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Mizuta Hiroyuki

Faculty of Fisheries Sciences　Marine Life Science　Aquaculture Genetics and GenomicsProfessor

Researcher basic information

■ Degree
  • 博士（水産学）, 北海道大学
■ URL
researchmap URL■ Various IDs
J-Global ID■ Research Keywords and Fields
Research Keyword
  • 生活環制御
  • 防御応答
  • 栄養塩
  • コンブ類
  • 成熟
  • 子嚢斑
  • 培養
  • 環境要因
  • 植物成長調整物質
  • 再分化
  • 植物生長調整物質
  • 抵抗性
  • 組織培養
  • 種苗
  • 光質
  • 活性酸素
  • マコンブ
  • ヨウ素
  • 増殖
  • 繁殖
  • 生態系モデル
  • 基礎生産
  • スサビノリ
Research Field
  • Life Science, Aquatic bioproduction science, 海藻増養殖
  • Life Science, Aquatic life science, 海藻繁殖生理学
■ Educational Organization

Career

■ Career
Career
  • 2013 - Present
    北海道大学 水産科学研究研究院, 教授

Research activity information

■ Papers
■ Other Activities and Achievements
■ Lectures, oral presentations, etc.
■ Syllabus
  • 育種生物学特論Ⅰ, 2024年, 修士課程, 水産科学院
  • 育種生物学特論Ⅱ, 2024年, 修士課程, 水産科学院
  • Introduction to Fisheries Sciences Ⅱ（水産科学汎論Ⅱ）, 2024年, 修士課程, 水産科学院
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 大学院共通授業科目（一般科目）：自然科学・応用科学, 2024年, 修士課程, 大学院共通科目
  • 環境と人間, 2024年, 学士課程, 全学教育
  • 水産増殖学, 2024年, 学士課程, 水産学部
  • 水産増養殖実習, 2024年, 学士課程, 水産学部
  • 水産科学英語Ⅰ, 2024年, 学士課程, 水産学部
  • 水産科学英語Ⅱ, 2024年, 学士課程, 水産学部
  • 海洋植物学, 2024年, 学士課程, 水産学部
  • 基礎生命科学実験, 2024年, 学士課程, 水産学部
  • 発生・組織学, 2024年, 学士課程, 水産学部
■ Affiliated academic society
  • THE JAPANESE SOCIETY OF APPLIED PHYCOLOGY
  • JAPANESE SOCIETY FOR AQUACULTURE SCIENCE
  • THE JAPANESE SOCIETY OF PHYCOLOGY
  • THE JAPANESE SOCIETY OF FISHERIES SCIENCE
■ Research Themes
  • コンブ微小世代のシードバンクとしての能力と実海域における生残性の把握
    科学研究費助成事業
    01 Apr. 2020 - 31 Mar. 2023
    水田 浩之
    コンブ胞子体（巨視的世代）は、ストレスを受けると活性酸素を生産し様々な防御機構を誘導することが知られている。その一つとして、胞子体にはオキシダティブバーストによって誘導されるケイ素の細胞外取り込み機構が存在し、この機構が微小世代である配偶体にも備わっていることが示唆された。ケイ素の細胞外取り込み機構は、過酸化水素とハロペルオキシダーゼの存在下でポリフェノールとケイ素が架橋形成することで細胞壁の強化を図っているものと考えられ、配偶体のストレス防御機構の一端が明らかになった。
    また、配偶体が他の藻類の下草等として生存・越年する状況を想定し、配偶体を5℃、遮光下で、培地の交換をせずに1～16カ月保存培養し、生残率を測定した。その後保存配偶体を10℃、白色光下（5-10 μmol photons m-2 s-1, 12hr明暗周期）で培養し、成長・成熟過程を観察した。さらに配偶体のクロロフィル蛍光パラメーター（Fv/Fm、Y(Ⅱ)、rETR、NPQ）を、パルス変調クロロフィル蛍光測定装置を用いて測定した。その結果、1‐3カ月間保存した配偶体は保存前と同様の細胞観を呈し、80%以上の生残率と一定のFv/FmとNPQ値を維持し、正常に成長・成熟する能力を有することが明らかになった。6カ月および9カ月間保存した配偶体の平均生残率はそれぞれ68.4%、40.0％に低下し、9カ月の保存配偶体のFv/Fmは保存前の約70%の値に、NPQは約50%の値に低下した。Fv/FmとNPQはマコンブ配偶体の生残率と有意な相関性が認められたことから、長期保存したマコンブ種苗等の生残性を評価する上でFv/FmとNPQが有効な指標となることが明らかになった。
    日本学術振興会, 基盤研究(C), 北海道大学, 20K06176
  • A research on wounding-resistance inducing conditions in kelp sporophytes
    Grants-in-Aid for Scientific Research
    2013 - 2015
    Mizuta Hiroyuki
    We tried to search the effective conditions to induce the wounding-resistance in the kelp, particularly Saccharina japonica sporophyte. As a result, it has been found that the irradiation of monochromatic red light induces the hardening in the young sporophytes. In addition, the monochromatic red light irradiation resulted in the increase of lignin-like substance content. The lignin-like compounds and high peroxidase activity were histochemically detected in the cell wall and the adjacent apoplast, particularly of the epidermal cells. Moreover, the monochromatic red light irradiation induced the production of radical oxygen species, which play an important role for the defense mechanism. These observations suggest that red light irradiation functions for the young sporophytes to give the wounding-resistance by hardening of the epidermal cell wall with the deposition of lignin-like substances catalyzed by hydrogen peroxide and peroxidase.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, Competitive research funding, 25450268
  • A Study on constitutive resistance in the reproduction of kelp
    Grants-in-Aid for Scientific Research
    2010 - 2012
    MIZUTA Hiroyuki
    We focused on the role of constitutive resistance in the reproduction of kelp, particularly Saccharina japonica. It has been suggested that sori (reproductive organ in the sporophyte) have a high phenolic compound content and that they are protected by the release of iodine and radical oxygen species to combat biotic stresses. Silicon deposition is also considered to provide constitutive resistance in kelp sori. These phenomena suggest that wound-healing and kelp reproduction are supported by both constitutive and induced resistance mechanisms, and that silicon and phenolics deposition might contribute as protectants to the success of kelp reproduction.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, Competitive research funding, 22580195
  • ノリの無性生殖強化による簡便・高効率生産技術の開発
    産学が連携した研究開発成果の展開 研究成果展開事業 地域事業 地域イノベーション創出総合支援事業 シーズ発掘試験
    2009 - 2009
    水田 浩之
    ノリ養殖過程は、次年度の栽培のため糸状体(ノリの微小世代)を培養し、採苗を経て漁場へ展開するため、時間やコストもかかる。また、その過程では病気等の問題も発生しており、短時間での種苗補充が必要となる場合がある。そこで、多くの有用物質を含み社会的需要の高いノリについて、再生可能な遊離細胞の獲得機構の解明を進めると共に、連続的な種苗採取を念頭に置いた高効率かつ高効率の生産技術の開発を目指す。
    北海道大学, Principal investigator
  • Research on improvement of efficient callus production technique in Laminaria plants
    Grants-in-Aid for Scientific Research(基盤研究(C))
    2004 - 2006
    Hiroyuki MIZUTA
    Callus induction and rapid callus propagation in Laminariales plants, which are industrially and ecologically important seaweeds, cannot yet be applied for practical use to select and propagation of desired strain. There is a lack of knowledge regarding the physiological mechanism of callus induction and its growth. In this study, we examined the optimal conditions of callus induction and growth of Laminaria japonica sporophyte and discussed the physiological status of callus. The obtained results are summarized as described below.1.The optimal water temperature and salinity were 10℃ and more than 27.5 psu, respectively, which was similar to that of a whole plant.2.Nutrient-poor conditions decreased the induction rate of callus, and then the growth was stopped. In addition, vitamins were not effective to promote the callus induction.3.Three chelating substances including EDTA, EGTA, and NTA, slightly promoted callus induction or did not affect the induction. However, enrichment of nutrients with chelating substances resulted into the decrease the induction rate of callus.4.The callus induction occurred even in the dark, but the growth gradually decreased. The callus induction rate was significantly higher under red light compared with those under white and blue lights. Inversely, sorus formation was promoted by the irradiation of blue light, and was inhibited under red light.5.The addition of auxin and cytokinins to the culture medium promoted callus formation. It is suggested from microscopic observations that auxin plays an important role for cell division and the elongation, and cytokinins is effective to inhibit the discoloration. In addition, the difference of callus induction rate among parts along the sporophyte seemed to be due to the content of these plant growth regulators.
    Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 16580139
  • Gene expression analysis related to regulation of life cycle using Porphyra genomic information
    Grants-in-Aid for Scientific Research
    2003 - 2005
    SAGA Naotsune; YASUI Hajime; MIZUTA Hiroyuki; KITADE Yukihiro
    New findings obtained by this study are as follows.
    1. Screening of highly expressed genes during asexual sporulation through monospores
    We found eight genes encoding enzymes related to metabolism and unknown genes with gametophytic generation-phase-specific expression pattern by cDNA macroarray and RT-PCR or Northern analysis. The eight nucleotide sequences will appear in the GenBank/EMBL/DDBJ databases with accession numbers AB127044 through AB127051.
    2. Development of a new technique for gene expression analysis and internal standard in Porphyra yezoensis
    (1) We developed a method for whole-mount in situ hybridization (WISH) by using elongation factor-1α (EF-1α) riboprobes and gametophytic germlings.
    (2) We developed an internal standard (actin-related protein 4 homologue) in gene expression analyses of differentially expressed genes. A putative bipartite nuclear localization signal (NLS) and an actin motif were found within the PyARP4 amino acid sequences. The expression level of PyARP4 did not change significantly among four developmental stages of the life cycle and was lower than that of a conventional actin.
    3. Induction of monospore production by chemical treatment
    We found that monospore-like cells with germinability can be obtained when vegetative gametophytic thalli of P.yezoensis were grown in enriched seawater medium that contained 10 mM allantoin. We also found that this chemical treatment is effective to even gametophytic thalli of P.pseudolinearis, which does not have asexual sporulation through monospores in the life cycle.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 15380126
  • Quantification of bio-elements dynamics in low - trophic level process of tidal flat region and the ecosystem model's construction
    Grants-in-Aid for Scientific Research
    2003 - 2005
    MONTANI Shigeru; KUDO Isao; MIZUTA Hiroyuki; TADA Kuninao; YANAGI Tetsuo; TSUTSUMI Hiroaki
    It is the basic producing process in the tidal flat region where an inclusive finding had been extremely limited up to now though it is assumed most that the animal for each unit area production is a high place on the earth in this research according to various bottlenecks in the research. It was executed to assume a detailed, long-term surveillance study to be a base about Dynamics of the food web following it, to advance the quantification of various sources about Ca, and to execute construction of the ecosystem model in a necessity and an indispensable tidal flat region to the environmental protection in the future at the same time planning. It is impossible to construct a general modeling of the tidal flat group scattered in an environmental place where which it is long and slender and the temperature environment etc. are greatly different only with the observation example in the tidal flat in one place in the south north like our country. Then, our research team selected a typical tidal flat in three places from Hokkaido to Kyushu, obtained this quality and the same kind of observation and the experiment result in each place, aimed at the added role in the living thing of parents element movement of the benthos with a scarce finding so far, and it aimed to construct an inclusive ecosystem model who included it from the primary manufacturing to higher-order production that became the first case in quantification and our country. Basic production of the bottom life diatom was able to be estimated accurately by the research executed in the mouth of a river tidal flat in Takamatsu. Moreover, it was clarified that the level was a value that exceeded basic production in seawater the Inland Sea. In addition, the relation between a benthic animal and an environmental factor was understood in detail. As a result, the amount of the living thing and the composition influenced the living thing by an environmental factor, and it was clarified that the living thing oneself was regenerating the environment oppositely. Finally, it succeeded in making an inclusive ecosystem model in the tidal flat region.
    Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 15201001
  • 培養系におけるマコンブ胞子体の成熟誘導に関する研究
    科学研究費補助金(奨励研究(A))
    1997 - 1998
    水田 浩之
    マコンブLaminaria japonica胞子体片を用いて培養条件下で成熟誘導を試みた。また、自然環境下での子嚢斑形成状況と比較検討した結果、以下のことが明らかになった。1. 胞子体片を用いてた培養で子嚢斑形成が可能となった。2. 子嚢斑形成は15℃で最も早く、かつ大きな子嚢斑を形成した。3. 子嚢斑面積は高光量ほど大きかったが、その形成時期は光量に左右されにくかった。4. 短日条件下での子嚢斑形成は、等日および長日条件下に比べ早かった。5. 貧栄養条件は胞子体片の子嚢斑形成を遅らせかつ、その面積を著しく制限した。6. 子嚢斑形成には、ある一定以上の栄養元素の蓄積が必要であることが示唆された。7. 胞子体基部に比べ先端部の胞子体片の方が子嚢斑形成が早く、また中帯部に比べ縁辺部の方が容易に子嚢斑を形成する傾向が見られた。8. 自然環境下での子嚢斑形成は縁辺部に先立ち中帯部から形成される場合が多かった。9. 視覚的な子嚢斑形成以前に既に胞子体片内では種々の変化生じており、その変化は光合成の低下、呼吸の増加、タンパク質合成に特徴づけられる。10. ホソメコンブ、ガゴメ、アナメ胞子体片でも子嚢斑を形成させることができた。以上の結果から、一年中を通して個体やその採取部位によらず胞子体片を培養することにより子嚢斑を形成させることが可能であることが示された。この胞子体片を用いたマコンブは他のコンブ属植物にも応用でき、採苗方法は時期に左右されずに付着生物等の影響の少ない種苗を提供し得る可能性を示すものである。
    文部科学省, 奨励研究(A), 北海道大学, Principal investigator, Competitive research funding, 09760168
■ Industrial Property Rights
  • 褐藻類の種苗生産方法
    Patent right, 宮下 和夫; 水田 浩之; 宇治 利樹; 嵯峨 直恆; 川越 力, 国立大学法人北海道大学, 共和コンクリート工業株式会社
    特願2015-187808, 25 Sep. 2015
    特開2017-060429, 30 Mar. 2017
    201703005813581957
  • 海藻種苗の培養方法
    Patent right, 川越 力; 白石 恭輔; 北山 進一; 坂下 功; 吉野 博之; 菅原 智明; 玉森 学; 山田 芳浩; 安井 肇; 水田 浩之, 共和コンクリート工業株式会社, 公益財団法人函館地域産業振興財団, 株式会社東和電機製作所, 国立大学法人北海道大学
    特願2012-225210, 10 Oct. 2012
    特開2014-075998, 01 May 2014
    特許第5931684号
    201603000528375953
  • 海藻種苗の培養方法
    Patent right, 川越 力; 白石 恭輔; 北山 進一; 坂下 功; 吉野 博之; 菅原 智明; 玉森 学; 山田 芳浩; 安井 肇; 水田 浩之, 共和コンクリート工業株式会社, 公益財団法人函館地域産業振興財団, 株式会社東和電機製作所, 国立大学法人北海道大学
    特願2012-225210, 10 Oct. 2012
    特開2014-075998, 01 May 2014
    201403002145486180