because the high concentrations of solutes, such as K+ and dissolved organic carbon, discharged in urban areas would inhibit 137Cs absorption to soil particles. A multiple regression equation was constructed to predict the normalized dissolved 137Cs concentration with the topography, land use, soil component, and water quality data as explanatory variables. The best model had the building land use as the primary predictor. When comparing two multiple regression models in which the explanatory variables were limited to (1) the land use and soil composition and (2) the water quality, the water quality model underestimated the high normalized dissolve 137Cs concentration in urban areas. This poor reproducibility indicates that the dissolved 137Cs concentration value in urban areas cannot be solely explained by the solid-liquid distribution of 137Cs owing to the influence of the water quality, but some specific 137Cs sources in urban areas would control the dissolved 137Cs concentration.
  • The extractability of potassium and radiocaesium in soils developed from granite and sedimentary rock in Fukushima, Japan
    Ogasawara, S, Nakao, A, Eguchi, T, Ota, T, Matsunami, H, Yanai, J, Shinano, T
    Journal of Radioanalytical and Nuclear Chemistry, 323, 1, 633, 640, 2019年11月30日, [査読有り]
    英語, 研究論文(学術雑誌), © 2019, Akadémiai Kiadó, Budapest, Hungary. Potassium (K) and radiocaesium (RCs) were chemically extracted from soils derived from granite (G soils) and sedimentary rock (S soils) in Fukushima, Japan. The extractants employed were 1 M HNO3, concentrated HNO3, and HF + HClO4. As S soils contain a lower amount of trioctahedral 2:1 phyllosilicates than G soils, the RCs/K ratio was higher in S soils than in G soils with 1 M HNO3 extraction, indicating that the potential risk of soil-to-plant transfer of RCs is higher in S soils than in G soils. In conclusion, information about surface geology is important in predicting the spatial pattern of soil characteristics related to transferability of RCs.
  • Repeatability and reproducibility of measurements of low dissolved radiocesium concentrations in freshwater using different pre-concentration methods
    Momo Kurihara, Tetsuo Yasutaka, Tatsuo Aono, Nobuo Ashikawa, Hiroyuki Ebina, Takeshi Iijima, Kei Ishimaru, Ramon Kanai, Zin'ichi Karube, Yae Konnai, Tomijiro Kubota, Yuji Maehara, Takeshi Maeyama, Yusuke Okizawa, Hiroaki Ota, Shigeyoshi Otosaka, Aya Sakaguchi, Hisaya Tagomori, Keisuke Taniguchi, Masatoshi Tomita, Hirofumi Tsukada, Seiji Hayashi, Sangyoon Lee, Susumu Miyazu, Moono Shin, Takahiro Nakanishi, Tatsuhiro Nishikiori, Yuichi Onda, Takuro Shinano, Hideki Tsuji
    JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY, 322, 2, 477, 485, SPRINGER, 2019年11月, [査読有り]
    英語, 研究論文(学術雑誌), We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (Prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the Cs-137 results were within +/- 2, indicating that the methods were a good degree of precision. The relative standard deviations (RSDs) indicating the reproducibility among different laboratories were larger than the RSDs indicating the repeatability in each separate laboratory.
  • 屋上緑化芝地における大気汚染に関わる元素量の経年変化
    黒沼尊紀, 久保堅司, 信濃卓郎, 石原竜彰, 孔大徳, 東島一成, 安藤匡哉, 渡部均
    日本緑地工学会誌, 45, 1, 33, 38, 2019年10月, [査読有り]
    日本語
  • Rapid Quantification of Radioactive Strontium-90 in Fresh Foods via Online Solid-Phase Extraction-Inductively Coupled Plasma-Dynamic Reaction Cell-Mass Spectrometry and Its Comparative Evaluation with Conventional Radiometry.
    Makoto Furukawa, Kyoko Takagi, Hisaya Matsunami, Yuko Komatsuzaki, Tomohiko Kawakami, Takuro Shinano, Yoshitaka Takagai
    ACS omega, 4, 6, 11276, 11284, 2019年06月30日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), This paper describes a rapid quantification method for radioactive strontium (90Sr) in fresh foods (perishable foods) and has been comparatively evaluated with the common classical radiometric quantification method. Inductively coupled plasma-dynamic reaction cell-mass spectrometry with online solid-phase extraction (cascade-ICP-MS) rapidly determines 90Sr in a pure water-based sample. Despite its advantages, its application to fresh foods (perishable foods) has not yet been reported; however, the analytical potential of this method for fresh foods must be evaluated. In this study, 90Sr was determined in 12 fresh foods via improved cascade-ICP-MS (Icas-ICP-MS). Addition and recovery tests were demonstrated using real samples of grape, apple, peach, Japanese pear, rice, buckwheat, soybean, spinach, shiitake mushroom, grass, sea squirt, and flounder. With a decomposed solution of Japanese pear, the measurement value coincided with the amount of spiked 90Sr. The reproducibility of the measurements was represented by relative standard deviations of 14.2 and 5.0% for spiked amounts of 20 and 200 Bq/kg, respectively (n = 10), and the recovery rates were 93.7 ± 7.1%. In this case, the limit of detection (LOD) was 2.2 Bq/kg (=0.43 pg/kg). These results were compared with the data obtained using a common classical radiometric quantification method (nitrate precipitation-low background gas flow counter (LBC) method) in the same samples. Both the methods showed equivalent performances with regard to reproducibility, precision, and LODs but different analysis times. Icas-ICP-MS required ∼22 min for analysis, whereas the nitrate precipitation-LBC method required 20 days, confirming that Icas-ICP-MS is the suitable method for analyzing 90Sr in fresh foods.
  • Rapid Quantification of Radioactive Strontium-90 in Fresh Foods via Online Solid-Phase Extraction-Inductively Coupled Plasma-Dynamic Reaction Cell-Mass Spectrometry and Its Comparative Evaluation with Conventional Radiometry
    Makoto Furukawa, Kyoko Takagi, Hisaya Matsunami, Yuko Komatsuzaki, Tomohiko Kawakami, Takuro Shinano, Yoshitaka Takagai
    ACS OMEGA, 4, 6, 11276, 11284, AMER CHEMICAL SOC, 2019年06月, [査読有り]
    英語, 研究論文(学術雑誌), This paper describes a rapid quantification method for radioactive strontium (Sr-90) in fresh foods (perishable foods) and has been comparatively evaluated with the common classical radiometric quantification method. Inductively coupled plasma-dynamic reaction cell-mass spectrometry with online solid-phase extraction (cascade-ICP-MS) rapidly determines Sr-90 in a pure water-based sample. Despite its advantages, its application to fresh foods (perishable foods) has not yet been reported; however, the analytical potential of this method for fresh foods must be evaluated. In this study, Sr-90 was determined in 12 fresh foods via improved cascade-ICP-MS (Icas-ICP-MS). Addition and recovery tests were demonstrated using real samples of grape, apple, peach, Japanese pear, rice, buckwheat, soybean, spinach, shiitake mushroom, grass, sea squirt, and flounder. With a decomposed solution of Japanese pear, the measurement value coincided with the amount of spiked Sr-90. The reproducibility of the measurements was represented by relative standard deviations of 14.2 and 5.0% for spiked amounts of 20 and 200 Bq/kg, respectively (n = 10), and the recovery rates were 93.7 +/- 7.1%. In this case, the limit of detection (LOD) was 2.2 Bq/kg (=0.43 pg/kg). These results were compared with the data obtained using a common classical radiometric quantification method (nitrate precipitation-low background gas flow counter (LBC) method) in the same samples. Both the methods showed equivalent performances with regard to reproducibility, precision, and LODs but different analysis times. Icas-ICP-MS required similar to 22 min for analysis, whereas the nitrate precipitation-LBC method required 20 days, confirming that Icas-ICP-MS is the suitable method for analyzing Sr-90 in fresh foods.
  • Phytoavailability of 137Cs and stable Cs in soils from different parent materials in Fukushima, Japan.
    Sho Ogasawara, Tetsuya Eguchi, Atsushi Nakao, Shigeto Fujimura, Yoshihiko Takahashi, Hisaya Matsunami, Hirofumi Tsukada, Junta Yanai, Takuro Shinano
    Journal of environmental radioactivity, 198, 117, 125, 2019年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Weathered micaceous minerals (micas) are able to release potassium ion (K+) and fix caesium-137 (137Cs), both of which reduce soil-to-plant transfer of 137Cs. Among micas, trioctahedral micas such as biotite is expected to have a stronger ability to supply nonexchangeable K+ and a higher amount of Cs fixation sites than dioctahedral micas such as illite. Although biotite is predominant in granitic soils (G soils), illite is mainly dominant in sedimentary rock soils (S soils). Therefore, we hypothesized that G soils have a lower 137Cs transfer risk than S soils because of this difference in mineralogy. The objective of the present study was to determine the transfer factor (TF) of 137Cs and stable Cs (SCs) and to elucidate the determinant factors of TFs for G and S soils in Fukushima, Japan. Pot experiments were carried out with rice (Oryza sativa L. cv. Hokuriku 193) in G and S soils to determine the TF of 137Cs (TF-137Cs) and stable Cs (TF-SCs) under K-deficient conditions. TF-137Cs and TF-SCs were highly correlated, and both were significantly lower for G soils than for S soils. Higher TF values were shown for soils with lower amounts of exchangeable and nonexchangeable K or with higher percentages of exchangeable 137Cs (ex137Cs). The percentage of ex137Cs was negatively correlated with the amount of Cs fixation sites, represented by the radiocaesium interception potential. Thus, we concluded that smaller TF values for G soils were caused by a stronger ability to supply nonexchangeable K+ and a higher amount of Cs fixation sites. These findings will contribute to the establishment of soil screening techniques based on 137Cs transfer risk in Fukushima prefecture.
  • A reduced phosphorus application rate using a mycorrhizal plant as the preceding crop maintains the soybean seeds’ nutritional quality
    SHA, ZM, WATANABE, CHU, Q, OKA, N, OSAKI, M, SHINANO Takuro
    Journal of Agricultural and Food Chemistry, 67, 1, 32, 42, 2019年01月09日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), We tested whether introducing an arbuscular mycorrhizal fungi (AMF)-host plant with a reduced P application rate could maintain soybean seeds' nutrient quality. The dynamic variation of 14 nutrients was analyzed in source and sink organs during the seed-filling stage. The AMF-host and non-AMF-host plants, sunflower and mustard, were grown as preceding crops (PCs). Soybeans, the succeeding crops, were planted with three different phosphorus levels, namely, 0, 50, and 150 kg P2O5 ha-1. The results showed that the AMF-host PC with a reduced P application rate maintained the seed's yield and nutrients quality. During the seed-filling stage, the AMF-host PC with a reduced P application rate increased the uptake of most nutrients compared to the non-AMF-host PC, and improved the remobilization efficiency of all nutrients except Mn, Fe, and Se, compared to the optimal P application rate. These results could help improve the utilization efficiency of P fertilizers and protect soybeans' nutritional value.
  • A statistical model for estimating the radiocesium transfer factor from soil to brown rice using the soil exchangeable potassium content.
    Kohji Yamamura, Shigeto Fujimura, Takeshi Ota, Tetsuya Ishikawa, Takashi Saito, Yoshimitsu Arai, Takuro Shinano
    Journal of environmental radioactivity, 195, 114, 125, ELSEVIER SCI LTD, 2018年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), To reduce radiocesium uptake by rice, large amounts of potassium fertilizer have been applied to paddy fields contaminated by radiocesium released from the Fukushima Dai-ichi Nuclear Power Plant owned by the Tokyo Electric Power Company. The Fukushima Prefectural Government recommended maintenance of the soil exchangeable K content up to 200 mg K kg-1 before conventional fertilization in rice production. We constructed an equation to predict the transfer factor from soil to brown rice using the soil exchangeable K content. This equation was then used to calculate the appropriate soil exchangeable K content, which ensures a low risk (5%) of brown rice exceeding the standard limit (100 Bq kg-1 for grains) established in 2012. The equations were constructed using field data obtained by an investigation (measurement of the 137Cs concentrations in soil and brown rice and measurement of the soil exchangeable K content at harvest) that was performed from 2012 to 2015 in 321 paddy fields distributed all over Fukushima Prefecture. We found that the stochastic fluctuation of the transfer factor approximately follows a lognormal distribution under the given environmental conditions. Four factors are considered in predicting the logarithmic quantity of the transfer factor: (1) the linear influence of the logarithm of the exchangeable K content in soil, (2) the non-linear influence of the logarithm of the exchangeable K content in soil, (3) three districts in the Fukushima Prefecture and (4) the year. The linear model of the logarithm of exchangeable K content in soil was adopted by the RD criterion, which indicates the absolute goodness of models for prediction. The predictive ability of the model increased by 29% after including the logarithm of the exchangeable K content in soil (factor 1), while the predictive ability further increased by 10% after including spatial and temporal information (factors 3 and 4). The validity of the exchangeable K content recommended by the Fukushima Prefectural Government was re-examined using the proposed equations, which indicated that the conventional recommendation was appropriate at 2012 but is not fully appropriate under the current situation in which the radiocesium concentration in soil has decreased.
  • Towards the partial resumption of agriculture with buckwheat cultivation in fields physically decontaminated of radioactive cesium after the nuclear power plant accident in 2011: A case study in Yamakiya District, Fukushima.
    Kubo, T, Kobayashi, H, Fujimoto, R, Ota, T, Shinano, T
    Plant Production Science, 2018年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • P and N deficiency change the relative abundance and function of rhizosphere microorganisms during cluster root development of white lupin (Lupinus albus L.).
    Wasaki, J, Sakaguchi, J, Yamamura, T, Ito, S, Shinano, T, Osaki, M, Kandeler, E. P
    Soil Science and Plant Nutrition, 64, 6, 686, 696, TAYLOR & FRANCIS LTD, 2018年11月, [査読有り]
    英語, 研究論文(学術雑誌), We studied microbe-plant interactions of white lupin, a cluster root-forming plant, under low P and N conditions to examine increased nutrient acquisition by plants either by a shift to a more specialized microbial community or changes in microbial enzyme production. White lupin plants were grown in rhizoboxes filled with either P- or N-deficient soil; fertilized soil was used as control. After cultivation of plants in a glasshouse for 41 d, plant growth (shoot and roots) and P and N accumulation in shoots were measured. Microbial functions were analyzed by P- and N-cycling enzymes. The microbial community structure was estimated by fingerprinting (denaturing gradient gel electrophoresis) and sequencing techniques. P deficiency induced the released citrate and acid phosphomonoesterases from cluster roots and stimulated the production of microbe-derived alkaline phosphomonoesterase in the rhizosphere. P deficiency decreased microbial diversity in the cluster root rhizosphere. Increased relative abundance of Burkholderiales in the rhizosphere of P deficient plants might be responsible for the degradation of different organic P fractions such as phytates. N deficiency induced an increase of the number of nodules and P concentration in shoot as well as roots of white lupin. We clarified that high release of citrate from cluster roots might be the preferred mechanisms to meet the P demand of nodulated plants under N deficiency. In addition, the high abundance of Rhizobiales and Rhodospirillales in the rhizosphere of cluster roots showed that the importance of N-fixing microorganisms under N deficiency. The contribution of rhizosphere microorganisms due to similar activities of N-cycling enzymes under the two different N treatments is less important for N nutrition of plants. Further understanding of the regulation of cluster roots under N-deficiency will provide new information on the interactions between P and N nutrition.
  • Dynamic changes in the Cs distribution throughout rice plants during the ripening period, and effects of the soil-K level
    Junko Ishikawa, Shigeto Fujimura, Motohiko Kondo, Mari Murai-Hatano, Akitoshi Goto, Takuro Shinano
    Plant and Soil, 429, 1-2, 1, 16, Springer International Publishing, 2018年06月16日, [査読有り]
    英語, 研究論文(学術雑誌), Background and aims: Radiocesium uptake and accumulation in crops has been studied in Japan since the March 2011 nuclear power plant accident. However, few studies have reported how cesium (Cs) is distributed in aboveground parts and how it accumulates in edible parts. Here, we report the dynamics of Cs in aboveground parts of rice (Oryza sativa L.) plants throughout the cultivation period, and the effects of the amount of potassium (K) fertilizer applied to the soil. Methods: We conducted two years of pot experiments with several soil-K levels and examined the K and Cs concentrations in each plant part throughout the cultivation period. Results: During ripening, Cs accumulated most in the panicle neck. The ratio of the Cs concentration in brown rice to that in the straw was negatively correlated with the soil-K level, indicating that the proportion of Cs accumulated in the brown rice to that in the whole-aboveground parts increased at low soil K. During ripening, transport of Cs from belowground parts and translocation from leaf blades both seemed to increase at low soil K. Conclusion: The Cs distribution in plant parts appears to be regulated dynamically during ripening by the soil-K level.
  • セシウム低吸収水稲の Cs/K 吸収特性と現地試験結果(4-3 植物の有害元素,2017年度仙台大会)
    頼, 泰樹, 信濃, 卓郎, 永澤, 信洋, 我彦, 廣悦, 中村, 進一, 服部, 浩之, 横山, 咲, 佐藤, 奈美子, 古川, 純, 能美, 多希子, 伊藤, 那香, 森田, 祥司, 藤村, 恵人, 後藤, 明俊
    日土肥講要, 63, 0, 75, 75, 一般社団法人 日本土壌肥料学会, 2018年05月
    日本語, 研究論文(研究会,シンポジウム資料等)
  • Potassium behavior and clay mineral composition in the soil with low effectiveness of potassium application
    Katashi Kubo, Takashi Hirayama, Shigeto Fujimura, Tetsuya Eguchi, Naoto Nihei, Shoichiro Hamamoto, Megumi Takeuchi, Takashi Saito, Takeshi Ota, Takuro Shinano
    Soil Science and Plant Nutrition, 64, 2, 265, 271, Taylor and Francis Ltd., 2018年03月04日, [査読有り]
    英語, 研究論文(学術雑誌), Increasing exchangeable potassium (ExK) content in soil to an appropriate level is important to mitigate the transfer of radioactive cesium to crops. We focused on a buckwheat (Fagopyrum esculentum Moench) field with a low ExK content, despite the application of K, in Fukushima Prefecture, Japan (Field A), following the Tokyo Electric Power Company Fukushima Dai-ichi (No. 1) Nuclear Power Plant accident in March 2011. We examined the relationship between K concentration and clay mineral composition in the soil of Field A and compared the findings with another field in Fukushima Prefecture (Field B) to clarify whether K applied to the soil was leached or remaining fixed. Pot experiments showed that K concentration in water seepage from pots following irrigation was significantly lower in pots from Field A than in those from Field B. Soil ExK content after soybean cultivation was lower in soils of Field A than those of Field B. These results indicate that K applied to Field A was fixed in the soil. Analysis of clay mineral composition confirmed the distinctive vermiculitic nature of Field A soils. This clay mineralogy would be associated with the higher K fixation ability of Field A than Field B soils. This study demonstrated that K fixation in vermiculite was a factor preventing the increase in ExK content from K application to Field A.
  • 野焼きを想定した雑草の燃焼による放射性セシウムの動態
    好野奈美子, 堀井幸江, 村上敏文, 松波寿弥, 万福裕造, 信濃卓郎
    環境放射能除染学会誌, 6, 2, 91, 99, 2018年, [査読有り]
    日本語
  • Changes in distribution of Cs in each part of rice plants in ripening period under different soil-K level.               
    Junko Ishikawa, Shigeto Fujimura, Motohiko Kondo, Mari Murai-Hatano, Akitoshi Goto, Takuro Shinano
    Plant Soil, 429, 503, 518, 2018年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cesium Uptake by Rice Roots Largely Depends Upon a Single Gene, HAK1, Which Encodes a Potassium Transporter.
    Hiroki Rai, Saki Yokoyama, Namiko Satoh-Nagasawa, Jun Furukawa, Takiko Nomi, Yasuka Ito, Shigeto Fujimura, Hidekazu Takahashi, Ryuichiro Suzuki, ELMannai Yousra, Akitoshi Goto, Shinichi Fuji, Shin-Ichi Nakamura, Takuro Shinano, Nobuhiro Nagasawa, Hiroetsu Wabiko, Hiroyuki Hattori
    Plant & cell physiology, 58, 11, 2041, 2041, 2017年11月01日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Caesium uptake by rice roots largely depends upon a single gene, HAK1, which encodes a potassium transporter.
    Rai, H, Yokoyama, S, Satoh-Nagasawa, N, Furukawa, J, Nomi, T, Ito, Y, Fujimura, S, Takahashi, H, Suzuki, R, Yousra, E, Goto, A, Fuji, S, Nakamura, S, Shinano, T, Nagasawa, N, Wabiko, H, Hattori, H
    Plant and Cell Physiology, 58, 9, 1486, 1493, 2017年09月01日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Incidents at the Fukushima and Chernobyl nuclear power stations have resulted in widespread environmental contamination by radioactive nuclides. Among them, 137cesium has a 30 year half-life, and its persistence in soil raises serious food security issues. It is therefore important to prevent plants, especially crop plants, from absorbing radiocesium. In Arabidopsis thaliana, cesium ions are transported into root cells by several different potassium transporters such as high-affinity K+ transporter 5 (AtHAK5). Therefore, the cesium uptake pathway is thought to be highly redundant, making it difficult to develop plants with low cesium uptake. Here, we isolated rice mutants with low cesium uptake and reveal that the Oryza sativa potassium transporter OsHAK1, which is expressed on the surfaces of roots, is the main route of cesium influx into rice plants, especially in low potassium conditions. During hydroponic cultivation with low to normal potassium concentrations (0-206 µM: the normal potassium level in soil), cesium influx in OsHAK1-knockout lines was no greater than one-eighth that in the wild type. In field experiments, knockout lines of O. sativa HAK1 (OsHAK1) showed dramatically reduced cesium concentrations in grains and shoots, but their potassium uptake was not greatly affected and their grain yields were similar to that of the wild type. Our results demonstrate that, in rice roots, potassium transport systems other than OsHAK1 make little or no contribution to cesium uptake. These results show that low cesium uptake rice lines can be developed for cultivation in radiocesium-contaminated areas.
  • LjMOT1, a high-affinity molybdate transporter from Lotus japonicus, is essential for molybdate uptake, but not for the delivery to nodules
    Duan Guilan, Hakoyama Tsuneo, Kamiya Takehiro, Miwa Hiroki, Lombardo Fabien, Sato Shusei, Tabata Satoshi, Chen Zheng, Watanabe Toshihiro, Shinano Takuro, Fujiwara Toru
    PLANT JOURNAL, 90, 6, 1108, 1119, 2017年06月, [査読有り], [国際誌]
    英語, Molybdenum (Mo) is an essential nutrient for plants, and is required for nitrogenase activity of legumes. However, the pathways of Mo uptake from soils and then delivery to the nodules have not been characterized in legumes. In this study, we characterized a high-affinity Mo transporter (LjMOT1) from Lotus japonicus. Mo concentrations in an ethyl methanesulfonate-mutagenized line (ljmot1) decreased by 70-95% compared with wild-type (WT). By comparing the DNA sequences of four AtMOT1 homologs between mutant and WT lines, one point mutation was found in LjMOT1, which altered Trp292 to a stop codon; no mutation was found in the other homologous genes. The phenotype of Mo concentrations in F2 progeny from ljmot1 and WT crosses were associated with genotypes of LjMOT1. Introduction of endogenous LjMOT1 to ljmot1 restored Mo accumulation to approximately 60-70% of the WT. Yeast expressing LjMOT1 exhibited high Mo uptake activity, and the Km was 182 nm. LjMOT1 was expressed mainly in roots, and its expression was not affected by Mo supply or rhizobium inoculation. Although Mo accumulation in the nodules of ljmot1 was significantly lower than that of WT, it was still high enough for normal nodulation and nitrogenase activity, even for cotyledons-removed ljmot1 plants grown under low Mo conditions, in this case the plant growth was significantly inhibited by Mo deficiency. Our results suggest that LjMOT1 is an essential Mo transporter in L. japonicus for Mo uptake from the soil and growth, but is not for Mo delivery to the nodules.
  • Plants prioritize phytochelatin synthesis during cadmium exposure even under reduced sulfate uptake caused by the disruption of SULTR1;2
    Yamaguchi Chisato, Ohkama-Ohtsu Naoko, Shinano Takuro, Maruyama-Nakashita Akiko
    PLANT SIGNALING & BEHAVIOR, 12, 5, e1325053, TAYLOR & FRANCIS INC, 2017年05月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Glutathione and phytochelatins are sulfur containing compounds playing an important role in cadmium (Cd) detoxification. We examined the Cd-induced changes in the percentage of sulfur containing compounds to total sulfur in wild-type and sulfate transporter 1;2 knockout mutant, sel1-10. Cd treatment increased the proportion of sulfate and thiols in the total sulfur content. Among the thiols analyzed, the proportion of cysteine and glutathione were decreased by the Cd treatment and that of the phytochelatins were increased. Although the total sulfur content in sel1-10 was decreased compared with that in wild-type, the percentages of individual thiol in the total thiol content were similarly maintained between sel1-10 and wild-type, suggesting that plants tightly controlled the balance of each thiol under Cd treatment.
  • 陸水中における微量溶存態放射性セシウムの濃縮法の比較
    保高徹生, 申文浩, 思田裕, 信濃卓郎, 林誠二, 塚田祥文, 青野辰雄, 飯島和毅, 江口定夫, 大野浩ー, 吉田幸弘, 上東浩, 北村清司, 久保田富次郎, 野川憲夫, 吉川夏樹, 山口裕顕, 末木啓介, 辻英樹, 宮津進, 岡田往子, 栗原モモ, Sandor Tarjan, 松波寿弥, 内田滋夫
    分析化学, 66, 4, 299, 307, JAPAN SOC ANALYTICAL CHEMISTRY, 2017年04月, [査読有り]
    日本語, 研究論文(学術雑誌), A large amount of radiocesium was released from the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company. The determination of dissolved and particulate radiocesium concentrations in water is important, which can be used as basic information for understanding the long-term radiocesium dynamics in the environment and the transfer of radiocesium to crops. Conventional quantitative methods include the evaporative concentration to the dryness method and the AMP method. These methods need to concentrate about 20-200 L of water due to the low concentration of the dissolved radiocesium. After the accident, several new methods, such as the Prussian blue filter cartridge method and the solid-phase disk method, have been developed and put to practical use. In this study, we carried out an accuracy evaluation test to assess five methods (i.e., the evaporative concentration to dryness method, the AMP method, the Prussian blue filter cartridge method, the solid-phase disk method, and the ion-change resin method) using 3 types of water samples containing 0.01-1.0 Bq L-1 of dissolved radiocesium. Our results showed that the z-scores of over 80 % of the measured data were within +/- 2 and their CVs in the range of 8-13 %, indicating good reproducibility of these methods.
  • Effect of soil exchangeable potassium content on cesium absorption and partitioning in buckwheat grown in a radioactive cesium-contaminated field
    Katashi Kubo, Shigeto Fujimura, Hiroyuki Kobayashi, Takeshi Ota, Takuro Shinano
    PLANT PRODUCTION SCIENCE, 20, 4, 396, 405, TAYLOR & FRANCIS LTD, 2017年, [査読有り]
    英語, 研究論文(学術雑誌), The effect of soil exchangeable (plant-available) potassium (ExK) content on cesium (Cs) absorption and translocation in buckwheat was evaluated in a field contaminated with radioactive Cs (Cs-134 and Cs-137, RCs) in 2013. The RCs concentration in buckwheat was significantly positively correlated with the naturally occurring stable Cs (Cs-133, SCs) concentration, and was lower at higher soil ExK content. The RCs and SCs were actively absorbed by buckwheat until the flowering stage. The soil ExK content was significantly negatively correlated with soil exchangeable RCs and SCs (ExRCs and ExSCs) concentrations. Greater RCs and SCs absorption by buckwheat in soils with low ExK contents was mainly due to higher soil ExRCs and ExSCs concentrations. Reproductive organs showed the largest differences in SCs concentration between low-ExK and high-ExK plots. The root-shoot and shoot-reproductive organs translocations of SCs markedly decreased with increasing soil ExK content. In the root-shoot and shoot-reproductive organs translocations, the discrimination of SCs and K decreased with decreasing soil ExK content. Our main findings were as follows: (1) because RCs are mainly taken up at the earlier growth stage, potassium should be applied as a basal fertilizer to decrease the RCs concentration in buckwheat; (2) lower soil ExK content led to higher soil ExRCs concentrations, resulting in greater RCs absorption by buckwheat; (3) the high Cs absorption and translocation and weaker discrimination between Cs and K in low ExK content soil may be due to the expression of K transporter(s) with weak discrimination between Cs and K.
  • Effects of cadmium treatment on the uptake and translocation of sulfate in Arabidopsis thaliana.
    Yamaguchi, C, Takimoto, Y, Ohkama-Ohtsu, N, Hokura, A, Shinano, T, Nakamura, T, Suyama, A, Maruyama-Nakanishi, A
    Plant and Cell Physiology, 57, 11, 2353, 2366, OXFORD UNIV PRESS, 2016年11月, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Cadmium (Cd) is a highly toxic and non-essential element for plants, whereas phytochelatins and glutathione are low-molecular-weight sulfur compounds that function as chelators and play important roles in detoxification. Cadmium exposure is known to induce the expression of sulfur-assimilating enzymes and sulfate uptake by roots. However, the molecular mechanism underlying Cd-induced changes remains largely unknown. Accordingly, we analyzed the effects of Cd treatment on the uptake and translocation of sulfate and accumulation of thiols in Arabidopsis thaliana Both wild type (WT) and null mutant (sel1-10 and sel1-18) plants of the sulfate transporter SULTR1;2 exhibited growth inhibition when treated with CdCl2 However, the mutant plants exhibited a lower growth rate and lower Cd accumulation. Cadmium treatment also upregulated the transcription of SULTR1;2 and sulfate uptake activity in WT plants, but not in mutant plants. In addition, the sulfate, phytochelatin and total sulfur contents were preferentially accumulated in the shoots of both WT and mutant plants treated with CdCl2, and sulfur K-edge XANES spectra suggested that sulfate was the main compound responsible for the increased sulfur content in the shoots of CdCl2-treated plants. Our results demonstrate that Cd-induced sulfate uptake depends on SULTR1;2 activity, and that CdCl2 treatment greatly shifts the distribution of sulfate to shoots, increases the sulfate concentration of xylem sap and upregulates the expression of SULTRs involved in root-to-shoot sulfate transport. Therefore, we conclude that root-to-shoot sulfate transport is stimulated by Cd and suggest that the uptake and translocation of sulfate in CdCl2-treated plants are enhanced by demand-driven regulatory networks.
  • The dynamic state of the ionome in roots, nodules, and shoots of soybean under different nitrogen status and at different growth stages
    Qingnan Chu, Toshihiro Watanabe, Takuro Shinano, Takuji Nakamura, Norikuni Oka, Mitsuru Osaki, Zhimin Sha
    JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, 179, 4, 488, 498, WILEY-V C H VERLAG GMBH, 2016年08月, [査読有り]
    英語, 研究論文(学術雑誌), The relative distribution of 22 mineral elements in the roots, nodules and shoots of the soybean (Glycine max L. Merr. cv. Tsurumusume) at R1 (beginning of the flowering stage) and R7 (beginning of the mature stage) was investigated in response to ammonium and manure N treatment. Plants receiving only atmospheric nitrogen served as the negative control. The addition of ammonium sulfate to the soil caused soil acidification, induced Al and Mn toxicities, and significantly reduced the biomass production in roots and nodules. Ca, Mg, Fe, Mn, Cu, and Zn concentrations were significantly higher in shoots, and those of Mo and Co higher in nodules. The addition of manure to the soil significantly enhanced the levels of Sr, Ba, Cr, and Cd in shoots, whereas the concentration of Cs was decreased at R7. Moreover, when the soybean developed from R1 to R7, the levels of essential elements in nodules decreased, whereas those of nonessential elements increased, irrespective of the nitrogen source. Furthermore, the variation in the concentrations of many elements was not consistent for nodules and roots when soybean developed from R1 to R7. The variation of Mn, Zn, B, and Al concentrations was independent of N treatments. However, Ca, Fe, Cu, Mo, and Se levels were affected strongly by N treatments. This study is the first to document the dynamic variation of the soybean ionome in nodules, roots, and shoots from vegetative to reproductive stage of soybean.
  • Mitigation of radioactive contamination from farmland environment and agricultural products.
    Shinano T
    Modern Environmental Science and Engineering, 2, 7, 454, 461, 2016年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • 乾式Cs除去技術の概要と飯舘村蕨平における仮設資材化実証調査委託業務について
    本間健一, 高野博幸, 小林航, 佐々木忠志, 高橋祐司, 信濃卓郎, 八田珠郎, 万福祐造, 碓井次郎
    環境放射能除染学会誌, 4, 2, 165, 172, 2016年06月, [査読有り]
    日本語, 研究論文(学術雑誌)
  • Distribution of minerals in young and mature leaves of different leaf vegetable crops cultivated in a field.               
    Watanabe, T, Maejima, E, Urayama, M, Owadano, M, Yamauchi, A, Okada, R, Shinano, T, Osaki, M
    Open Journal of Plant Science, 1, 1, 5, 9, 2016年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metabolomics approach in soybean               
    Takuji Nakamura, Keiki Okazaki, Noureddine Benkeblia, Jun Wasaki, Toshihiro Watanabe, Hideyuki Matsuura, Hirofumi Uchimiya, Setsuko Komatsu, Takuro Shinano
    Genetics, Genomics, and Breeding of Soybean, 313, 330, CRC Press, 2016年04月19日
    英語, 論文集(書籍)内論文, Profiling plant metabolites is able to serve a new technology for understanding metabolic pathway and it may also help picking up the difference beneath plant phenotypes. CE-MS is one of the suitable tools to analyze a large number of plant metabolites, while GC-MS is also a very powerful especially when focusing on primary metabolites, and LC-MS(/MS) is suitable for the detection of secondary metabolites. Several applications of metabolomics approach by using these analytical tools with fractionation of cellular organelles and extraction procedures are demonstrated in this chapter.
  • Varietal differences in the absorption and partitioning of cadmium in common wheat (Triticum aestivum L.)
    Katashi Kubo, Hiroyuki Kobayashi, Masaya Fujita, Takeshi Ota, Yasuhiro Minamiyama, Yoshiaki Watanabe, Takashi Nakajima, Takuro Shinano
    ENVIRONMENTAL AND EXPERIMENTAL BOTANY, 124, 79, 88, PERGAMON-ELSEVIER SCIENCE LTD, 2016年04月, [査読有り]
    英語, 研究論文(学術雑誌), Low cadmium (Cd) transfer from the soil to edible parts of crop plants is important to minimize toxicity to humans and animals. We previously showed that Cd accumulation in grains differs substantially among varieties of common wheat (Triticum aestivum L.). In this study, we investigated the factors responsible for these differences by comparing the absorption and partitioning of Cd among wheat varieties with distinct grain Cd concentrations. Three varieties with low grain Cd concentrations (low-Cd/G varieties) and one standard variety were cultivated in a field (under natural conditions) and in pots with Cd application at four growth stages (emergence, jointing, flowering, and grain-filling). The Cd concentration and content in the whole plant and grains were determined at the seedling, flowering, grain-filling, and maturity stages in the field experiment. Cd concentration, content, and partitioning in different plant segments were determined at the maturity stage in the pot experiment. In the field experiment, there were significant differences in Cd partitioning to grains between low-Cd/G varieties and the standard variety. Cd application at different growth stages in the pot experiment indicated the remobilization of Cd from shoots to grains and direct transport of Cd from roots to grains. In the pot experiment, lower Cd absorption was detected in low-Cd/G varieties than in the standard variety and the low-Cd/G varieties exhibited differences in Cd sequestration among plant parts, including the root, leaf, lower stem, first internode, rachis, and/or glume. These results suggest that several factors related to Cd absorption and translocation, such as root traits and xylem and phloem transport, affect the accumulation of Cd in grains in common wheat. Understanding and elucidating the contribution of each of these factors might facilitate the development of common wheat varieties with minimal grain Cd accumulation. (C) 2015 Elsevier B.V. All rights reserved.
  • Evaluation of the cause of unexplained radiocaesium contamination of brown rice in Fukushima in 2013 using autoradiography and gamma-ray spectrometer
    Matsunami, H, Murakami, T, Fujiwara, H, Shinano, T
    Scientific Reports, 6, 20386, 20386, 2016年02月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), The Great East Japan Earthquake on 11 March 2011, caused the release of radioactive materials from the Fukushima Daiichi Nuclear Power Plant (FDNPP), contaminating eastern Japan, particularly in part of Fukushima Prefecture. In 2012 and 2014, the radiocaesium concentration in brown rice did not exceed regulatory levels in Minamisoma City, Fukushima. However, in 2013, some radiocaesium concentrations in brown rice exceeded regulatory levels. In this work, autoradiograms showed that high radioactivity was present as contaminated spots on the panicles of rice and in brown rice in 2013. We evaluate the contribution of direct contamination to the radiocaesium concentration in brown rice and discuss the origin of radiocaesium contamination in brown rice using the (134)Cs/(137)Cs radioactivity ratio. Here, we show that the main cause of the unexplained radiocaesium contamination of brown rice in Minamisoma City in 2013 is the adherence of radioactive materials to the rice panicles, and these radioactive materials are associated with reactor units 2 or 3 of FDNPP.
  • Evaluation of the cause of unexplained radiocaesium contamination of brown rice in Fukushima in 2013 using autoradiography and gamma-ray spectrometry
    Hisaya Matsunami, Toshifumi Murakami, Hideshi Fujiwara, Takuro Shinano
    SCIENTIFIC REPORTS, 6, NATURE PUBLISHING GROUP, 2016年02月, [査読有り]
    英語, 研究論文(学術雑誌), The Great East Japan Earthquake on 11 March 2011, caused the release of radioactive materials from the Fukushima Daiichi Nuclear Power Plant (FDNPP), contaminating eastern Japan, particularly in part of Fukushima Prefecture. In 2012 and 2014, the radiocaesium concentration in brown rice did not exceed regulatory levels in Minamisoma City, Fukushima. However, in 2013, some radiocaesium concentrations in brown rice exceeded regulatory levels. In this work, autoradiograms showed that high radioactivity was present as contaminated spots on the panicles of rice and in brown rice in 2013. We evaluate the contribution of direct contamination to the radiocaesium concentration in brown rice and discuss the origin of radiocaesium contamination in brown rice using the Cs-134/Cs-137 radioactivity ratio. Here, we show that the main cause of the unexplained radiocaesium contamination of brown rice in Minamisoma City in 2013 is the adherence of radioactive materials to the rice panicles, and these radioactive materials are associated with reactor units 2 or 3 of FDNPP.
  • GC-MS based metabolite profiling for flavor characterization of Brassica crops grown with different fertilizer application
    Tomohiko Fukuda, Keiki Okazaki, Ayano Watanabe, Takuro Shinano, Norikuni Oka
    METABOLOMICS, 12, 2, SPRINGER, 2016年02月, [査読有り]
    英語, 研究論文(学術雑誌), In order to supply pleasant foods in ordinal dietary, improving crop quality by applying effective growth conditions is a desirable but challenging approach. In this study, to determine the sensory quality of mizuna (Brassica rapa L. var. Nipposinica), one of a Brassica leafy crops grown with different fertilizer application, GC-MS based hydrophilic metabolites and volatiles as well as sensory attributes were measured. Clusters of applied fertilizer condition were significantly divided between with or without manure amendments within all the variances including sensory and metabolite data. Projection to latent structures regression analyzes revealed that L-glutamine, L-asparagine, and other amino acids negatively correlated with bitterness, whereas raffinose, maltose, and malic acid positively correlated with bitterness. Furthermore glucosinolate breakdown products, particularly allyl isothiocyanate revealed a strong positive correlation with Brassica specific wasabi-like sharpness. Based on the comprehensive view of both metabolite and sensory profiling, the perspective for improvement in sensory quality is discussed.
  • GC-MS based metabolite profiling for flavor characterization of Brassica crops grown with different fertilizer application
    Tomohiko Fukuda, Keiki Okazaki, Ayano Watanabe, Takuro Shinano, Norikuni Oka
    METABOLOMICS, 12, 2, 1, 9, SPRINGER, 2016年02月, [査読有り]
    英語, 研究論文(学術雑誌), In order to supply pleasant foods in ordinal dietary, improving crop quality by applying effective growth conditions is a desirable but challenging approach. In this study, to determine the sensory quality of mizuna (Brassica rapa L. var. Nipposinica), one of a Brassica leafy crops grown with different fertilizer application, GC-MS based hydrophilic metabolites and volatiles as well as sensory attributes were measured. Clusters of applied fertilizer condition were significantly divided between with or without manure amendments within all the variances including sensory and metabolite data. Projection to latent structures regression analyzes revealed that L-glutamine, L-asparagine, and other amino acids negatively correlated with bitterness, whereas raffinose, maltose, and malic acid positively correlated with bitterness. Furthermore glucosinolate breakdown products, particularly allyl isothiocyanate revealed a strong positive correlation with Brassica specific wasabi-like sharpness. Based on the comprehensive view of both metabolite and sensory profiling, the perspective for improvement in sensory quality is discussed.
  • Varietal difference in radiocesium uptake and transfer from radiocesium deposited soils in the genus Amaranthus (vol 60, pg 809, 2014)
    Takuro Shinano, Toshihiro Watanabe, Qingnan Chu
    SOIL SCIENCE AND PLANT NUTRITION, 62, 5-6, 569, 569, TAYLOR & FRANCIS LTD, 2016年, [査読有り]
    英語
  • The ionomic study of vegetable crops.
    Watanabe, T, Maejima, E, Yoshimura, T, Urayama, M, Yamauchi, A, Owadano, M, Okada, R, Osaki, M, Kanayama, Y, Shinano, T
    PLos ONE, 11, 8, e0160273, PUBLIC LIBRARY SCIENCE, 2016年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Soil contains various essential and nonessential elements, all of which can be absorbed by plants. Plant ionomics is the study of the accumulation of these elements (the ionome) in plants. The ionomic profile of a plant is affected by various factors, including species, variety, organ, and environment. In this study, we cultivated various vegetable crop species and cultivars under the same field conditions and analyzed the level of accumulation of each element in the edible and nonedible parts using ionomic techniques. The concentration of each element in the edible parts differed between species, which could be partly explained by differences in the types of edible organs (root, leaf, seed, and fruit). For example, the calcium concentration was lower in seeds and fruit than in other organs because of the higher dependency of calcium accumulation on xylem transfer. The concentration of several essential microelements and nonessential elements in the edible parts also varied greatly between cultivars of the same species, knowledge of which will help in the breeding of vegetables that are biofortified or contain lower concentrations of toxic elements. Comparison of the ionomes of the fruit and leaves of tomato (Solanum lycopersicum) and eggplant (S. melongena) indicated that cadmium and boron had higher levels of accumulation in eggplant fruit, likely because of their effective transport in the phloem. We also found that homologous elements that have been reported to share the same uptake/transport system often showed significant correlation only in a few families and that the slopes of these relationships differed between families. Therefore, these differences in the characteristics of mineral accumulation are likely to affect the ionomic profiles of different families.
  • Decreasing radioactive cesium in lodged buckwheat grain after harvest
    Katashi Kubo, Hiroyuki Kobayashi, Kazutoshi Nemoto, Takashi Hirayama, Hisaya Matsunami, Yasuhiro Ichihashi, Takeshi Ota, Shoji Keitoku, Takuro Shinano
    PLANT PRODUCTION SCIENCE, 19, 1, 91, 95, TAYLOR & FRANCIS LTD, 2016年, [査読有り]
    英語, 研究論文(学術雑誌), This study assessed soil contamination with high radioactive cesium (R-Cs) concentration in buckwheat grains by lodging, and assessed the possibility of R-Cs reduction in grain through post-harvest preparation. Analysis of buckwheat grain produced in farmers' fields and reports from farmers indicated that grain from fields that had lodging showed higher R-Cs than grain from fields with no lodging. A field experiment demonstrated that R-Cs in grain after threshing and winnowing (TW) was about six times higher in lodged plants than in nonlodged plants. In lodged plants, R-Cs in grain was decreased to about one-fourth by polishing, and was decreased to about one-seventh by ultrasonic cleaning, compared with R-Cs in grain after TW. These results demonstrate that R-Cs of buckwheat grain of lodged plants can be decreased by removing soil from the grain surface by polishing and winnowing.
  • Application of ionomics to plant and soil in fields under long-term fertilizer trials
    Toshihiro Watanabe, Masaru Urayama, Takuro Shinano, Ryosuke Okada, Mitsuru Osaki
    SPRINGERPLUS, 4, SPRINGER INTERNATIONAL PUBLISHING AG, 2015年12月, [査読有り]
    英語, 研究論文(学術雑誌), Ionomics is the study of elemental accumulation in living organisms using high-throughput elemental profiling. In the present study, we examined the ionomic responses to nutrient deficiency in maize grown in the field in long-term fertilizer trials. Furthermore, the available elements in the field soils were analyzed to investigate their changes under long-term fertilizer treatment and the ionomic relationships between plant and soil. Maize was cultivated in a field with the following five long-term fertilizer treatments: complete fertilization, fertilization without nitrogen, without phosphorus, without potassium, and no fertilization. Concentrations of 22 elements in leaves at an early flowering stage and in soils after harvest were determined. The fertilizer treatments changed the availabilities of many elements in soils. For example, available cesium was decreased by 39 % and increased by 126 % by fertilizations without nitrogen and potassium, respectively. Effects of treatments on the ionome in leaves were evaluated using the translocation ratio (the concentration in leaves relative to the available concentration in soils) for each element. Nitrogen deficiency specifically increased the uptake ability of molybdenum, which might induce the enhancement of nitrogen assimilation and/or endophytic nitrogen fixation in plant. Potassium deficiency drastically enhanced the uptake ability of various cationic elements. These elements might act as alternatives to K in osmoregulation and counterion of organic/inorganic anions. Two major groups of elements were detected by multivariate analyses of plant ionome. Elements in the same group may be linked more or less in uptake and/or translocation systems. No significant correlation between plant and soil was found in concentrations of many elements, even though various soil extraction methods were applied, implying that the interactions between the target and other elements in soil must be considered when analyzing mineral dynamics between plant and soil.
  • Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice
    Eguchi Tetsuya, Ohta Takeshi, Ishikawa Tetsuya, Matsunami Hisaya, Takahashi Yoshihiko, Kubo Katashi, Yamaguchi Noriko, Kihou Nobuharu, Shinano Takuro
    JOURNAL OF ENVIRONMENTAL RADIOACTIVITY, 147, 33, 42, 2015年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ((137)Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the (137)Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice.
  • Interactions between Cs, Sr, and other nutrients and trace element accumulation in Amaranthus shoot in response to variety effect.
    Chu Q, Watanabe T, Sha Z, Osaki M, Shinano T
    Journal of Agricultural and Food Chemistry, 63, 8, 2355, 63, 2015年03月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Aiming at clarifying the interactions between Cs, Sr, and other mineral elements in the genus Amaranthus, this study adopted 33 different varieties of Amaranthus and investigated the concentrations of 23 mineral elements in shoots grown in the fields of Iino in Fukushima prefecture. Significant varietal effects were detected for all elements except Se, and degree of interspecies variation was highly element dependent. Among 23 elements, amaranths were less sensitive to the accumulation of Cs and Sr than most other mineral elements to the species level. There are six elements showing significant correlation with Cs, positive correlations between As, Rb, Al, Fe, Ni, and Cs, and negative correlation between Ba and Cs. Significant correlations between Ca, Mg, Mn, Zn, B, Ba, Cd, and Sr were detected, and all of the coefficients were positive. Cs and Sr did not present significant correlation, but they were both significantly correlated with Ba. By principal component analysis (PCA), the first and second principal components (PC1 and PC2) accounted for 23.2 and 20.3% of the total variance and associated with Cs and Sr, respectively. Both of the two species took up more Cs by promoting the influx of elements positively correlated with Cs into shoot, but at the same time, Amaranthus hypochondriacus (L.) Mapes 847 decreased the K and Ba uptake and Amaranthus powellii (S. Wats) subsp. Powellii inhibited the accumulation of Rb, Sr, and significantly correlated elements of Sr in shoot. This study is the first to pave the way for comprehension on ionome in amaranth shoot at the variety level. The results of this research provide the ionomic basis for implementing countermeasures in the field against the translocation of Cs (and potentially Sr) toward crops and food.
  • Interactions between Cs, Sr, and Other Nutrients and Trace Element Accumulation in Amaranthus Shoot in Response to Variety Effect
    Qingnan Chu, Toshihiro Watanabe, Zhimin Sha, Mitsuru Osaki, Takuro Shinano
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 63, 8, 2355, 2363, AMER CHEMICAL SOC, 2015年03月, [査読有り]
    英語, 研究論文(学術雑誌), Aiming at clarifying the interactions between Cs, Sr, and other mineral elements in the genus Amaranthus, this study adopted 33 different varieties of Amaranthus and investigated the concentrations of 23 mineral elements in shoots grown in the fields of Iino in Fukushima prefecture. Significant varietal effects were detected for all elements except Se, and degree of interspecies variation was highly element dependent. Among 23 elements, amaranths were less sensitive to the accumulation of Cs and Sr than most other mineral elements to the species level. There are six elements showing significant correlation with Cs, positive correlations between As, Rb, Al, Fe, Ni, and Cs, and negative correlation between Ba and Cs. Significant correlations between Ca, Mg, Mn, Zn, B, Ba, Cd, and Sr were detected, and all of the coefficients were positive. Cs and Sr did not present significant correlation, but they were both significantly correlated with Ba. By principal component analysis (PCA), the first and second principal components (PC1 and PC2) accounted for 23.2 and 20.3% of the total variance and associated with Cs and Sr, respectively. Both of the two species took up more Cs by promoting the influx of elements positively correlated with Cs into shoot, but at the same time, Amaranthus hypochondriacus (L.) Mapes 847 decreased the K and Ba uptake and Amaranthus powellii (S. Wats) subsp. Powellii inhibited the accumulation of Rb, Sr, and significantly correlated elements of Sr in shoot. This study is the first to pave the way for comprehension on ionome in amaranth shoot at the variety level. The results of this research provide the ionomic basis for implementing countermeasures in the field against the translocation of Cs (and potentially Sr) toward crops and food.
  • Analyses and countermeasures for decreasing radioactive cesium in buckwheat in areas affected by the nuclear accident in 2011
    Katashi Kubo, Kazutoshi Nemoto, Hiroyuki Kobayashi, Yasushi Kuriyama, Hirohide Harada, Hisaya Matsunami, Tetsuya Eguchi, Nobuharu Kihou, Takeshi Ota, Shoji Keitoku, Takeshi Kimura, Takuro Shinano
    FIELD CROPS RESEARCH, 170, 40, 46, ELSEVIER SCIENCE BV, 2015年01月, [査読有り]
    英語, 研究論文(学術雑誌), Tokyo Electric Power Company's Fukushima Dai-ichi nuclear power plant released radioactive cesium (Cs) into the environment after the Great East Japan Earthquake of March 11, 2011. After radioactive Cs fell onto agricultural fields, radioactive nuclide levels in some buckwheat (Fagopyrum esculentum Wench) grain subsequently exceeded new standard limits for radioactive materials, including that for radioactive Cs (100 Bq kg(-1)) established by the Japanese government in 2012. A survey of soils and buckwheat grain from 68 farmers' fields in 2012 revealed that soil exchangeable potassium (K) concentration was significantly and negatively correlated with radioactive Cs concentration in the grain. The effect of K application on the reduction of radioactive Cs concentration in the grain was confirmed by pot and field experiments conducted respectively in 2012 and 2013. This effect might result from the similarity of ion forms of K and Cs and/or the lower exchangeable Cs concentrations at higher exchangeable K concentrations in soil. Based on these results, farmers were recommended to establish a soil exchangeable K concentration of 250 mg kg(-1) (300 mg kg(-1) in K2O) before applying basal fertilizer. After this recommendation, the soil K concentrations of farmers' fields increased, causing an overall decrease in radioactive Cs concentrations of buckwheat grain produced in 2013. Consequently, no grain sample from this year exceeded the standard limits for radioactive Cs level across the affected area in Japan. These efforts contributed greatly to the rehabilitation and reconstruction of agriculture in the area contaminated with radioactive Cs. (C) 2014 Elsevier B.V. All rights reserved.
  • Bacterial community shifts associated with high abundance of Rhizobium spp. in potato roots under macronutrient-deficient conditions
    Yusuke Unno, Takuro Shinano, Kiwamu Minamisawa, Seishi Ikeda
    SOIL BIOLOGY & BIOCHEMISTRY, 80, 232, 236, PERGAMON-ELSEVIER SCIENCE LTD, 2015年01月, [査読有り]
    英語, 研究論文(学術雑誌), We evaluated the impacts of a macronutrient deficiency on the community structure of root-associated bacteria in potato (Solanum tuberosum) cultivation. Potato plants were cultivated in a long-term experimental field under a nitrogen, phosphorus, or potassium deficiency, and roots were sampled at the early flowering stage. Amplicon libraries of 16S rRNA gene were constructed for root-associated bacteria, and bacterial diversity was analyzed by Means of pyrosequencing. Statistical analyses showed significantly lower species evenness in the nutrient-deficient plots compared with the value in a plot with standard fertilization. Phylogenetic analyses revealed that the abundance of Rhizobium spp. increased dramatically in all plots under a macronutrient deficiency. (C) 2014 Elsevier Ltd. All rights reserved.
  • ゲル化法を用いた懸濁物質を含む農業関連水試料中の放射性セシウムの定量
    松波寿弥, 申文浩, 高橋義彦, 北島枝織, 土屋貴史, 信濃卓郎
    Radioisotopes, 64, 681, 686, 2015年, [査読有り]
    研究論文(学術雑誌)
  • Application of ionomics to plants and soil in fields under long-term fertilizer trials
    Watanabe T, Urayama M, Shinano T, Okada R, Osaki M
    SpringerPlus, 4, 781, 781, 2015年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Ionomics is the study of elemental accumulation in living organisms using high-throughput elemental profiling. In the present study, we examined the ionomic responses to nutrient deficiency in maize grown in the field in long-term fertilizer trials. Furthermore, the available elements in the field soils were analyzed to investigate their changes under long-term fertilizer treatment and the ionomic relationships between plant and soil. Maize was cultivated in a field with the following five long-term fertilizer treatments: complete fertilization, fertilization without nitrogen, without phosphorus, without potassium, and no fertilization. Concentrations of 22 elements in leaves at an early flowering stage and in soils after harvest were determined. The fertilizer treatments changed the availabilities of many elements in soils. For example, available cesium was decreased by 39 % and increased by 126 % by fertilizations without nitrogen and potassium, respectively. Effects of treatments on the ionome in leaves were evaluated using the translocation ratio (the concentration in leaves relative to the available concentration in soils) for each element. Nitrogen deficiency specifically increased the uptake ability of molybdenum, which might induce the enhancement of nitrogen assimilation and/or endophytic nitrogen fixation in plant. Potassium deficiency drastically enhanced the uptake ability of various cationic elements. These elements might act as alternatives to K in osmoregulation and counterion of organic/inorganic anions. Two major groups of elements were detected by multivariate analyses of plant ionome. Elements in the same group may be linked more or less in uptake and/or translocation systems. No significant correlation between plant and soil was found in concentrations of many elements, even though various soil extraction methods were applied, implying that the interactions between the target and other elements in soil must be considered when analyzing mineral dynamics between plant and soil.
  • 農産物への放射性セシウムの移行抑制対策               
    信濃卓郎
    JATAFF, 3, 9, 24, 29, 2015年, [招待有り]
    研究論文(学術雑誌)
  • パネルディスカッション〜福島の再生と科学技術コミュニケーション〜
    早岡英介, 久保田直, 信濃卓郎, 本田紀生
    科学技術コミュニケーション, 17, 17, 99, 112, 北海道大学高等教育推進機構 高等教育研究部 科学技術コミュニケーション教育研究部門(CoSTEP), 2015年, [査読有り], [招待有り]
    日本語, 研究論文(学術雑誌)
  • 農業再建への研究者としての取り組み
    信濃卓郎
    科学技術コミュニケーション, 17, 17, 85, 91, 2015年, [査読有り], [招待有り]
  • Baceterial community shifts associated with high abundance of Rhizobium sp. in potato roots under deficient conditions of macro fertilizer elements
    Unno Y, Shinano T, Minamisawa K, Ikeda S
    Soil Biology and Biochemistry, 80, 232, 236, 2015年
    英語, 研究論文(学術雑誌)
  • Varietal difference in radiocesium uptake and transfer from radiocesium deposited soils in the genus Amaranthus
    Takuro Shinano, Toshihiro Watanabe, Qingnan Chu, Mitsuru Osaki, Daisuke Kobayashi, Toshiyasu Okouchi, Hisaya Matsunami, Osamu Nagata, Keiki Okazaki, Takuji Nakamura
    SOIL SCIENCE AND PLANT NUTRITION, 60, 6, 809, 817, TAYLOR & FRANCIS LTD, 2014年11月, [査読有り]
    英語, 研究論文(学術雑誌), Within Amaranthaceae, 33 different varieties, including local varieties from Japan, were grown in 2012 in a field in the town of Iino in the Fukushima prefecture, which is located approximately 51km north of Tokyo Electric Power Company, Fukushima Daiichi Nuclear Power Plant (FDNPP). The contamination level of the soil was 2770 +/- 140Bq kg(-1) dry weight ((134)Cesium (Cs)+Cs-137, average +/- SE), and the field was also cultivated in 2011. There was a significant varietal difference in the dry weight production, radiocesium accumulation and transfer factor (TF) of radiocesium from the soil to the plant. The ratio of the lowest TF to the highest TF was approximately 3. Because the ratio of Cs-137 to Cs-133 was significantly positive, radiocesium seems to be absorbed in a manner similar to that of Cs-133. It is suggested that the varietal difference in the behavior of radiocesium uptake mainly depends on its genetic background rather than on environmental factors.
  • Metabolite profiling of soybean root exudates under phosphorus deficiency
    Keitaro Tawaraya, Ryota Horie, Takuro Shinano, Tadao Wagatsuma, Kazuki Saito, Akira Oikawa
    SOIL SCIENCE AND PLANT NUTRITION, 60, 5, 679, 694, TAYLOR & FRANCIS LTD, 2014年09月, [査読有り]
    英語, 研究論文(学術雑誌), Root exudates are derived from plant metabolites and their composition is affected by the plant nutritional status. The purpose of this study was to examine soybean root exudates under phosphorus (P) deficiency using a metabolite profiling technique. Glycine max L. (cv. Suzuyutaka) was grown in a culture solution at P concentrations of 0 (P0) and 8 (P8) mg P L-1 for 1, 5, 10 and 15days after transplanting. Shoot extract, root extract and root exudates were collected and their metabolites were determined by capillary electrophoresis/time-of-flight mass spectrometry (CE-TOF MS). The shoot P concentration and dry weight of soybean plants grown at P0 were lower than those at P8. One hundred and eight, 116 and 79 metabolites were identified in the shoot extract, root extract and root exudates, respectively. The concentrations of several metabolites including amino acids and organic acids in root exudates were higher at P0 than at P8, irrespective of the P concentration in the shoot or root extract. These findings suggest that soybean roots actively release metabolites in response to P deficiency.
  • Arsenic alters uptake and distribution of sulphur in Pteris vittata.
    Toshihiro Watanabe, Ran Kouho, Tomo Katayose, Nobuyuki Kitajima, Naoya Sakamoto, Noriko Yamaguchi, Takuro Shinano, Hisayoshi Yurimoto, Mitsuru Osaki
    Plant, cell & environment, 37, 1, 45, 53, 1, 2014年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Low-molecular-weight thiol (LMWT) synthesis has been reported to be directly induced by arsenic (As) in Pteris vittata, an As hyperaccumulator. Sulphur (S) is a critical component of LMWTs. Here, the effect of As treatment on the uptake and distribution of S in P. vittata was investigated. In P. vittata grown under low S conditions, the presence of As in the growth medium enhanced the uptake of SO4(2-), which was used for LMWT synthesis in fronds. In contrast, As application did not affect SO4(2-) uptake in Nephrolepis exaltata, an As non-hyperaccumulator. Moreover, the isotope microscope system revealed that S absorbed with As accumulated locally in a vacuole-like organelle in epidermal cells, whereas S absorbed alone was distributed uniformly. These results suggest that S is involved in As transport and/or accumulation in P. vittata. X-ray absorption near-edge structure analysis revealed that the major As species in the fronds and roots of P. vittata were inorganic As(III) and As(V), respectively, and that As-LMWT complexes occurred as a minor species. Consequently, in case of As accumulation in P. vittata, S possibly acts as a temporary ligand for As in the form of LMWTs in intercellular and/or intracellular transport (e.g. vacuolar sequestration).
  • Verification of radiocesium decontamination from farmlands by plants in Fukushima.
    Kobayashi D, Okouchi T, Yamagami M, Shinano T
    Journal of plant research, 127, 1, 51, 6, 1, 2014年, [査読有り], [国内誌]
    英語, The purpose of this study was to verify radiocesium decontamination from Fukushima farmland by plants and to screen plants useful for phytoremediation. Thirteen species from three families (Asteraceae, Fabaceae, and Poaceae) of crops were grown in shallow and deeply cultivated fields (0-8 and 0-15 cm plowing, respectively). To change plowing depth was expected to make different contacting zone between root system and radiocesium in soil. The radioactivity values of the plants due to the radiocesium ¹³⁴Cs and ¹³⁷Cs were 22-179 and 29-225 Bq kg dry weight⁻¹, respectively. The ¹³⁴Cs and ¹³⁷Cs transfer factors for plants grown in the shallow field ranged from 0.021 to 0.12 and fro 0.019 to 0.13, respectively, with the geometric means of 0.051 and 0.057, respectively. The ¹³⁴Cs and ¹³⁷Cs transfer factors for plants grown in the deep field ranged from 0.019 to 0.13 and from 0.022 to 0.13, respectively, with the geometric means of 0.045 and 0.063, respectively. Although a reducing ratio was calculated to evaluate the decrease in radiocesium from contaminated soil during cultivation (i.e., phytoremediation ability), no plant species resulted in a remarkable decrease in radiocesium in soil among the tested crops. These results should be followed up for several years and further analyses are required to evaluate whether the phytoremediation technique is applicable to radioactively contaminated farmlands.
  • Effect of phosphorus levels on the protein profiles of secreted protein and root surface protein of rice.
    Shinano T, Yoshimura T, Watanabe T, Unno Y, Osaki M, Nanjo Y, Komatsu S
    Journal of proteome research, 12, 11, 4748, 56, 11, 2013年11月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Plant roots are complicated organs that absorb water and nutrients from the soil. Roots also play an essential role in protecting plants from attack by soil pathogens and develop a beneficial role with some soil microorganisms. Plant-derived rhizosphere proteins (e.g., root secretory proteins and root surface binding proteins) are considered to play important roles in developing mutual relationships in the rhizosphere. In the rhizosphere, where plant roots meet the surrounding environment, it has been suggested that root secretory protein and root surface binding protein are important factors. Furthermore, it is not known how the physiological status of the plant affects the profile of these proteins. In this study, rice plants were grown aseptically, with or without phosphorus nutrition, and proteins were obtained from root bathing solution (designated as root secretory proteins) and obtained using 0.2 M CaCl2 solution (designated as root surface binding proteins). The total number of identified proteins in the root bathing solution was 458, and the number of root surface binding proteins was 256. More than half of the proteins were observed in both fractions. Most of the proteins were categorized as either having signal peptides or no membrane transport helix sites. The functional categorization suggested that most of the proteins seemed to have secretory pathways and were involved in defense/disease-related functions. These characteristics seem to be unique to rhizosphere proteins, and the latter might be part of the plants strategy to defeat pathogens in the soil. The low phosphorus treatment significantly increased the number of pathogenesis-related proteins in the root secretory proteins, whereas the change was small in the case of the root surface binding proteins. The results suggested that the roots are actively and selectively secreting protein into the rhizosphere.
  • Aroma characteristic and volatile profiling of carrot varieties and quantitative role of terpenoid compounds for carrot sensory attributes.
    Fukuda T, Okazaki K, Shinano T
    Journal of food science, 78, 11, S1800-6, 6, 11, 2013年11月, [査読有り], [国際誌]
    英語, The aroma characteristics and volatile profiles of 14 carrot varieties were investigated by sensory evaluations and gas chromatography-mass spectrometry volatile analyses. The sensory map obtained by principal components analysis showed that the sensory attributes comprised 3 categories: sour/green, overall carrot/harsh/ink-like, and fruity/fresh/sweet. The Kuroda type is characterized by lower intensities of overall carrot/harsh/ink-like and fruity/fresh/sweet notes. Furthermore, volatile profiling indicated that this type did not have significantly higher amounts of volatiles. Partial least squares regression analysis determined the quantitative contributions to ink-like, harsh, and fruity carrot aromas; monoterpenes had significant positive correlations with these attributes, while bisabolene isomers had negative correlations. The aroma attribute intensity and contents of volatiles and nutritional compounds are relatively low in the Kuroda type than in other carrot types. This type may be useful for reducing carrot harshness during the development of new carrots with good eating qualities.
  • Mitigation of peroxidative stress for barley exposed to cadmium in the presence of water-extractable organic matter from compost-like materials.
    Tachibana N, Nagasawa K, Wang B, Nishiya K, Fukushima M, Kanno H, Shinano T, Okazaki K
    Chemosphere, 93, 4, 695, 700, 4, 2013年10月, [査読有り], [国際誌]
    英語, The effects of water-extractable organic matter (WEOM) from compost-like materials on peroxidative stress were investigated for hydroponic culture of barley exposed to Cd. In the presence of WEOM, lipoxygenase activity and malondialdehyde, indices of peroxidative stress in barley, were significantly reduced, compared to those with Cd alone (5 μM) for a 30-d culture (p<0.05). In addition, Cd uptake in the presence of WEOM samples was significantly lower than that in their absence (p<0.05). These results indicate that the addition of WEOM can be effective in mitigating the peroxidative stress in barley exposed to Cd. Of the total Cd in the solution, 7-8% was complexed with WEOM, indicating that the complexation of Cd with WEOM is a minor factor in reducing Cd-induced stress in barley. The WEOM sample was purified by cation-exchange column and ultrafiltration to remove the nutrient minerals, such as Ca, Mg and Fe. When the purified WEOM was employed for hydroponic culture in the presence of Cd, significant decreases in peroxidative stress and Cd uptake were observed (p<0.05). These results show that the organic components in WEOM contribute to the mitigation of peroxidative stress in barley exposed to Cd.
  • Metabolite Profiling of Mizuna (Brassica rapa L. var. Nipponsinica) To Evaluate the Effects of Organic Matter Amendments
    Ayano Watanabe, Keiki Okazaki, Toshihiro Watanabe, Mitsuru Osaki, Takuro Shinano
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 61, 5, 1009, 1016, AMER CHEMICAL SOC, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌), Organic matter amendment is an essential agricultural protocol to improve soil function and carbon sequestration. However, the effect of organic matter amendments on crop quality has not been well-defined. This study applied gas chromatography mass spectrometry to investigate the metabolite profiling of mizuna (Brassica rapa L. var. Nipponsinica) with different organic matter amendments with respect to quality and quantity. Principal component analysis showed that 33.4, 15.6, and 6.6% of the total variance was attributable to the plant N concentration, fast-release organic fertilizer (fish cake), chicken droppings), and rapeseed cake), and manure application (fresh and dried), respectively. The peak areas of 18 and 15 compounds were significantly altered under organic fertilizer and manure amendment, respectively, compared with pure chemical fertilizer amendment. The compounds altered with manure amendment were similar to those reported in previous studies using other species. This study is the first to show dear metabolic alterations in plants through the amendment of fast-release organic fertilizer. Mizuna is a unique plant species that responds to both organic fertilizer and manure. These observations are useful to clarify the effect of organic matter amendment and quality control in farming systems using organic matter.
  • Metagenomic analysis of the rhizosphere soil microbiome with respect to phytic acid utilization
    Yusuke Unno, Takuro Shinano
    Microbes and Environments, 28, 1, 120, 127, 1, 2013年, [査読有り]
    英語, 研究論文(学術雑誌), While phytic acid is a major form of organic phosphate in many soils, plant utilization of phytic acid is normally limited
    however, culture trials of Lotus japonicus using experimental field soil that had been managed without phosphate fertilizer for over 90 years showed significant usage of phytic acid applied to soil for growth and flowering and differences in the degree of growth, even in the same culture pot. To understand the key metabolic processes involved in soil phytic acid utilization, we analyzed rhizosphere soil microbial communities using molecular ecological approaches. Although molecular fingerprint analysis revealed changes in the rhizosphere soil microbial communities from bulk soil microbial community, no clear relationship between the microbiome composition and flowering status that might be related to phytic acid utilization of L. japonicus could be determined. However, metagenomic analysis revealed changes in the relative abundance of the classes Bacteroidetes, Betaproteobacteria, Chlorobi, Dehalococcoidetes and Methanobacteria, which include strains that potentially promote plant growth and phytic acid utilization, and some gene clusters relating to phytic acid utilization, such as alkaline phosphatase and citrate synthase, with the phytic acid utilization status of the plant. This study highlights phylogenetic and metabolic features of the microbial community of the L. japonicus rhizosphere and provides a basic understanding of how rhizosphere microbial communities affect the phytic acid status in soil.
  • METABOLITE PROFILING OF SHOOT EXTRACTS, ROOT EXTRACTS, AND ROOT EXUDATES OF RICE PLANT UNDER PHOSPHORUS DEFICIENCY
    Keitaro Tawaraya, Ryota Horie, Akiko Saito, Takuro Shinano, Tadao Wagatsuma, Kazuki Saito, Akira Oikawa
    JOURNAL OF PLANT NUTRITION, 36, 7, 1138, 1159, TAYLOR & FRANCIS INC, 2013年01月, [査読有り]
    英語, 研究論文(学術雑誌), We applied a metabolite profiling technique to investigate root exudates under phosphorus (P) deficiency. Oryza sativa was grown in culture solution containing three P levels (0, 1, and 8mg P L-1). Shoot extracts, root extracts, and root exudates were obtained from 18 and 23-day-old plants and their metabolites were determined by capillary electrophoresis/time-of-flight mass spectrometry. Eighty, 90, and 65 metabolites were identified in shoot extracts, root extracts, and root exudates, respectively. Sixty-three to eighty-four percent of the metabolites were exuded to the rhizosphere. More than 33% of the metabolites in the root exudates showed higher concentration at low P than at high P. On the other hand, only 14% of the metabolites in the root extracts showed lower concentration at low P than at high P. These results suggest that rice roots actively release many metabolites in response to P deficiency.
  • Ionome of Soybean Seed Affected by Previous Cropping with Mycorrhizal Plant and Manure Application
    Zhimin Sha, Norikuni Oka, Toshihiro Watanabe, Biatna Dulbert Tampubolon, Keiki Okazaki, Mitsuru Osaki, Takuro Shinano
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 60, 38, 9543, 9552, AMER CHEMICAL SOC, 2012年09月, [査読有り]
    英語, 研究論文(学術雑誌), Two field experiments were conducted to investigate the effects of previous cultivation of an arbuscular mycorrhizal (AM) host plant and manure application on the concentration of 19 mineral elements in soybean (Glycine max L. Merr. cv. Tsurumusume) seeds. Each experiment ran for two years (experiment 1 took place in 2007-2008, and experiment 2 took place in 2008-2009) with a split plot design. Soybeans were cultivated after growing either an AM host plant (maize, Zea mays L. cv. New dental) or a non-AM host plant (buckwheat, Fagopyrum esculentum Moench. cv. Kitawase-soba) in the first year in the main plots, with manure application (0 and 20 t/ha) during the soybean season in split plots from both main plots. On the basis of the two experiments, manure application significantly increased the available potassium (K) and decreased the available iron (Fe) and cesium (Cs) in the soil. However, higher concentrations of cadmium (Cd) and barium (Ba) and lower concentrations of Cs in the seed were induced by the application of manure. Cd levels in the seed were decreased by prior cultivation with the AM host plant. The present study showed that the identity of the prior crop and manure application changed the mineral contents of the soybean seed and suggests a connection between environmental factors and food safety.
  • Mitigation of peroxidative stress for a barley exposed to cadmium in the presence of water-extractable organic matter from compost-like materials.               
    Naoya Tachibana, Kenya Nagasawa, Masami Fukushima, Hikari Kanno, Takuro Shinano, Keiki Okazaki
    In: “Functions of Natural Organic Matter in Changing Environment” Proceeding Papers of The 16th Meeting of the International Humic Substances Society, 347, 349, 2012年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス)
  • A rapid and simple PCR method for identifying isolates of the genus Azospirillum within populations of rhizosphere bacteria
    A. Shime-Hattori, S. Kobayashi, S. Ikeda, R. Asano, H. Shime, T. Shinano
    JOURNAL OF APPLIED MICROBIOLOGY, 111, 4, 915, 924, WILEY-BLACKWELL, 2011年10月, [査読有り]
    英語, 研究論文(学術雑誌), Aims: To develop a rapid and simple genus-specific polymerase chain reaction (PCR) method for detecting and identifying isolates of the genus Azospirillum which is well-recognized as plant growth-promoting rhizobacterium.
    Methods and Results: Nine pairs of PCR primers were designed based on the Azospirillum 16S rRNA, ipdC, nifA and nifH genes to assess their genus specificity by testing against 12 Azospirillum (from seven species) and 15 non-Azospirillum reference strains, as compared with the fAZO/rAZO pair reported by Baudoin et al. (J Appl Microbiol, 108, 2010, 25). Among the primer pairs assessed, the Az16S-A pair designed on the 16S rRNA gene sequence showed the highest genus specificity: it successfully yielded a single amplicon of the expected size in all the 12 Azospirillum strains and for a close relative, Rhodocista centenaria. The PCR with the Az16S-A primers generated a detectable amount of the amplicon from >= 10(3) CPU ml(-1) of Azospirillum cell suspensions even in the presence of contaminants and accurately discriminated Azospirillum and non-Azospirillum species in both 35 Azospirillum-like and 70 unknown isolates from plant roots and rhizosphere soils.
    Conclusions: We developed a rapid and simple PCR method for detecting and identifying Azospirillum isolates within populations of rhizosphere bacteria.
    Significance and Impact of the Study: The method developed would serve as a useful tool for isolating a variety of indigenous Azospirillum bacteria from agricultural samples.
  • The Genotype of the Calcium/Calmodulin-Dependent Protein Kinase Gene (CCaMK) Determines Bacterial Community Diversity in Rice Roots under Paddy and Upland Field Conditions
    Seishi Ikeda, Takashi Okubo, Naoya Takeda, Mari Banba, Kazuhiro Sasaki, Haruko Imaizumi-Anraku, Shinsuke Fujihara, Yoshinari Ohwaki, Kenshiro Ohshima, Yoshimichi Fukuta, Shima Eda, Hisayuki Mitsui, Masahira Hattori, Tadashi Sato, Takuro Shinano, Kiwamu Minamisawa
    APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 13, 4399, 4405, AMER SOC MICROBIOLOGY, 2011年07月, [査読有り]
    英語, 研究論文(学術雑誌), The effects of the Oryza sativa calcium/calmodulin-dependent protein kinase OsCCaMK genotype (dominant homozygous [D], heterozygous [H], recessive homozygous [R]) on rice root-associated bacteria, including endophytes and epiphytes, were examined by using a Tos17 rice mutant line under paddy and upland field conditions. Roots were sampled at the flowering stage and were subjected to clone library analyses. The relative abundance of Alphaproteobacteria was noticeably decreased in R plants under both paddy and upland conditions (0.8% and 3.0%, respectively) relative to those in D plants (10.3% and 17.4%, respectively). Population shifts of the Sphingomonadales and Rhizobiales were mainly responsible for this low abundance in R plants. The abundance of Anaerolineae (Chloroflexi) and Clostridia (Firmicutes) was increased in R plants under paddy conditions. The abundance of a subpopulation of Actinobacteria (Saccharothrix spp. and unclassified Actinosynnemataceae) was increased in R plants under upland conditions. Principal coordinate analysis revealed unidirectional community shifts in relation to OsCCaMK gene dosage under both conditions. In addition, shoot length, tiller number, and plant weight decreased as the OsCCaMK gene dosage decreased under upland conditions. These results suggest significant impacts of OsCCaMK on both the diversity of root-associated bacteria and rice plant growth under both paddy and upland field conditions.
  • Autoregulation of Nodulation Interferes with Impacts of Nitrogen Fertilization Levels on the Leaf-Associated Bacterial Community in Soybeans
    Seishi Ikeda, Mizue Anda, Shoko Inaba, Shima Eda, Shusei Sato, Kazuhiro Sasaki, Satoshi Tabata, Hisayuki Mitsui, Tadashi Sato, Takuro Shinano, Kiwamu Minamisawa
    APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77, 6, 1973, 1980, AMER SOC MICROBIOLOGY, 2011年03月, [査読有り]
    英語, 研究論文(学術雑誌), The diversities leaf-associated bacteria on nonnodulated (Nod(-)), wild-type nodulated (Nod(+)), and hypernodulated (Nod(+) (+)) soybeans were evaluated by clone library analyses of the 16S rRNA gene. To analyze the impact of nitrogen fertilization on the bacterial leaf community, soybeans were treated with standard nitrogen (SN) (15 kg N ha(-1)) or heavy nitrogen (HN) (615 kg N ha(-1)) fertilization. Under SN fertilization, the relative abundance of Alphaproteobacteria was significantly higher in Nod(-) and Nod(+) (+) soybeans (82% to 96%) than in Nod(+) soybeans (54%). The community structure of leaf-associated bacteria in Nod(+) soybeans was almost unaffected by the levels of nitrogen fertilization. However, differences were visible in Nod(-) and Nod(+) (+) soybeans. HN fertilization drastically decreased the relative abundance of Alphaproteobacteria in Nod(-) and Nod(+) (+) soybeans (46% to 76%) and, conversely, increased those of Gammaproteobacteria and Firmicutes in these mutant soybeans. In the Alphaproteobacteria, cluster analyses identified two operational taxonomic units (OTUs) (Aurantimonas sp. and Methylobacterium sp.) that were especially sensitive to nodulation phenotypes under SN fertilization and to nitrogen fertilization levels. Arbuscular mycorrhizal infection was not observed on the root tissues examined, presumably due to the rotation of paddy and upland fields. These results suggest that a subpopulation of leaf-associated bacteria in wild-type Nod(+) soybeans is controlled in similar ways through the systemic regulation of autoregulation of nodulation, which interferes with the impacts of N levels on the bacterial community of soybean leaves.
  • Proteomic analysis of secreted proteins from aseptically grown rice
    T. Shinano, S. Komatsu, T. Yoshimura, S. Tokutake, F. -J. Kong, T. Watanabe, J. Wasaki, M. Osaki
    PHYTOCHEMISTRY, 72, 4-5, 312, 320, PERGAMON-ELSEVIER SCIENCE LTD, 2011年03月, [査読有り]
    英語, 研究論文(学術雑誌), Plants are known to secrete a variety of compounds into the rhizosphere. These compounds are thought to play important roles in the regulation of soil chemical properties and soil microorganisms. To determine the composition of proteins secreted from rice roots, aseptic hydro culture was performed, and the collected proteins were analyzed. Over 100 proteins were identified; most were identified using the rice database (RAP-DB), and about 60% of the identified proteins were suspected to have a signal peptide. Functional categorization suggested that most were secondary metabolism-and defense-related proteins. Pathogenesis-and stress-related proteins were the major proteins found in the bathing solution under aseptic conditions. Thus, we propose that rice plants constitutively secrete a large variety of proteins to protect their roots against abiotic and/or biotic stresses in the environment. (C) 2010 Elsevier Ltd. All rights reserved.
  • Changes in saccharide, amino acid and S-methylmethionine content during malting of barley grown with different nitrogen and sulfur status
    Masahito Nanamori, Toshihiro Watanabe, Takuro Shinano, Makoto Kihara, Kazumitsu Kawahara, Shinji Yamada, Mitsuru Osaki
    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, 91, 1, 85, 93, JOHN WILEY & SONS LTD, 2011年01月, [査読有り]
    英語, 研究論文(学術雑誌), BACKGROUND: Changes in saccharide, amino acid and S-methylmethionine (SMM) concentrations and enzyme activities during the malting of barley grown with different nitrogen (N) and sulfur (S) supplementation were investigated in order to clarify their relationship with N and S fertiliser levels.
    RESULTS: Concentrations of N and S in barley grain were significantly increased by the addition of N to the culture soil. Application of N decreased the starch concentration in grain. On the other hand, higher N fertilisation increased the beta-glucan concentration in grain and malt, thus decreasing the accessibility of beta-glucanase to its substrates. Proteolytic enzyme activity was significantly higher in the absence (-N treatment) than in the presence (+N treatment) of N fertiliser, making the concentration of the majority of amino acids in malt slightly higher in the -N treatment. SMM was synthesised in grain after imbibition, and application of N increased the SMM content in malt.
    CONCLUSION: Although SMM can be controlled to a certain extent during kilning, a balanced supply of N and S during cultivation can also be helpful for the production of malt with lower SMM concentration. Adequate soil management is desirable to maintain the balance between good agronomic performance and high malt quality. (C) 2010 Society of Chemical Industry
  • Influence of arsenic stress on synthesis and localization of low-molecular-weight thiols in Pteris vittata
    Yuki Sakai, Toshihiro Watanabe, Jun Wasaki, Takeshi Senoura, Takuro Shinano, Mitsuru Osaki
    ENVIRONMENTAL POLLUTION, 158, 12, 3663, 3669, ELSEVIER SCI LTD, 2010年12月, [査読有り]
    英語, 研究論文(学術雑誌), The roles of low-molecular-weight thiols (LMWTs), such as glutathione and phytochelatins, in arsenic (As) tolerance and hyperaccumulation in Pteris vittata an As-hyperaccumulator fern remain to be better understood. This study aimed to thoroughly characterize LMWT synthesis in P. vittata to understand the roles played by LMWTs in As tolerance and hyperaccumulation. LMWT synthesis in P. vittata was induced directly by As, and not by As-mediated oxidative stress. Expression of PvECS2. one of the putative genes of gamma-glutamylcysteine synthetase (gamma ECS), increases in P. vittata shoots at 48 h after the onset of As exposure, almost corresponding to the increase in the concentrations of gamma-glutamylcysteine and glutathione. Furthermore, localization of As showed similar trends to those of LMWTs in fronds at both whole-frond and cellular levels. This study thus indicates the specific contribution of LMWTs to As tolerance in P. vittata. gamma ECS may be responsible for the As-induced enhancement of LMWT synthesis. (C) 2010 Elsevier Ltd. All rights reserved.
  • Analysis of Diversity of Diazotrophic Bacteria Associated with the Rhizosphere of a Tropical Arbor, Melastoma malabathricum L.
    Atsuya Sato, Toshihiro Watanabe, Yusuke Unno, Erry Purnomo, Mitsuru Osaki, Takuro Shinano
    MICROBES AND ENVIRONMENTS, 24, 2, 81, 87, JAPANESE SOC MICROBIAL ECOLOGY, DEPT BIORESOURCE SCIENCE, 2009年, [査読有り]
    英語, 研究論文(学術雑誌), The diversity of diazotrophic bacteria in the rhizosphere of Melastoma malabathricum L. was investigated by cloning-sequencing of the nifH gene directly amplified from DNA extracted from soil. Samples were obtained from the rhizosphere and bulk soil of M. malabathricum growing in three different soil types (acid sulfate, peat and sandy clay soils) located very close to each other in south Kalimantan, Indonesia. Six clone libraries were constructed, generated from bulk and rhizosphere soil samples, and 300 nifH clones were produced, then assembled into 29 operational taxonomic units (OTUs) based on percent identity values. Our results suggested that nifH gene diversity is mainly dependent on soil properties, and did not differ remarkably between the rhizosphere and bulk soil of M. malabathricum except in acid sulfate soil. In acid sulfate soil, as the Shannon diversity index was lower in rhizosphere than in bulk soil, it is suggested that particular bacterial species might accumulate in the rhizosphere.
  • Rapid characterization of plant mutants with an altered ion-profile: a case study using Lotus japonicus
    Zheng Chen, Toshihiro Watanabe, Takuro Shinano, Keiki Okazaki, Mitsuru Osaki
    NEW PHYTOLOGIST, 181, 4, 795, 801, WILEY-BLACKWELL PUBLISHING, INC, 2009年, [査読有り]
    英語, 研究論文(学術雑誌), Legumes are second only to cereals in their importance to humans, and study of their functional genomics of nutrition and other trace elements is crucial for agricultural production and food fortification. We describe here an ionomic screening experiment carried out to investigate the accumulation of 15 elements in shoots of mutants of Lotus japonicus, a good genetic tool for legume study.
    Approximately 2000 mutagenized M2 plants were cultivated in a novel low-cost high-throughput system and their elemental profiles were determined by inductively coupled plasma mass spectroscopy (ICP-MS).
    After triple-checking the element concentrations in M2 or M3 plant shoots, 31 mutants with altered elemental profiles were identified. Surprisingly, the number of genes regulating essential elements was similar to the number regulating nonessential elements. Magnesium (Mg) and nickel (Ni) were correlated in a number of mutants. Further investigation suggested that phosphorus (P) and cobalt (Co) might be involved in the ion homeostasis network of Mg and Ni.
    The results suggested that the pathways for element uptake or translocation were highly linked through the ion transport-related genes. Ionomics proved to be a powerful functional genomics tool for determining genes related to ion homeostasis in this study.
    New Phytologist (2009) 181: 795-801doi: 10.1111/j.1469-8137.2008.02730.x.
  • Sequencing and Analysis of Approximately 40 000 Soybean cDNA Clones from a Full-Length-Enriched cDNA Library
    Taishi Umezawa, Tetsuya Sakurai, Yasushi Totoki, Atsushi Toyoda, Motoaki Seki, Atsushi Ishiwata, Kenji Akiyama, Atsushi Kurotani, Takuhiro Yoshida, Keiichi Mochida, Mie Kasuga, Daisuke Todaka, Kyonoshin Maruyama, Kazuo Nakashima, Akiko Enju, Saho Mizukado, Selina Ahmed, Kyoko Yoshiwara, Kyuya Harada, Yasutaka Tsubokura, Masaki Hayashi, Shusei Sato, Toyoaki Anai, Masao Ishimoto, Hideyuki Funatsuki, Masayoshi Teraishi, Mitsuru Osaki, Takuro Shinano, Ryo Akashi, Yoshiyuki Sakaki, Kazuko Yamaguchi-Shinozaki, Kazuo Shinozaki
    DNA RESEARCH, 15, 6, 333, 346, OXFORD UNIV PRESS, 2008年12月, [査読有り]
    英語, 研究論文(学術雑誌), A large collection of full-length cDNAs is essential for the correct annotation of genomic sequences and for the functional analysis of genes and their products. We obtained a total of 39 936 soybean cDNA clones (GMFL01 and GMFL02 clone sets) in a full-length-enriched cDNA library which was constructed from soybean plants that were grown under various developmental and environmental conditions. Sequencing from 5' and 3' ends of the clones generated 68 661 expressed sequence tags (ESTs). The EST sequences were clustered into 22 674 scaffolds involving 2580 full-length sequences. In addition, we sequenced 4712 full-length cDNAs. After removing overlaps, we obtained 6570 new full-length sequences of soybean cDNAs so far. Our data indicated that 87.7% of the soybean cDNA clones contain complete coding sequences in addition to 5'- and 3'-untranslated regions. All of the obtained data confirmed that our collection of soybean full-length cDNAs covers a wide variety of genes. Comparative analysis between the derived sequences from soybean and Arabidopsis, rice or other legumes data revealed that some specific genes were involved in our collection and a large art of them could be annotated to unknown functions. A large set of soybean full-length cDNA clones reported in this study will serve as a useful resource for gene discovery from soybean and will also aid a precise annotation of the soybean genome.
  • Differences in the metabolite profiles of spinach (Spinacia oleracea L.) leaf in different concentrations of nitrate in the culture solution
    Keiki Okazaki, Norikuni Oka, Takuro Shinano, Mitsuru Osaki, Masako Takebe
    PLANT AND CELL PHYSIOLOGY, 49, 2, 170, 177, OXFORD UNIV PRESS, 2008年02月, [査読有り]
    英語, 研究論文(学術雑誌), The nitrogen (N) status of a plant determines the composition of its major components (amino acids, proteins, carbohydrates and organic acids) and, directly or indirectly, affects the quality of agricultural products in terms of their calorific value and taste. Although these effects are guided by changes in metabolic pathways, no overall metabolic analysis has previously been conducted to demonstrate such effects. Here, metabolite profiling using gas chromatographymass spectrometry (GC-MS) was used to evaluate the effect of N levels on spinach tissue, comparing two cultivars that differed in their ability to use N. Wide variation in N content was observed without any distinct inhibition of growth in either cultivar. Principal component analysis (PCA) and self-organizing mapping (SOM) were undertaken to describe changes in the metabolites of mature spinach leaves. In PCA, the first component accounted for 44.5% of the total variance, the scores of which was positively correlated with the plants N content, and a close relationship between metabolite profiles and N status was observed. Both PCA and SOM revealed that metabolites could be broadly divided into two types, correlating either positively or negatively with plant N content. The simple and co-coordinated metabolic stream, containing both general and spinach-specific aspects of plant N content, will be useful in future research on such topics as the detection of environmental effects on spinach through comprehensive metabolic profiling.
  • Advances in developing screening methods and improving aluminum resistance in common bean and Brachiaria
    Idupulapati Rao, Peter Wenzl, Adriana Arango, John Miles, Toshihiro Watanabe, Takuro Shinano, Mitsuru Osaki, Tadao Wagatsuma, Germ?n Manrique, Stephen Beebe, Joe Tohme, Manabu Ishitani, Andr?s Rangel, Walter Horst
    Current Agricultural Science and Technology, 14, 4, 1, 7, 2008年
  • Metabolite profiling and assessment of metabolome compartmentation of soybean leaves using non-aqueous fractionation and GC-MS analysis
    Noureddine Benkeblia, Takuro Shinano, Mitsuru Osaki
    Metabolomics, 3, 3, 297, 305, 2007年09月, [査読有り]
    英語, 研究論文(学術雑誌), In the present study, non-aqueous fractionation (NAQF) and GC-MS were used to obtain a spatially resolved view of metabolism in mature leaves of soybean (Glycine max Merr.). NAQF of lyophilized soybean leaves was performed using CCl4-n-heptane and ultracentrifugation that yielded a gradient comprised of six fractions. Chlorophyll content, and marker enzyme activities, phosphoenolpyruvate carboxylase (PEPC) and α-mannosidase, were utilized as stroma, cytosol and vacuole markers, respectively. GC-MS analyses of each fraction resulted in the identification of around 100 different metabolites. The distribution of these identified compounds showed a decreasing order from the vacuole to cytosol to chloroplast stroma. In other words, a greater number of identified compounds were found in the vacuole when compared to the cytosol or stroma. Levels of sugars, organic acids and fatty acids showed greater relative abundances in the vacuole with 50, 55, and 50% of the respective pools. A greater relative abundance of amino acids was observed in the cytosol where 45% of the total of amino acids content was recorded. The relatively large pool of sugars and phenolic acids in the vacuole compartment implies high levels of starch metabolism and phenylpropanoid biosynthesis. The low amino acids pool, on the other hand, suggests low nitrogen accumulation in the leaves of soybean. Hierarchical cluster analysis on the most abundant metabolites revealed three clusters containing 10, 20, and 2 of the 32 selected metabolites. The data were discussed in term of NAQF and GC-MS analysis of soybean mature leaves, and also in term of distribution and compartmentation of metabolites at subcellular levels. © Springer Science+Business Media, LLC 2007.
  • Effects of elevated atmospheric CO2 concentration on the nutrient uptake characteristics of Japanese larch (Larix kaempferi)
    Takuro Shinano, Takuya Yamamoto, Keitaro Tawaraya, Masaru Tadokoro, Takayoshi Koike, Mitsuru Osaki
    TREE PHYSIOLOGY, 27, 1, 97, 104, HERON PUBLISHING, 2007年01月, [査読有り]
    英語, 研究論文(学術雑誌), We evaluated the response of Japanese larch (Larix kaempferi Sieb. & Zucc.) to elevated atmospheric CO2 concentration ([CO2]) (689 +/- 75 ppm in 2002 and 697 +/- 90 ppm in 2003) over 2 years in a field experiment with open-top charnbers. Root activity was assessed as nitrogen, phosphorus and potassium uptake rates estimated from Successive measurements of absorbed amounts. Dry matter production of whole plants was unaffected by elevated [CO2] in the first year of treatment, but increased significantly in response to elevated [CO2] in the second year. In contrast, elevated [CO2] increased the root to shoot ratio and fine root dry mass in the first year, but not in the second year. Elevated [CO2] had no effect on tissue N, P and K concentrations. Uptake rates of N, P and K correlated with whole-plant relative growth rates, but were unaffected by growth [CO2], as was ectomycorrhizal colonization, a factor assumed to be important for nutrient uptake in trees. We conclude that improved growth of Larix kaempferi in response to elevated [CO2] is accompanied by increased root biomass, but not by increased root activity.
  • GC-MS associated global analysis of root exudates of aceptically grown rice plant
    Katsumasa Suzuki, Shunji Tokutake, Mizue Anda, Keiki Okazaki, Masako Takebe, Takuro Shinano, Mitsuru Osaki
    PLANT AND CELL PHYSIOLOGY, 48, S68, S68, OXFORD UNIV PRESS, 2007年, [査読有り]
    英語
  • GC-MS metabolite profiling under different inorganic nitrogen sources of spinach (Spinacea orelacea L.).
    Keiki Okazaki, Norikuni Oka, Takuro Shinano, Mitsuru Osaki, Masako Takebe
    PLANT AND CELL PHYSIOLOGY, 48, S258, S258, OXFORD UNIV PRESS, 2007年, [査読有り]
    英語
  • Analysis of RNAi lines of novel gene OsPII, which is induced in rice plants grown under low p conditions
    Tonto Nishiyama, Sang Ja Choi, Takuro Shinano, Hiroyuki Koyama, Susumu Ito, Jun Wasaki, Mitsuru Osaki
    PLANT AND CELL PHYSIOLOGY, 48, S30, S30, OXFORD UNIV PRESS, 2007年, [査読有り]
    英語
  • The ability of p-acquisition by tobacco introduced secretory acid phosphatase gene of white lupin
    Hayato Maruyama, Miho Tanaka, Takuya Yamamura, Takuro Shinano, Susumu Ito, Jun Wasaki, Mitsufu Osaki
    PLANT AND CELL PHYSIOLOGY, 48, S30, S30, OXFORD UNIV PRESS, 2007年, [査読有り]
    英語
  • Plant growth promotion abilities and microscale bacterial dynamics in the rhizosphere of Lupin analysed by phytate utilization ability
    Y Unno, K Okubo, J Wasaki, T Shinano, M Osaki
    ENVIRONMENTAL MICROBIOLOGY, 7, 3, 396, 404, BLACKWELL PUBLISHING LTD, 2005年03月, [査読有り]
    英語, 研究論文(学術雑誌), In the rhizosphere, phosphorus (P) levels are low because of P uptake into the roots. Rhizobacteria live on carbon (C) exuded from roots, and may contribute to plant nutrition by liberating P from organic compounds such as phytates. We isolated over 300 phytate (Na-inositol hexa-phosphate; Na-IHP)-utilizing bacterial strains from the rhizosheath and the rhizoplane of Lupinus albus (L.). Almost all of the isolates were classified as Burkholderia based on 16S rDNA sequence analysis. Rhizosheath isolates cultured with Na-IHP as the only source of C and P showed lower P uptake at the same extracellular phytase activity than rhizoplane strains, suggesting that bacteria from the rhizosheath utilized phytate as a C source. Many isolates also utilized insoluble phytate (Al-IHP and/or Fe-IHP). In co-culture with Lotus japonicus seedlings, some isolates promoted plant growth significantly.
  • Production of maize in the karst mountain area of South-West China
    T. Shinano, Z. Taigen, T. Yamamura, Y. Meng, W. Lu, H. Tan
    TROPICAL AGRICULTURE, 81, 4, 204, 210, TROPICAL AGRICULTURE, 2004年10月, [査読有り]
    英語, 研究論文(学術雑誌), A village was selected in a basin within the karst mountain area in south-western China, with the aim of increasing the productivity of maize and highlighting the problem(s) of the farming system. The rock of the Karst Mountains surrounding the village is composed of dolomite, and thus, the soil contains a large amount of Ca and Mg and a relatively small amount of K. The cropping land was separated into flat and sloping areas and slopes up to 25 degrees were utilized for the production of maize, because of population pressure. In the sloping areas, the available P content was very poor compared with the flat area where a large amount of available P was observed from the top layer to a depth of 70 cm. Although the soil was poor in P and (or) K, farmers only applied manure and N in the form of ammonium carbonate [ (NH4)(2)CO3]. The amount of N applied by the farmers as manure was normally 100-200 kg N ha(-1) and (NH4)(2)CO3 was applied at the rate of 60.5 kg N ha(-1) twice during the growing season (150 days). This caused about 50-70% of the applied N to be left in the field. An increase in productivity and N use efficiency was achieved by using a chemical K fertilizer in the flat areas. It is proposed that there is a need to reduce the amount of manure and (NH4)(2)CO3 used in this area and that the proper application of K in flat areas and P and K in sloping areas could improve the productivity of maize and N use efficiency of applied manure.
  • Production of lupin acid phosphatase in transgenic rice for use as a phytate-hydrolyzing enzyme in animal feed
    A Hamada, K Yamaguchi, M Harada, S Nikumaru, J Wasaki, T Shinano, H Matsui, M Osaki, H Honda
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 68, 7, 1611, 1616, TAYLOR & FRANCIS LTD, 2004年07月, [査読有り]
    英語, 研究論文(学術雑誌), The acid phosphatase gene from lupin was expressed in transgenic rice plants under the control of the maize ubiquitin promoter or rice chlorophyll a/b binding protein (Cab) promoter. Transgenic rice leaves exhibited up to an 18-fold increase in phytate-hydrolyzing activity. Based on the phytate-hydrolyzing activity at pH 5.5, more than 85% this activity was retained after heat-treatment at 80degreesC for 15min, and the heterologous enzyme in leaf sections and leaf extracts was relatively stable during storage. A distinct increase in released phosphate was observed when the heterologous enzyme was mixed with the feed extract. These results suggest that the heterologous enzyme in rice plants may maintain its desired characteristics as a phytate-hydrolyzing enzyme when added to animal feed.
  • Starch properties of the sago palm (Metroxylon sagu Rottb.) in different soils
    K. Nozaki, T. Nuyim, T. Shinano, S. Hamada, H. Ito, H. Matsui, M. Osaki
    Plant Foods for Human Nutrition, 59, 3, 85, 92, 2004年07月, [査読有り]
    英語, 研究論文(学術雑誌), We investigated the relationships between starch concentrations and activities of starch synthetic enzymes in sago palms (Metroxylon sagu Rottb.) under acid sulfate and mineral soil conditions. Plants grown naturally that had reached their maturated stage were sampled. We found that the growth in acid sulfate soil is lower than that in mineral soil and that starch granules were larger and there was more amylase activity in acid sulfate soil than in mineral soil. Lower amylase activity in mineral soil could eliminate the degradation of starch, making the smaller granules suitable for storing large amounts of starch in a limited space inside cells.
  • Low phosphorus tolerance mechanisms: Phosphorus recycling and photosynthate partitioning in the tropical forage grass, Brachiaria hybrid cultivar mulato compared with rice
    M Nanamori, T Shinano, J Wasaki, T Yamamura, IM Rao, M Osaki
    PLANT AND CELL PHYSIOLOGY, 45, 4, 460, 469, OXFORD UNIV PRESS, 2004年, [査読有り]
    英語, 研究論文(学術雑誌), The Brachiaria hybrid cv. Mulato is well adapted to low-fertility acid soils deficient in phosphorus (P). To study the grassy forage's mechanisms for tolerating low P supply, we compared it with rice (Oryza sativa L. cv. Kitaake). We tested by using nutrient solution cultures, and quantified the effects of P deficiency on the enzymatic activities of phosphohydrolases and on carbon metabolism in P-deficient leaves. While P deficiency markedly induced activity of phosphohydrolases in both crops, the ratio of inorganic phosphorus to total P in leaves was greater in Brachiaria hybrid. Phosphorus deficiency in leaves also markedly influenced the partitioning of carbon in both crops. In the Brachiaria hybrid, compared with rice, the smaller proportion of (14)C partitioned into sugars and the larger proportion into amino acids and organic acids in leaves coincided with decreased levels of sucrose and starch. Hence, in P-deficient leaves of the Brachiaria hybrid, triose-P was metabolized into amino acids or organic acids. Results thus indicate that the Brachiaria hybrid, compared with rice, tolerates low P supply to leaves by enhancing sugar catabolism and by inducing the activity of several phosphohydrolases. This apparently causes rapid P turnover and enables the Brachiaria hybrid to use P more efficiently.
  • Micro-spatial distribution of bacteria in the rhizosphere
    Y Unno, T Shinano, J Wasaki, M Osaki
    BIOLOGICAL RESOURCES AND MIGRATION, 157, 160, SPRINGER-VERLAG BERLIN, 2004年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), Long-term experimental fields (having either no nitrogen, phosphorus, or potassium fertilizer or with complete application of N, P, and K fertilizers since 1914) were used for the investigation of bacterial habitat distribution in the rhizosphere. From the rhizosphere of Lupinus albus L., we screened rhizobacteria by their utilization ability of phytate as sole carbon (C) and phosphorus (P) source. Though almost all of the isolates were identified as Burkholderia genus, there was a wide variation in their phosphate utilization. By comparing isolates from rhizosphere soil and isolates from the rhizoplane, those isolates from the latter exhibit higher inorganic phosphate uptake ability when compared at the same extracellular phytase level. We propose that phytate-utilizing bacteria may adapt and segregate from their habitat along a spatial gradient of C and P availability in the rhizosphere. That is, rhizobacteria, which live very close to the rhizoplane, utilize phytate mainly as a P source rather than as a C source, because a large amount of C is provided from roots, whereas this may not be true for P. On the other hand, rhizosphere bacteria that live in a remote area from roots utilize phytate as a C source rather than as a P source, because the lack of available C may restrict the growth of bacteria.
  • Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands
    M Osaki, T Watanabe, T Ishizawa, C Nilnond, T Nuyim, T Shinano, M Urayama, SJ Tuah
    PLANT FOODS FOR HUMAN NUTRITION, 58, 2, 93, 115, KLUWER ACADEMIC PUBL, 2003年, [査読有り]
    英語, 研究論文(学術雑誌), Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed in the lowlands of Thailand and Malaysia. The nutrient concentrations in the leaves of plants grown in these type of soils were studied with the aim of developing a nutritional strategy for adapting to such problem soils. In sago and oil palms that were well-adapted to peat soil, the N, P, and K concentrations were the same in the mature leaves, while the Ca, Mg, Na, and Fe concentrations were higher in the mature leaves of the oil palm than of the sago palm. Melastoma malabathricum and Melaleuca cajuputi plants that were well-adapted to low pH soils, peat, and acid sulfate soils were also studied. It was observed that a high amount of Al accumulated in the M. marabathricum leaves, while Al did not accumulate in M. cajuputi leaves. M. cajuputi plants accumulated large amounts of Na in their leaves or stems regardless of the exchangeable Na concentration in the soil, while M. malabathricum that was growing in saline-affected soils excluded Na. Positive relationships between macronutrients were recognized between P and N, between K and N, and between P and K. Al showed antagonistic relationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showed antagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weak antagonistic relationships with Zn, Mn, Cu, and Al.
  • Analyses of rice genes respond on low phosphorus condition using microarrays
    J Wasaki, R Yonetani, S Kuroda, T Shinano, J Yazaki, F Fujii, K Shinbo, K Yamamoto, K Sakata, T Sasaki, N Kishimoto, S Kikuchi, M Osaki
    PLANT AND CELL PHYSIOLOGY, 43, S238, S238, OXFORD UNIV PRESS, 2002年, [査読有り]
    英語
  • Influence of carbon-nitrogen balance on productivity of C-3 plants and effect of high expression of phosphoenolpyruvate carboxylase in transgenic rice
    M Osaki, T Shinano
    REDESIGNING RICE PHOTOSYNTHESIS TO INCREASE YIELD, 7, 177, 192, ELSEVIER SCIENCE BV, 2000年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス), A root-shoot interaction model is proposed to explain the high productivity of high-yielding varieties of several crops, based on high-yielding trials. In the high-yielding varieties, nitrogen is always actively absorbed during the vigorous sink organ-filling stage (maturation or the ripening stage of growth), Thus, photosynthetic rate (dry matter increase) and root activity (nutrient absorption) remained constant during maturation in high-yielding varieties because a high photosynthetic rate maintains a high root activity by supplying a sufficient amount of photosynthate to the roots, a phenomenon referred to as root-shoot interaction for high productivity. On the other hand, in the varieties with standard yield, hereafter referred to as standard or old or low-yielding varieties, the photosynthetic rate decreased, followed by a decrease in root activity because of the reduced carbohydrate supply; nitrogen incorporated into leaves and stems before maturation was retranslocated during maturation.
    Two carbon-nitrogen (C-N) interaction models are developed. One is DMt = DM0 exp (CNI x N-t) for cereals and the other is DMt = DM0 + CNI ' x N-t for legumes, where DMt is the dry weight of a plant at a given time, N-t is the amount of N accumulated in the plant at a given time, DM, is the initial dry weight, and CNI and CNI ' are the C-N indices. Moreover, the productivity per unit amount of N accumulated in legumes is quite low compared with that in cereals during the vegetative growth stage. This is caused by the low growth efficiencies [accumulated dry matter/(accumulated dry matter + respiration)] of whole plants regardless of nitrogen concentration, indicating that the concept of growth and maintenance respiration is not valid.
    The fate of photosynthesized (CO2)-C-14 was quite different between rice and soybean. In soybean, a large amount of photosynthesized (CO2)-C-14 is respired in the light compared with that in the dark, but in rice the amount of C-14 retained in the leaves is similar regardless of light conditions. This high respiratory loss of current photosynthate in soybean in the light can be explained partly by the high rate of photorespiration in the leaves. A large portion of photosynthetically fixed (CO2)-C-14 in soybean in the light was distributed into organic acids, amino acids, and protein compared with that in rice, where metabolism of newly fixed carbon is mainly regulated by the activity of sucrose-phosphate synthase (SPS) and especially phosphoenolpyruvate carboxylase (PEPC). Thus, it is assumed that the carbon-nitrogen balance of the whole plant is regulated by (1) whether current photosynthate distributes into the tricarboxylic acid cycle or sucrose metabolism in the light, which is regulated by PEPC or SPS, respectively, and (2) whether photorespiratory activity is high or not. This information will help to improve crop productivity through regulation of carbon-nitrogen metabolism.
    The distribution of (CO2)-C-14 to chemical compounds was studied in transgenic rice plants that showed high expression of the maize PEPC gene. The C/N ratio decreased in transgenic plants compared with controls because of high C-14 distribution to organic acids. As the transgenic plant could exude much organic acid from the roots, this plant showed aluminum tolerance for high aluminum in solution.
  • Structure of a cDNA for an acid phosphatase from phosphate-deficient lupin (Lupinus albus L.) roots
    J Wasaki, M Omura, M Osaki, H Ito, H Matsui, T Shinano, T Tadano
    SOIL SCIENCE AND PLANT NUTRITION, 45, 2, 439, 449, TAYLOR & FRANCIS LTD, 1999年06月, [査読有り]
    英語, 研究論文(学術雑誌), We have isolated a cDNA clone, named LASAP1, for an acid phosphatase (EC 3.1.3.2; APase) from a cDNA library constructed from mRNA in phosphate-deficient lupin (Lupinus albus L. cv. Kievskij) roots. LASAP1 was 2,187 bp in length including a single open reading frame of 1,914 nucleotides that encodes 638 amino acid residues containing a putative signal sequence of 31 amino acids. The polypeptide encoded by LASAP1 was highly hydrophilic, while the putative signal peptide was highly hydrophobic. It was predicted that the peptide had a high affinity to the plasma membrane. The deduced amino acid sequence shared a high homology with that of purple APases from germinated seeds of Phaseolus vulgaris and those secreted from Arabidopsis thaliana. Seven amino acids composing the active center of the Phaseolus vulgaris purple APase were conserved in all the homologous APases. Northern blot analysis revealed that the corresponding mRNA accumulated in both shoots and roots under phosphate deficient conditions, and that the amount of transcript in the roots was much larger than that in the shoots. These results suggest that APase encoded by LASAP1 cDNA is expressed predominantly in the roots.
  • Difference in system of current photosynthesized carbon distribution to carbon and nitrogen compounds between rice and soybean
    T Nakamura, M Osaki, T Shinano, T Tadano
    SOIL SCIENCE AND PLANT NUTRITION, 43, 4, 777, 788, JAPANESE SOC SOIL SCIENCE PLANT NUTRITION, 1997年12月, [査読有り]
    英語, 研究論文(学術雑誌), (CO2)-C-14 was assimilated during 10 min in leaf of rice and soybean under 21 kPa O-2 (21% O-2 treatment) and 2 kPa O-2 (2% O-2 treatment) at the vegetative growth stage and flowering stage. The C-14 distribution ratio to respired CO2 and crude chemical components (sugars, polysaccharides, amino acids, organic acids, and proteins) was determined. In this paper, since emphasis was placed on the C-14 distribution mechanism to carbon compounds and nitrogen compounds, the terms carbon metabolism pool (C-pool) composed of sugars and polysaccharides, and nitrogen metabolism pool (N-pool) composed of organic acids, amino acids and proteins were used. The results obtained were as follows.
    C-14 distribution ratio to N-pool at 0 min after C-14 assimilation was higher in soybean than in rice regardless of the treatments and stages, and that at 30 min after C-14 assimilation under light condition markedly decreased both in rice and soybean. Therefore, especially in soybean, a large amount of photosynthesized C-14 was once distributed to the N-pool, then C-14 compounds in the N-pool were reconstructed into the C-pool. During this reconstruction process, C-14 compounds in the N-pool were actively respired.
    C-14 distribution to N-pool at 0 min after C-14 assimilation changed slightly or did not change by the N treatment. C-14 distribution to N-pool in the -N treatment of soybean (13-29 mg N g(-1) content in leaves) was higher than that in the +N treatment of rice (31-48 mg N g(-1) content in leaves). Photosynthesized carbon distribution to N-pool in rice decreased with growth, while it remained constant in soybean. Accordingly, in soybean, photosynthesized carbon was predominantly distributed to the N-pool through photorespiration and/or Calvin cycle (supplying triose-P), which was less affected by nitrogen nutrient and aging. Thus, the mechanism of photosynthesized carbon distribution to carbon and nitrogen compounds was basically regulated by inherited characters of each plant more than by the nitrogen status of leaves.
    By the 2% 0, treatment, C-14 distribution to N-pool decreased in both crops regardless of N treatment, indicating that photorespiration plays an important role in the supply of the preliminarily photosynthesized carbon compounds to N-pool. In the 2% O-2 treatment, C-14 distribution to N-pool was higher in soybean than in rice, indicating that triose-P transported from chloroplast was preferentially distributed to N-pool in the case of soybean.
  • PRODUCTIVITY OF HIGH-YIELDING CROPS .5. ROOT-GROWTH AND SPECIFIC ABSORPTION RATE OF NITROGEN
    M OSAKI, T SHINANO, M MATSUMOTO, J USHIKI, MM SHINANO, M URAYAMA, T TADANO
    SOIL SCIENCE AND PLANT NUTRITION, 41, 4, 635, 647, JAPANESE SOC SOIL SCIENCE PLANT NUTRITION, 1995年12月, [査読有り]
    英語, 研究論文(学術雑誌), ''Standard yield variety'' and ''high-yielding variety'' of rice, winter wheat, maize, soybean, potato, beet, and sunflower were grown, and the relationship between root growth and absorption of nitrogen was studied. To estimate the role of root in nitrogen absorption, nitrogen absorption rate (Delta N, g N m(-2) d(-1)) was parameterized into root dry weight (RW, g m(-2)) and specific absorption rate of nitrogen per root dry weight (SAR(N), Delta N RW(-1)).
    1) Since during the vegetative growth stage, the correlation between Delta N and crop growth rate (CGR) was high, Delta N was under the control of shoot demand for nitrogen, while during the early maturing stage, Delta N was well correlated with SAR(N) except for sunflower. Thus, Delta N at the vegetative growth stage was regulated by shoot growth (CGR), which was related to RW sometimes. Thereafter, Delta N was regulated by SAR(N) with the progression of growth
    2) Based on the cluster analysis of SAR(N) or RW for Delta N, and correlation between Delta N and SAR(N) or RW, crops were classified into three groups: group (I), soybean, potato, and beet; group (II), rice, winter wheat, and maize; and group (III), sunflower. During the early maturating stage, Delta N of group (I) was regulated by mainly SAR(N), Delta N of group (II) was regulated by both SAR(N) and RW, and Delta N of group (III) was regulated mainly by RW.
    3) SAR(N) remained high during the early maturation stage in the ''high-yielding variety'' of crops.
  • N-15-ALLOCATION OF (NH4)-N-15-N AND (NO3)-N-15-N TO NITROGENOUS COMPOUNDS AT THE VEGETATIVE GROWTH STAGE OF POTATO PLANTS
    M OSAKI, J SHIRAI, T SHINANO, T TADANO
    SOIL SCIENCE AND PLANT NUTRITION, 41, 4, 699, 708, JAPANESE SOC SOIL SCIENCE PLANT NUTRITION, 1995年12月, [査読有り]
    英語, 研究論文(学術雑誌), Effect of NH4+ and NO3- on N-15-allocation to organs and nitrogenous compounds in potato plants (Solanum tuberosum L.) was examined in hydroponic culture using an automatic pH control system, and the results obtained were as follows.
    1) Growth of upper leaves was stimulated by NH4+ because (NH4)-N-15-N was preferentially distributed into upper leaves compared to (NO3)-N-15-N which was mainly distributed to lower leaves.
    2) At the vegetative growth stage, (NH4)-N-15-N and (NO3)-N-15-N distribution among organs was almost similar except for roots, whereas at the tuber swelling stage, (NH4)-N-15-N was distributed to stems and roots, and (NO3)-N-15-N was distributed to leaves.
    3) N-15 amino acid metabolism was affected by NH4+ or NO3-, for example, in leaves grown in (NH4)-N-15-N, the contents of aspartic acid and asparagine (Asx) increased with growth, while those of glutamic acid and glutamine (Glx) decreased with growth. In leaves grown in (NO3)-N-15-N, the Asx content remained constant, but the Glx content increased with growth. In tubers, (NH4)-N-15-N was distributed to Asx at first, but (NO3)-N-15-N was distributed to Glx. Thus, the metabolism and translocation pattern of Asx and Glx were quite different depending on the nitrogen forms.
  • EFFECTS OF AMMONIUM AND NITRATE ASSIMILATION ON THE GROWTH AND TUBER SWELLING OF POTATO PLANTS
    M OSAKI, J SHIRAI, T SHINANO, T TADANO
    SOIL SCIENCE AND PLANT NUTRITION, 41, 4, 709, 719, JAPANESE SOC SOIL SCIENCE PLANT NUTRITION, 1995年12月, [査読有り]
    英語, 研究論文(学術雑誌), Effect of NH4-N and NO3-N on plant growth and tuber smelling of potato plant (Solanum tuberosum L.) was examined, and the results obtained were as follows.
    1) NH4-N stimulated tuber swelling, while NO3-N stimulated the branching of stolons and stems, and shoot growth.
    2) In plants grown with NH4-N, a large amount of (NH4)-N-15-N was mainly partitioned into tubers and stems, whereas in plants grown with NO3-N, (NO3)-N-15-N was mainly partitioned into leaves, especially into the insoluble fraction.
    3) Aspartic acid plus asparagine (Asx) in tubers predominated among amino acids and amides when the plants were grown with NH4-N. Also (NH4)-N-15-N was incorporated into Asx in tubers, while, (NO3)-N-15-N was presumably transported to tubers in the form of Asx, which subsequently was actively metabolized into other amino acids in tubers.
    Thus, as the nitrogen form of NH4+ appeared to stimulate the Asx metabolism, Asx was transported to tubers, and mainly stored in tubers. On the other hand, the nitrogen form of NO3- was mainly transported into leaves, and NO3-N promoted vegetative growth.
  • COMPARISON OF PRODUCTION EFFICIENCY AMONG FIELD CROPS RELATED TO NITROGEN NUTRITION AND APPLICATION
    T SHINANO, M OSAKI, T TADANO
    PLANT NUTRITION - FROM GENETIC ENGINEERING TO FIELD PRACTICE, 45, 227, 230, KLUWER ACADEMIC PUBL, 1993年, [査読有り]
    英語, 研究論文(国際会議プロシーディングス)

その他活動・業績

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    Tsinghua University Press, Beijing, P.R. China., 2005年, 7302117861, “Cytokinins and gene expression in different senescence types of maize”In Li, C., Zhang, F.S., Dobermann, A., Hinsinger, P., Lambers, H., Li, X.L., Marschner, P., Maene, L., McGrath, S., Oenema, O., Peng, S.B., Rengel, Z., Shen, Q.R., Welch, R., von Wirén, N., Yan, X.L. and Zhu, Y.G. (eds.) Plant Nutrition. – for Food Security, Human Health and Environmental Protection.
  • “Whole aspect of phosphorus stress metabolisms applying transcriptomic and proteomic analysis of rice plant”.In Li, C., Zhang, F.S., Dobermann, A., Hinsinger, P., Lambers, H., Li, X.L., Marschner, P., Maene, L., McGrath, S., Oenema, O., Peng, S.B., Ren・・・               
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