Researcher basic information

• 博士(農学), 北海道大学

• https://researchmap.jp/0714?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201601005967801971
• http://www.agr.hokudai.ac.jp/ikushu/gelab/index.html

• 201601005967801971

• 遺伝資源
• 雑種強勢
• 環境制御
• オルガネラ
• ゲノム

• Environmental Science/Agriculture Science, Agricultural environmental engineering and agricultural information engineering
• Environmental Science/Agriculture Science, Science in plant genetics and breeding

• Bachelor's degree program, School of Agriculture
• Master's degree program, Graduate School of Agriculture
• Doctoral (PhD) degree program, Graduate School of Agriculture

Research activity information

• A key gene for vernalization-independent bolting under extra-long days in biennial sugar beet.
  Yosuke Kuroda; Kazuyoshi Kitazaki; Hiroaki Matsuhira; Tomohiko Kubo
  TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 139, 4, 27 Mar. 2026, [International Magazine]
  English, Scientific journal, A BvFT2 cis-haplotype is strongly associated with vernalization-independent bolting under extra-long days, providing a novel genetic resource for speed breeding and yield improvement in sugar beet. Sugar beet (Beta vulgaris) is a biennial crop that requires prolonged cold (vernalization) to induce bolting; this limits breeding speed. Recently, bolting by longer than natural daylength (BLOND) lines was reported to bolt and flower without vernalization under extra-long-day conditions. To identify the genetic basis of this trait, we conducted phenotypic, QTL, QTL-seq, and RNA-seq analyses using F₂ and F2:3 populations derived from crosses between BLOND and biennial lines. Bolting rates exhibited continuous distribution consistent with monogenic dominant inheritance. QTL and QTL-seq analyses identified a major locus at the terminal region of chromosome 4 (60.1-63.0 Mbp) containing BvFT2, an ortholog of FLOWERING LOCUS T (FT). RNA-seq revealed that BvFT2 expression was significantly higher in BLOND lines than in biennial lines under long-day conditions (FDR < 0.01), whereas BvBTC1 and BvFT1 showed no significant differences. Targeted Sanger sequencing of the BvFT2 locus detected several sequence variations, including insertions and SNPs in the 5' UTR and intron, as well as one nonsynonymous substitution in the coding region. Collectively, variation in BvFT2 defines a cis-haplotype strongly associated with BLOND-type bolting, providing a genetic target for speed breeding and yield-preserving strategies in sugar beet. We further validated that lines carrying the BvFT2 variant associated with high expression bolted under extended photoperiods in 29 additional breeding lines, including lines related to the mapping population, generally recapitulating the high bolting rates observed in the mapping population.
• Globular garden beet represents a distinct lineage in the domestication of Beta vulgaris.
  Ryo Hayakawa; Eigo Taniguchi; Mion Oishi; Sayuri Nishimura; Hiroaki Matsuhira; Tsubasa Narihiro; Yosuke Kuroda; Tomohiko Kubo; Kazuyoshi Kitazaki
  BMC plant biology, 26, 1, 216, 216, 05 Jan. 2026, [International Magazine]
  English, Scientific journal, BACKGROUND: A single plant species can give rise to multiple crop types, but the mechanisms underlying this diversification remain unclear. Clarifying the evolutionary relationships among these crops is a crucial first step in addressing this question. Cultivated beet (Beta vulgaris ssp. vulgaris) provides a good example, as it includes several distinct crop types, both vegetable and industrial, which are classified into cultivar groups. Among these are the swollen-rooted types, including the garden beet group and the sugar beet group. While the garden beet has traditionally been considered the ancestor of sugar beet, molecular genomic data indicated that the two are actually distantly related within this subspecies. We hypothesized that the genetic diversity of garden beet has been insufficiently characterized to clarify its evolutionary role within cultivated beets. One of our expectations was the discovery of an unrecognized lineage within garden beet genetic resources. RESULTS: We measured 15 taproot traits in 622 plants from 74 garden beet and 7 sugar beet accessions. Hierarchical clustering and principal component analysis of these phenotypic data revealed that the garden beet accessions can be divided into two groups. Visual inspection of the taproot images revealed that the accessions with conical taproots were grouped together with sugar beet, while accessions with globular (as well as other shapes such as cylindrical) taproots formed a separate group. Genomic DNA polymorphism analysis supported this grouping, a noticeable correlation with root morphology. Reanalysis of previous studies revealed that the globular group exhibits reduced mitochondrial polymorphism compared to the conical group. Moreover, garden beet accessions with genomic patterns showing unique demographic separation also displayed globular taproots, pointing to a possible genetic bottleneck during the evolution of this group. CONCLUSIONS: These findings indicate that the garden beet group with globular taproots is likely a distinct lineage in the evolution of cultivated beet. We favor the hypothesis that different cultivar groups, such as the (globular) garden beet group and the sugar beet group, originated from a genetically heterogenous population that served as the common ancestor of root-type beet. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12870-025-08056-7.
• Differences in restorer-of-fertility 1 haplotype polymorphism are associated with crop history of garden beet and sugar beet (Beta vulgaris L.)
  Eigo Taniguchi; Yohei Kanomata; Haruto Tanaka; Mion Oishi; Ryo Hayakawa; Hiroaki Matsuhira; Tsubasa Narihiro; Yosuke Kuroda; Hiroyo Kagami-Katsuyama; Tomohiko Kubo; Kazuyoshi Kitazaki
  Genetic Resources and Crop Evolution, Springer Science and Business Media LLC, 08 Feb. 2025
  Scientific journal
• Mitochondrial polymorphism of sea beet (Beta vulgaris ssp. maritima), a species with cytoplasmic male sterility.
  Tomoki Murata; Hiroyo Kagami-Katsuyama; Mion Oishi; Haruto Tanaka; Chihiro Sano; Jun Kashikura; Ryo Hayakawa; Keishi Kubota; Eigo Taniguchi; Keita Suzuki; Kazuyoshi Kitazaki; Tomohiko Kubo
  PloS one, 20, 9, e0332940, 2025, [International Magazine]
  English, Scientific journal, Cytoplasmic male sterility (CMS), a form of mitochondrion-induced male sterility, is a valuable trait for hybrid breeding in crop production. However, CMS is not universally present across all crop species, prompting ongoing efforts to identify CMS sources within genetic resources. The discovery of CMS could be facilitated by the development of predictive indices indicating the presence of CMS-associated mitochondria. One theory has proposed that populations containing CMS-expressing plants exhibit elevated mitochondrial polymorphism. Sea beet, a species known to harbor CMS, provides a suitable system for testing this prediction. We first conducted network analysis by using mitochondrial single nucleotide polymorphism sites extracted from publicly available nucleotide sequence data. The resulting network, constructed from 270 sea beet sequences, was complex yet characterized by several star-like clusters. Haplotypes from Mediterranean region were dispersed across the network, while those from Atlantic coast tended to cluster, supporting the hypothesis that sea beet originated in the Mediterranean area and later migrated to the Atlantic coast. We then analyzed four mitochondrial minisatellites-variable number of tandem repeat loci- across 973 plants of 172 sea beet accessions. Combination of alleles at these four loci defined 29 distinct mitotypes. Analysis of mitotype distribution revealed similarly high mitochondrial polymorphism (~0.87) in both the Mediterranean and the Atlantic regions, despite their genic differentiation. Most subregions within these areas contained 8-15 mitotypes; however, Denmark was a notable exception, with only a single mitotype detected among 139 plants from 11 accessions. This mitochondrial monomorphism contrasts with the diversity observed in neighboring Atlantic subregions, indicating that Danish sea beet constitutes an exceptional population. Notably, the Danish mitotype was not associated with any CMS, suggesting that the population may be devoid of CMS mitochondria- a condition in which the proposed mechanism for increased mitochondrial polymorphism would not be operative.
• Mitochondrial phylogeny and distribution of cytoplasmic male sterility-associated genes in Beta vulgaris
  Keishi Kubota; Mion Oishi; Eigo Taniguchi; Akiho Akazawa; Katsunori Matsui; Kazuyoshi Kitazaki; Atsushi Toyoda; Hidehiro Toh; Hiroaki Matsuhira; Yosuke Kuroda; Tomohiko Kubo
  PLOS ONE, 19, 9, e0308551, e0308551, Public Library of Science (PLoS), 27 Sep. 2024
  Scientific journal, Cytoplasmic male sterility (CMS) is a mitochondrial-encoded trait that confers reproductive defects in males but not in females or any vegetative function. Why CMS is so often found in plants should be investigated from the viewpoint of mitochondrial phylogeny. Beta vulgaris, including the wild subspecies maritima and cultivated subspecies vulgaris (e.g., sugar beet), is known to be mitochondrially polymorphic, from which multiple CMS mitochondria have been found, but their evolutionary relationship has been obscure. We first refined the B. vulgaris reference mitochondrial genome to conduct a more accurate phylogenetic study. We identified mitochondrial single-nucleotide polymorphic sites from 600 B. vulgaris accessions. Principal component analysis, hierarchical clustering analysis, and creation of a phylogenetic tree consistently suggested that B. vulgaris mitochondria can be classified into several groups whose geographical distribution tends to be biased toward either the Atlantic or Mediterranean coasts. We examined the distribution of CMS-associated mitochondrial genes from Owen, E- and G-type CMS mitochondria. About one-third of cultivated beets had Owen-type CMS, which reflects the prevalence of using Owen-type CMS in hybrid breeding. Occurrence frequencies for each of the three CMS genes in wild beet were less than 4%. CMS genes were tightly associated with specific mitochondrial groups that are phylogenetically distinct, suggesting their independent origin. However, homologous sequences of the Owen type CMS gene occurred in several different mitochondrial groups, for which an intricate explanation is necessary. Whereas the origin of cultivated beet had been presumed to be Greece, we found an absence of Owen-type mitochondria in Greek accessions.
• The cadmium-hypertolerant fern,Athyrium yokoscense, exhibits two cadmium stress mitigation strategies in the roots and the aerial parts
  Yuko Ukai; Hiroki Taoka; Manaka Kamada; Yuko Wakui; Fumiyuki Goto; Kazuyoshi Kitazaki; Tomoko Abe; Akiko Hokura; Toshihiro Yoshihara; Hiroaki Shimada
  Cold Spring Harbor Laboratory, 06 Dec. 2023
  Abstract
  
  Athyrium yokoscenseis hypertolerant to cadmium (Cd) and can grow normally under a high Cd concentration despite Cd being a highly toxic heavy metal. To mitigate Cd stress in general plant species, Cd is promptly chelated with a thiol compound and is isolated into vacuoles. Generated active oxygen species (ROS) in the cytoplasm are removed by reduced glutathione. However, we found many differences in the countermeasures inA. yokoscense. Thiol compounds accumulated in the stele of the roots, although a long-term Cd exposure induced Cd accumulation in the aerial parts. Synchrotron radiation-based X-ray fluorescence (SR-XRF) analysis indicated that a large amount of Cd was localized in the cell walls of the roots. Overexpression ofAyNramp5a, encoding a representative Fe and Mn transporter ofA. yokoscense, increased both Cd uptake and iron and manganese uptake in rice calli under the Cd exposure conditions. Organic acids were abundantly detected inA. yokoscenseroots. Investigating the chemical forms of the Cd molecules by X-ray absorption fine structure (XAFS) analysis detected many compounds with Cd-oxygen (Cd-O) binding inA. yokoscenseroots, whereas in the aerial parts, the ratio of the compounds with Cd-sulfur (Cd-S) binding was increased. Together, our results imply that the strong Cd tolerance ofA. yokoscenseis an attribute of the following two mechanisms: Cd-O compound formation in the cell wall is a barrier to reduce Cd uptake into aerial parts. Thiol compounds in the region of root stele are involved in detoxication of Cd by formation of Cd-S compounds.
  
  Statements and Declarations
  
  No potential conflict of interest was reported by the authors.
• Two cytoplasmic male sterility phenotypes in beet (Beta vulgaris L.): implications of their simultaneous onset and divergent paths
  Naoyuki Katsura; Kanna Itoh; Hiroaki Matsuhira; Yosuke Kuroda; Tomohiko Kubo; Kazuyoshi Kitazaki
  Euphytica, Springer Nature, Oct. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Nuclear DNA segments homologous to mitochondrial DNA are obstacles for detecting heteroplasmy in sugar beet (Beta vulgaris L.)
  Taniguchi E; Satoh K; Ohkubo M; Ue S; Matsuhira H; Kuroda Y; Kubo T; Kitazaki K
  PLOS ONE, Aug. 2023, [Peer-reviewed], [Corresponding author]
  English, Scientific journal
• Molecular genetics of cytoplasmic male sterility and restorer-of-fertility for the fine tuning of pollen production in crops.
  Kazuyoshi Kitazaki; Kotoko Oda; Akiho Akazawa; Ryoma Iwahori
  TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 136, 7, 156, 156, 18 Jun. 2023, [Peer-reviewed], [Invited], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal, Cytoplasmic male sterility (CMS) is an increasingly important issue within the context of hybrid seed production. Its genetic framework is simple: S-cytoplasm for male sterility induction and dominant allele of the restorer-of-fertility gene (Rf) for suppression of S. However, breeders sometimes encounter a phenotype of CMS plants too complex to be explained via this simple model. The molecular basis of CMS provides clue to the mechanisms that underlie the expression of CMS. Mitochondria have been associated with S, and several unique ORFs to S-mitochondria are thought to be responsible for the induction of male sterility in various crops. Their functions are still the subject of debate, but they have been hypothesized to emit elements that trigger sterility. Rf suppresses the action of S by various mechanisms. Some Rfs, including those that encode the pentatricopeptide repeat (PPR) protein and other proteins, are now considered members of unique gene families that are specific to certain lineages. Additionally, they are thought to be complex loci in which several genes in a haplotype simultaneously counteract an S-cytoplasm and differences in the suite of genes in a haplotype can lead to multiple allelism including strong and weak Rf at phenotypic level. The stability of CMS is influenced by factors such as the environment, cytoplasm, and genetic background; the interaction of these factors is also important. In contrast, unstable CMS becomes inducible CMS if its expression can be controlled. CMS becomes environmentally sensitive in a genotype-dependent manner, suggesting the feasibility of controlling the expression of CMS.
• Selection of nuclear genotypes associated with the thermo-sensitivity of Owen-type cytoplasmic male sterility in sugar beet (Beta vulgaris L.).
  Hiroaki Matsuhira; Kazuyoshi Kitazaki; Katsunori Matsui; Keisi Kubota; Yosuke Kuroda; Tomohiko Kubo
  TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 135, 5, 1457, 1466, 11 Feb. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, KEY MESSAGE: Cytoplasmic male sterility in sugar beet becomes thermo-sensitive when combined with specific genotypes, potentially offering a means to environmentally control pollination by this trait. The stability of cytoplasmic male sterility expression in several genetic backgrounds was investigated in sugar beet (Beta vulgaris L.). Nine genetically heterogenous plants from open-pollinated varieties were crossed with a cytoplasmic male sterile line to obtain 266 F1 plants. Based on marker analysis using a multiallelic DNA marker linked to restorer-of-fertility 1 (Rf1), we divided the F1 plants into 15 genotypes. We evaluated the phenotypes of the F1 plants under two environmental conditions: greenhouse rooms with or without daytime heating during the flowering season. Three phenotypic groups appeared: those consistently expressing male sterility, those consistently having restored pollen fertility, and those expressing male sterility in a thermo-sensitive manner. All plants in the consistently male sterile group inherited a specific Rf1 marker type named p4. We tested the potential for thermo-sensitive male sterile plants to serve as seed parents for hybrid seed production, and three genotypes were selected. Open pollination by a pollen parental line with a dominant trait of red-pigmented hypocotyls and leaf veins resulted in seed setting on thermo-sensitive male sterile plants, indicating that their female organs were functional. More than 99.9% of the progeny expressed the red pigmentation trait; hence, highly pure hybrids were obtained. We determined the nucleotide sequences of Rf1 from the three genotypes: One had a novel allele and two had known alleles, of which one was reported to have been selected previously as a non-restoring allele at a single U.S. breeding station but not at other stations in the U.S., or in Europe or Japan, suggesting environmental sensitivity.
• Nuclear and mitochondrial DNA polymorphisms suggest introgression contributed to garden beet (Beta vulgaris L.) domestication
  Yohei Kanomata; Ryo Hayakawa; Jun Kashikura; Kosuke Satoh; Hiroaki Matsuhira; Yosuke Kuroda; Kazuyoshi Kitazaki; Tomohiko Kubo
  GENETIC RESOURCES AND CROP EVOLUTION, Jun. 2021, [Peer-reviewed]
  English, Scientific journal
• A Lineage-Specific Paralog of Oma1 Evolved into a Gene Family from Which a Suppressor of Male Sterility-Inducing Mitochondria Emerged in Plants.
  Takumi Arakawa; Hiroyo Kagami; Takaya Katsuyama; Kazuyoshi Kitazaki; Tomohiko Kubo
  Genome biology and evolution, 12, 12, 2314, 2327, Oxford University Press (OUP), 06 Dec. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Cytoplasmic male sterility (MS) in plants is caused by MS-inducing mitochondria, which have emerged frequently during plant evolution. Nuclear restorer-of-fertility (Rf)genes can suppress their cognate MS-inducing mitochondria. Whereas many Rfs encode a class of RNA-binding protein, the sugar beet (Caryophyllales) Rf encodes a protein resembling Oma1, which is involved in the quality control of mitochondria. In this study, we investigated the molecular evolution of Oma1 homologs in plants. We analyzed 37 plant genomes and concluded that a single copy is the ancestral state in Caryophyllales. Among the sugar beet Oma1 homologs, the orthologous copy is located in a syntenic region that is preserved in Arabidopsis thaliana. The sugar beet Rf is a complex locus consisting of a small Oma1 homolog family (RF-Oma1 family) unique to sugar beet. The gene arrangement in the vicinity of the locus is seen in some but not all Caryophyllalean plants and is absent from Ar. thaliana. This suggests a segmental duplication rather than a whole-genome duplication as the mechanism of RF-Oma1 evolution. Of thirty-seven positively selected codons in RF-Oma1, twenty-six of these sites are located in predicted transmembrane helices. Phylogenetic network analysis indicated that homologous recombination among the RF-Oma1 members played an important role to generate protein activity related to suppression. Together, our data illustrate how an evolutionarily young Rf has emerged from a lineage-specific paralog. Interestingly, several evolutionary features are shared with the RNA-binding protein type Rfs. Hence, the evolution of the sugar beet Rf is representative of Rf evolution in general.
• The molecular basis for allelic differences suggests Restorer-of-fertility 1 is a complex locus in sugar beet (Beta vulgaris L.).
  Takumi Arakawa; Muneyuki Matsunaga; Katsunori Matsui; Kanna Itoh; Yosuke Kuroda; Hiroaki Matsuhira; Kazuyoshi Kitazaki; Tomohiko Kubo
  BMC plant biology, 20, 1, 503, 503, 03 Nov. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Cytoplasmic male sterility (CMS) is a widely used trait for hybrid seed production in many crops. Sugar beet CMS is associated with a unique mitochondrial protein named preSATP6 that forms a 250-kDa complex. Restorer-of-fertility 1 (Rf1) is a nuclear gene that suppresses CMS and is, hence, one of the targets of sugar beet breeding. Rf1 has dominant, semi-dominant and recessive alleles, suggesting that it may be a multi-allelic locus; however, the molecular basis for differences in genetic action is obscure. Molecular cloning of Rf1 revealed a gene (orf20) whose protein products produced in transgenics can bind with preSATP6 to generate a novel 200-kDa complex. The complex is also detected in fertility-restored anthers concomitant with a decrease in the amount of the 250-kDa complex. Molecular diversity of the Rf1 locus involves organizational diversity of a gene cluster composed of orf20-like genes (RF-Oma1s). We examined the possibility that members of the clustered RF-Oma1 in this locus could be associated with fertility restoration. RESULTS: Six yet uncharacterized RF-Oma1s from dominant and recessive alleles were examined to determine whether they could generate the 200-kDa complex. Analyses of transgenic calli revealed that three RF-Oma1s from a dominant allele could generate the 200-kDa complex, suggesting that clustered RF-Oma1s in the dominant allele can participate in fertility restoration. None of the three copies from two recessive alleles was 200-kDa generative. The absence of this ability was confirmed by analyzing mitochondrial complexes in anthers of plants having these recessive alleles. Together with our previous data, we designed a set of PCR primers specific to the 200-kDa generative RF-Oma1s. The amount of mRNA measured by this primer set inversely correlated with the amount of the 250-kDa complex in anthers and positively correlated with the strength of the Rf1 alleles. CONCLUSIONS: Fertility restoration by sugar beet Rf1 can involve multiple RF-Oma1s clustered in the locus, implying that stacking 200-kDa generative copies in the locus strengthens the efficacy, whereas the absence of 200-kDa generative copies in the locus makes the allele recessive irrespective of the copy number. We propose that sugar beet Rf1 is a complex locus.
• De novo transcriptome analysis reveals an unperturbed transcriptome under high cadmium conditions in the Cd-hypertolerant fern Athyrium yokoscense.
  Yuko Ukai; Komaki Inoue; Manaka Kamada; Hiroshi Teramura; Shunsuke Yanagisawa; Kazuyoshi Kitazaki; Kazuhiro Shoji; Fumiyuki Goto; Keiichi Mochida; Toshihiro Yoshihara; Hiroaki Shimada
  Genes & genetic systems, 95, 2, 65, 74, 08 Jul. 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Athyrium yokoscense shows strong tolerance to cadmium exposure, even at levels that are many times greater than the toxic levels in ordinary plants. To determine the mechanism of Cd tolerance in A. yokoscense, we grew these plants under high Cd conditions and observed the tissue-specific accumulation of Cd and generation of reactive oxygen species, which is one of the major physiological responses to Cd stress. Fuchsin staining indicated the existence of a casparian strip in A. yokoscense roots, which may participate in Cd hypertolerance in A. yokoscense. Moreover, we performed RNA-seq of RNA samples from A. yokoscense plants treated with or without Cd exposure and obtained comprehensive RNA sequences as well as the Cd-responsive expression patterns of individual genes. Through de novo transcriptome assembly and gene expression analysis, we found that A. yokoscense showed normal features with no significant change in the expression levels of any transporter genes, even under high Cd exposure conditions. Our results demonstrate that A. yokoscense has an unusual mechanism that allows the invading Cd to partition into the distal roots, thus avoiding translocation of Cd into the xylem.
• Recent advances and perspectives in plant mitochondrial biology for plant breeding
  Kubo Tomohiko; Arimura Shin-ichi; Handa Hirokazu; Koizuka Nobuya; Arakawa Takumi; Kitazaki Kazuyoshi; Kazama Tomohiko; Takenaka Mizuki; Sakamoto Wataru; Ishihara Naotada; Nakamura Takahiro; Niikura Satoshi
  Breeding Research, 22, 1, 87, 94, Japanese Society of Breeding, 2020
  Japanese
• How did a duplicated gene copy evolve into a restorer-of-fertility gene in a plant? The case of Oma1.
  Takumi Arakawa; Hajime Sugaya; Takaya Katsuyama; Yujiro Honma; Katsunori Matsui; Hiroaki Matsuhira; Yosuke Kuroda; Kazuyoshi Kitazaki; Tomohiko Kubo
  Royal Society open science, 6, 11, 190853, 190853, Nov. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Restorer-of-fertility (Rf) is a suppressor of cytoplasmic male sterility (CMS), a mitochondrion-encoded trait that has been reported in many plant species. The occurrence of CMS is considered to be independent in each lineage; hence, the question of how Rf evolved was raised. Sugar beet Rf resembles Oma1, a gene for quality control of the mitochondrial inner membrane. Oma1 homologues comprise a small gene family in the sugar beet genome, unlike Arabidopsis and other eukaryotes. The sugar beet sequence that best matched Arabidopsis atOma1 was named bvOma1; sugar beet Rf (RF1-Oma1) was another member. During anther development, atOma1 mRNA was detected from the tetrad to the microspore stages, whereas bvOma1 mRNA was detected at the microspore stage and RF1-Oma1 mRNA was detected during the meiosis and tetrad stages. A transgenic study revealed that, whereas RF1-Oma1 can bind to a CMS-specific protein and alter the higher-order structure of the CMS-specific protein complex, neither bvOma1 nor atOma1 show such activity. We favour the hypothesis that an ancestral Oma1 gene duplicated to form a small gene family, and that one of the copies evolved and acquired a novel expression pattern and protein function as an Rf, i.e. RF1-Oma1 evolved via neofunctionalization.
• Identification and characterization of a semi-dominant restorer-of-fertility 1 allele in sugar beet (Beta vulgaris).
  Takumi Arakawa; Sachiyo Ue; Chihiro Sano; Muneyuki Matsunaga; Hiroyo Kagami; Yu Yoshida; Yosuke Kuroda; Kazunori Taguchi; Kazuyoshi Kitazaki; Tomohiko Kubo
  TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik, 132, 1, 227, 240, Jan. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, KEY MESSAGE: The sugar beet Rf1 locus has a number of molecular variants. We found that one of the molecular variants is a weak allele of a previously identified allele. Male sterility (MS) caused by nuclear-mitochondrial interaction is called cytoplasmic male sterility (CMS) in which MS-inducing mitochondria are suppressed by a nuclear gene, restorer-of-fertility. Rf and rf are the suppressing and non-suppressing alleles, respectively. This dichotomic view, however, seems somewhat unsatisfactory to explain the recently discovered molecular diversity of Rf loci. In the present study, we first identified sugar beet line NK-305 as a new source of Rf1. Our crossing experiment revealed that NK-305 Rf1 is likely a semi-dominant allele that restores partial fertility when heterozygous but full fertility when homozygous, whereas Rf1 from another sugar beet line appeared to be a dominant allele. Proper degeneration of anther tapetum is a prerequisite for pollen development; thus, we compared tapetal degeneration in the NK-305 Rf1 heterozygote and the homozygote. Degeneration occurred in both genotypes but to a lesser extent in the heterozygote, suggesting an association between NK-305 Rf1 dose and incompleteness of tapetal degeneration leading to partial fertility. Our protein analyses revealed a quantitative correlation between NK-305 Rf1 dose and a reduction in the accumulation of a 250 kDa mitochondrial protein complex consisting of a CMS-specific mitochondrial protein encoded by MS-inducing mitochondria. The abundance of Rf1 transcripts correlated with NK-305 Rf1 dose. The molecular organization of NK-305 Rf1 suggested that this allele evolved through intergenic recombination. We propose that the sugar beet Rf1 locus has a series of multiple alleles that differ in their ability to restore fertility and are reflective of the complexity of Rf evolution.
• Metabolic Reprogramming in Leaf Lettuce Grown Under Different Light Quality and Intensity Conditions Using Narrow-Band LEDs.
  Kazuyoshi Kitazaki; Atsushi Fukushima; Ryo Nakabayashi; Yozo Okazaki; Makoto Kobayashi; Tetsuya Mori; Tomoko Nishizawa; Sebastian Reyes-Chin-Wo; Richard W Michelmore; Kazuki Saito; Kazuhiro Shoji; Miyako Kusano
  Scientific reports, 8, 1, 7914, 7914, 21 May 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Light-emitting diodes (LEDs) are an artificial light source used in closed-type plant factories and provide a promising solution for a year-round supply of green leafy vegetables, such as lettuce (Lactuca sativa L.). Obtaining high-quality seedlings using controlled irradiation from LEDs is critical, as the seedling health affects the growth and yield of leaf lettuce after transplantation. Because key molecular pathways underlying plant responses to a specific light quality and intensity remain poorly characterised, we used a multi-omics-based approach to evaluate the metabolic and transcriptional reprogramming of leaf lettuce seedlings grown under narrow-band LED lighting. Four types of monochromatic LEDs (one blue, two green and one red) and white fluorescent light (control) were used at low and high intensities (100 and 300 μmol·m-2·s-1, respectively). Multi-platform mass spectrometry-based metabolomics and RNA-Seq were used to determine changes in the metabolome and transcriptome of lettuce plants in response to different light qualities and intensities. Metabolic pathway analysis revealed distinct regulatory mechanisms involved in flavonoid and phenylpropanoid biosynthetic pathways under blue and green wavelengths. Taken together, these data suggest that the energy transmitted by green light is effective in creating a balance between biomass production and the production of secondary metabolites involved in plant defence.
• A fertility-restoring genotype of beet (Beta vulgaris L.) is composed of a weak restorer-of-fertility gene and a modifier gene tightly linked to the Rf1 locus.
  Takumi Arakawa; Daisuke Uchiyama; Takashi Ohgami; Ryo Ohgami; Tomoki Murata; Yujiro Honma; Hiroyuki Hamada; Yosuke Kuroda; Kazunori Taguchi; Kazuyoshi Kitazaki; Tomohiko Kubo
  PloS one, 13, 6, e0198409, 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Cytoplasmic male sterility (CMS) is a plant trait that involves interactions between nuclear- and mitochondrial genomes. In CMS, the nuclear restorer-of-fertility gene (Rf), a suppressor of male-sterility inducing mitochondria, is one of the best known genetic factors. Other unidentified genetic factors may exist but have not been well characterized. In sugar beet (Beta vulgaris L.), CMS is used for hybrid seed production, but few male-sterility inducing nuclear genotypes exist. Such genotypes could be introduced from a closely related plant such as leaf beet, but first the fertility restoring genotype of the related plant must be characterized. Here, we report the discovery of a Japanese leaf beet accession 'Fukkoku-ouba' that has both male-sterility inducing and fertility restoring genotypes. We crossed the leaf beet accession with a sugar beet CMS line, developed succeeding generations, and examined the segregation of two DNA markers that are linked to two sugar beet Rfs, Rf1 and Rf2. Only the Rf2 marker co-segregated with fertility restoration in every generation, implying that the Rf1 locus in leaf beet is occupied by a non-restoring allele. Fertility restoration was incomplete without a genetic factor closely linked to Rf1, leading to the assumption that the Rf1 locus encodes a modifier that cannot restore fertility by itself but perhaps strengthens another Rf. We sequenced the apparently non-restoring 'Fukkoku-ouba' rf1 gene-coding region and found that it closely resembles a restoring allele. The protein product demonstrated its potential to suppress CMS in transgenic suspension cells. In contrast, 'Fukkoku-ouba' rf1 transcript abundance was highly reduced compared to that of the restoring Rf1. Consistently, changes in protein complexes containing CMS-associated mitochondrial protein in anthers were very minor. Accordingly, we concluded that 'Fukkoku-ouba' rf1 is a hypomorph that acts as a non-restoring allele but has the potential to support another Rf, i.e. it is a modifier candidate.
• N2O emission from a tomato rockwool culture is highly responsive to photoirradiation conditions
  Toshihiro Yoshihara; Akio Tokura; Shin-nosuke Hashida; Kazuyoshi Kitazaki; Masaki Asobe; Koji Enbutsu; Hirokazu Takenouchi; Fumiyuki Goto; Kazuhiro Shoji
  SCIENTIA HORTICULTURAE, 201, 318, 328, Mar. 2016, [Peer-reviewed]
  English, Scientific journal
• Growth of Japanese Radish (Raphanus sativus L.) Sprouts and their Viable Bacterial Counts when Grown on Wood Pulp Medium in a Simple Cultivation System using Artificial Lighting
  WATANABE Shin-ichi; MATSUO Masanori; KITAZAKI Kazuyoshi; SAMESHIMA Kunichika; SAWAI Yusuke; MOROOKA Yuzuru; SHINOZAKI Masatoshi; TANAKA Ken-ichiro; TANAKA Tatsuya; KAWANO Tomonori; YOSHIDA Satoshi
  Shokubutsu Kankyo Kogaku, 28, 1, 29, 34, 日本生物環境工学会, 2016, [Peer-reviewed]
  Japanese, Scientific journal, In this study, we evaluated the effectiveness of wood pulp as a medium for sprout production in plant factories with artificial lighting and low-frequency manual watering. The growth of Japanese radish (Kaiware-daikon) sprouts and their viable bacterial counts when cultivated on wood pulp were compared with that of sprouts grown on urethane medium, which is conventionally used. The fresh weight and hypocotyl length of sprouts grown on wood pulp medium were greater than those of the sprouts grown on urethane medium. This is probably due to the higher water retention capacity of the pulp medium. Viable bacterial counts at packing time and after four days of storage at 5 ℃ were not significantly different between the two media at each period. Thus, we propose pulp medium as a promising alternative to urethane medium in simple systems for sprout cultivation.
• Two male sterility-inducing cytoplasms of beet (Beta vulgaris) are genetically distinct but have closely related mitochondrial genomes: implication of a substoichiometric mitochondrial DNA molecule in their evolution
  Yasuyuki Onodera; Takumi Arakawa; Rika Yui-Kurino; Masayuki P. Yamamoto; Kazuyoshi Kitazaki; Shigehiko Ebe; Muneyuki Matsunaga; Kazunori Taguchi; Yosuke Kuroda; Shiko Yamashita; Tomoyuki Sakai; Toshiro Kinoshita; Tetsuo Mikami; Tomohiko Kubo
  EUPHYTICA, 206, 2, 365, 379, Nov. 2015, [Peer-reviewed]
  English, Scientific journal
• Post-translational mechanisms are associated with fertility restoration of cytoplasmic male sterility in sugar beet (Beta vulgaris).
  Kazuyoshi Kitazaki; Takumi Arakawa; Muneyuki Matsunaga; Rika Yui-Kurino; Hiroaki Matsuhira; Tetsuo Mikami; Tomohiko Kubo
  The Plant journal : for cell and molecular biology, 83, 2, 290, 9, Jul. 2015, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Far-red light enhances removal of pericarps in tartary buckwheat (Fagopyrum tataricum Gaertn.) sprout production under artificial lighting
  Kazuyoshi Kitazaki; Shin-ichi Watanabe; Akihide Okamoto; Masanori Matsuo; Shigeki Furuya; Kunichika Sameshima
  SCIENTIA HORTICULTURAE, 185, 167, 174, Mar. 2015, [Lead author, Corresponding author]
  English, Scientific journal
• Cytoplasmic genome diversity in the cultivated apple - Short Communication
  T. Mikami; K. Kitazaki; Y. Kishima
  HORTICULTURAL SCIENCE, 42, 1, 47, 51, 2015, [Peer-reviewed]
  English, Scientific journal
• Molecular interaction between Oma1-like gene located in Rf1 locus and preSatp6 associated with sugar beet CMS
  Arakawa T; Kitazaki K; Yui-Kurino R; Mikami T; Kubo T
  Report of the Hokkaido Branch, the Japanese Society of Breeding and Hokkaido Branch, the Crop Science Society of Japan, 55, 65, 66, The Crop Science Society of Japan, Dec. 2014
  Japanese
• A kinetic analysis of cadmium accumulation in a Cd hyper-accumulator fern, Athyrium yokoscense and tobacco plants.
  Toshihiro Yoshihara; Nobuo Suzui; Satomi Ishii; Mayu Kitazaki; Haruaki Yamazaki; Kazuyoshi Kitazaki; Naoki Kawachi; Yong-Gen Yin; Sayuri Ito-Tanabata; Shin-nosuke Hashida; Kazuhiro Shoji; Hiroaki Shimada; Fumiyuki Goto; Shu Fujimaki
  Plant, cell & environment, 37, 5, 1086, 96, May 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• A precise/short-interval measurement of nitrous oxide emission from a rockwool tomato culture
  Toshihiro Yoshihara; Akio Tokura; Shin-Nosuke Hashida; Kazuyoshi Kitazaki; Masaki Asobe; Koji Enbutsu; Hirokazu Takenouchi; Fumiyuki Goto; Kazuhiro Shoji
  Environmental Control in Biology, 52, 3, 137, 147, Biotron Institute, 2014, [Peer-reviewed]
  English, Scientific journal
• Management of nitrogen fertilizer application, rather than functional gene abundance, governs nitrous oxide fluxes in hydroponics with rockwool
  Shin-nosuke Hashida; Masahumi Johkan; Kazuyoshi Kitazaki; Kazuhiro Shoji; Fumiyuki Goto; Toshihiro Yoshihara
  PLANT AND SOIL, 374, 1-2, 715, 725, Jan. 2014, [Peer-reviewed]
  English, Scientific journal
• Cytoplasmic diversity and possible maternal lineages in apples as revealed by analysis of the mitochondrial cox1 and atp9 loci
  Kazuyoshi Kitazaki; Seiya Ishigro; Sumie Kato; Akihito Wakatsuki; Yuji Kishima; Tetsuo Mikami
  SCIENTIA HORTICULTURAE, 164, 209, 212, Dec. 2013, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Identification of the predominant nonrestoring allele for Owen-type cytoplasmic male sterility in sugar beet (Beta vulgaris L.): development of molecular markers for the maintainer genotype.
  Mari Moritani; Kazunori Taguchi; Kazuyoshi Kitazaki; Hiroaki Matsuhira; Takaya Katsuyama; Tetsuo Mikami; Tomohiko Kubo
  Molecular breeding : new strategies in plant improvement, 32, 1, 91, 100, Jun. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Accelerated NAD metabolism reveals the essential role of NADH/NAD ratio on onset of senescence and carbon stock redistribution in Arabidopsis
  HASHIDA Shin‐nosuke; KITAZAKI Kazuyoshi; SHOJI Kazuhiro; GOTO Fumiyuki; YOSHIHARA Toshihiro; KAWAI‐YAMADA Maki; UCHIMIYA Hirofumi
  日本植物生理学会年会要旨集, 54th, 244, 14 Mar. 2013
  English
• NAD+ accumulation during pollen maturation in Arabidopsis regulating onset of germination.
  Shin-nosuke Hashida; Hideyuki Takahashi; Kentaro Takahara; Maki Kawai-Yamada; Kazuyoshi Kitazaki; Kazuhiro Shoji; Fumiyuki Goto; Toshihiro Yoshihara; Hirofumi Uchimiya
  Molecular plant, 6, 1, 216, 25, Jan. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Unusual and typical features of a novel restorer-of-fertility gene of sugar beet (Beta vulgaris L.).
  Hiroaki Matsuhira; Hiroyo Kagami; Masayuki Kurata; Kazuyoshi Kitazaki; Muneyuki Matsunaga; Yuko Hamaguchi; Eiki Hagihara; Minoru Ueda; Michiyo Harada; Aki Muramatsu; Rika Yui-Kurino; Kazunori Taguchi; Hideto Tamagake; Tetsuo Mikami; Tomohiko Kubo
  Genetics, 192, 4, 1347, 58, Dec. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• An apple atp9 pseudogene is maintained at high copy number in 'Golden Delicious'-type mitochondria but is present substoichiometrically in 'Delicious'-type mitochondria
  Sumie Kato; Kazuyoshi Kitazaki; Akihito Wakatsuki; Yuji Kishima; Tetsuo Mikami
  SCIENTIA HORTICULTURAE, 134, 237, 240, Feb. 2012, [Peer-reviewed]
  English, Scientific journal
• A horizontally transferred tRNA(Cys) gene in the sugar beet mitochondrial genome: evidence that the gene is present in diverse angiosperms and its transcript is aminoacylated.
  Kazuyoshi Kitazaki; Tomohiko Kubo; Hiroyo Kagami; Takuma Matsumoto; Asami Fujita; Hiroaki Matsuhira; Muneyuki Matsunaga; Tetsuo Mikami
  The Plant journal : for cell and molecular biology, 68, 2, 262, 72, Oct. 2011, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• An intact mitochondrial cox1 gene and a pseudogene with different genomic configurations are present in apple cultivars 'Golden Delicious' and 'Delicious': Evolutionary aspects
  Akihito Wakatsuki; Kazuyoshi Kitazaki; Sumie Kato; Yuji Kishima; Tetsuo Mikami
  SCIENTIA HORTICULTURAE, 130, 1, 49, 53, Aug. 2011, [Lead author]
  English, Scientific journal
• Molecular basis of cytoplasmic male sterility in beets: an overview
  Tetsuo Mikami; Masayuki P. Yamamoto; Hiroaki Matsuhira; Kazuyoshi Kitazaki; Tomohiko Kubo
  PLANT GENETIC RESOURCES-CHARACTERIZATION AND UTILIZATION, 9, 2, 284, 287, Jul. 2011, [Peer-reviewed]
  English, Scientific journal
• Mitochondrial genome diversity in Beta vulgaris L. ssp. vulgaris (Leaf and Garden Beet Groups) and its implications concerning the dissemination of the crop
  Dayou Cheng; Yu Yoshida; Kazuyoshi Kitazaki; Shinya Negoro; Hiroyuki Takahashi; Dechang Xu; Tetsuo Mikami; Tomohiko Kubo
  GENETIC RESOURCES AND CROP EVOLUTION, 58, 4, 553, 560, Mar. 2011, [Peer-reviewed]
  English, Scientific journal
• Male Sterility-Inducing Mitochondrial Genomes: How Do They Differ?
  Tomohiko Kubo; Kazuyoshi Kitazaki; Muneyuki Matsunaga; Hiroyo Kagami; Tetsuo Mikami
  CRITICAL REVIEWS IN PLANT SCIENCES, 30, 4, 378, 400, 2011, [Peer-reviewed]
  English
• A mitochondrial gene involved in cytochrome c maturation (ccmC) is expressed as a precursor with a long NH2-terminal extension in sugar beet.
  Kazuyoshi Kitazaki; Yuta Nomoto; Akihiro Aoshima; Tetsuo Mikami; Tomohiko Kubo
  Journal of plant physiology, 166, 7, 775, 80, 01 May 2009, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• The distribution of normal and male-sterile cytoplasms in Chinese sugar-beet germplasm
  Dayou Cheng; Kazuyoshi Kitazaki; Dechang Xu; Tetsuo Mikami; Tomohiko Kubo
  EUPHYTICA, 165, 2, 345, 351, Jan. 2009, [Peer-reviewed]
  English, Scientific journal
• Expression in plants of a CMS-associated gene, preSatp6, from the Owen cytoplasm of sugar beet.
  北崎一義; 野元悠太; 久保友彦; 三上哲夫
  てん菜研究会報, 46, 31, 36, May 2005, [Peer-reviewed], [Lead author]
  Japanese

• Molecular mechanism of heterosis for tolerance to low pH stress during early seedling growth in sugar beet
  山田佳奈; 小川紘生; 久野あゆみ; 須田昌義; 廣木幸太郎; 松平洋明; 北崎一義, てん菜研究会報, 65, 2025
• Genetic diversity of Japanese breeding lines in sugar beet by resequencing analysis.
  廣木幸太郎; 北崎一義; 成廣翼; 松平洋明; 久保友彦; 黒田洋輔, 日本育種学会・日本作物学会北海道談話会会報(Web), 65, 2024
• Candidates of novel restorer-of-fertility gene in sugar beet
  赤澤亨歩; 柏倉淳; 松平洋明; 北崎一義; 久保友彦, 日本育種学会・日本作物学会北海道談話会会報(Web), 65, 2024
• On the quality of beet maintainer line
  久保友彦; 織田琴子; 松平洋明; 成廣翼; 黒田洋輔; 北崎一義, 日本育種学会・日本作物学会北海道談話会会報(Web), 65, 2024
• Verification of heterosis molecular mechanism in early sugar beet growth
  大久保めぐみ; 佐藤宏亮; 久保友彦; 北崎一義, 育種学研究, 22, 2020
• テンサイの初期生育にみられるヘテロシス(雑種強勢)の網羅的な表現型解析
  大久保めぐみ; 久保友彦; 北崎一義, てん菜研究会報, 59, 2019
• テンサイ初期生育の遺伝子発現およびゲノム解析によるヘテロシス分子モデルの検証
  大久保めぐみ; 佐藤宏亮; 久保友彦; 北崎一義, 日本分子生物学会年会プログラム・要旨集(Web), 42nd, 2019
• テンサイ初期生育におけるヘテロシス(雑種強勢)の発現に関与する遺伝子群の探索
  大久保めぐみ; 佐藤宏亮; 久保友彦; 北崎一義, 日本遺伝学会大会プログラム・予稿集, 91st, 2019
• テンサイ初期生育におけるヘテロシスの表現型と遺伝子発現解析
  北崎一義; 大久保めぐみ; 久保友彦, 育種学研究, 21, 2019
• テンサイ初期生育におけるヘテロシス(雑種強勢)に関する遺伝子発現解析
  北崎一義; 大久保めぐみ; 佐藤宏亮; 久保友彦, 育種学研究, 21, 2019
• ミトコンドリアDNA相同配列を保持するテンサイ新規DNA分子の特徴付け
  北崎一義; 田添沙織; 村田智己; 伊藤栞奈; 大久保めぐみ; 栗野里香; 久保友彦, 育種学研究, 20, 2018
• ヘテロシス(雑種強勢)のオミクス解析に向けたテンサイの初期生育における表現型解析とゲノム比較
  北崎一義; 大久保めぐみ; 久保友彦, 日本植物細胞分子生物学会大会・シンポジウム講演要旨集, 36th, 2018
• 網羅的な表現型解析によって見出されたテンサイ初期生育のヘテロシス発現に関する形態的特徴
  大久保めぐみ; 久保友彦; 北崎一義, 育種学研究, 20, 2018
• テンサイ初期生育におけるヘテロシスの分子機構解明に向けたゲノム配列比較解析
  北崎一義; 大久保めぐみ; 久保友彦, 育種学研究, 20, 2018
• Morphological characteristics of heterosis during early growth in sugar beet
  大久保めぐみ; 久保友彦; 北崎一義, 日本育種学会・日本作物学会北海道談話会会報(Web), 59, 2018
• テンサイの生育初期で発現するヘテロシスの表現型解析および親系統間のゲノム配列比較
  大久保めぐみ; 久保友彦; 北崎一義, 日本分子生物学会年会プログラム・要旨集(Web), 41st, 2018
• テンサイの低化学量比ミトコンドリアDNA分子の同定と特徴づけ
  田添沙織; 村田智己; 大久保めぐみ; 久保友彦; 北崎一義, 育種学研究, 19, 2017
• テンサイ(Beta vulgaris L.)で同定された新規ミトコンドリアDNA分子の特徴と分布
  北崎一義; 田添沙織; 村田智己; 大久保めぐみ; 久保友彦, 日本生化学会大会(Web), 90th, 2017
• Identification of novel substoichiometric DNA molecule in sugar beet
  田添沙織; 村田智己; 大久保めぐみ; 栗野里香; 久保友彦; 北崎一義, 日本育種学会・日本作物学会北海道談話会会報(Web), 58, 2017

• 農業生物学特論, 2024年, 修士課程, 農学院
• 農業生物学特論演習, 2024年, 修士課程, 農学院
• 応用生命科学実験, 2024年, 学士課程, 農学部
• 応用生命科学概論, 2024年, 学士課程, 農学部
• 遺伝子制御学, 2024年, 学士課程, 農学部
• 応用生命科学演習Ⅰ, 2024年, 学士課程, 農学部
• 生物学実験, 2024年, 学士課程, 農学部

• 植物の地下部バイオマスが増大する機構の研究
  科学研究費助成事業
  27 Jun. 2025 - 31 Mar. 2028
  久保 友彦; 黒田 洋輔; 北崎 一義; 小出 陽平
  日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 25K22354
• 細胞質雄性不稔性発現における翻訳後メカニズムの研究
  科学研究費助成事業
  01 Apr. 2024 - 31 Mar. 2027
  久保 友彦; 北崎 一義; 田上 貴祥; 松平 洋明
  日本学術振興会, 基盤研究(B), 北海道大学, 24K01726
• Elucidation of the inhibitory mechanism of bolting in plants and development of bolting inhibitors
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2025
  松浦 英幸; 北岡 直樹; 久保 友彦; 黒田 洋輔; 柏木 純一; 北崎 一義; 橋本 誠
  植物の生活史には一年生、二年生、冬型一年生、多年生などがある。冬型一年生および二年生植物は、本来、夏に発芽し越冬した翌年に急激な花茎伸長（抽台）を伴う開花、種子形成を行う。よって、子孫を残す上で夏から秋の栄養成長期間中の抽台はご法度である。しかし、上記の植物が生活環を完結させるために必須な『抽台抑制』に関しては、その抑制機構の詳細が明らかでない。よって、低分子量の生理活性物質の関与を想定し研究を進めている。本研究での実施の項目は【A】ABCの葉部から茎頂部への移動、【B】植物に存在するABC関連物質の探索、【C】ABCを受容するタンパク質とその機能、【D】シロイヌナズナ抽台誘導に関与する、ABC分解酵素をコードする遺伝子の探索、【E】早抽性および晩抽性ビートにおける遺伝子特性、【F】実農業で利用可能な、栄養成長期の抽台を抑制する植物化学調節剤の開発である。項目Aについては候補の化合物の合成に成功し、ラベルパターンの異なる化合物の合成に必要な合成方法を考案しているところである。項目Bについては、関連の化合物の単離精製、構造決定に成功し、英字の論文とした。項目Cについては、候補タンパクを釣り上げるための化合物の合成を進めている。項目D、Eについてはシロイヌナズナから選られたRNAseqデータをビートに当てはめ、相応の遺伝子を見つけつつある。項目Fについて昨年とほぼ同様な圃場実験を進めているが改良法が望まれるデータであった。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 23K23534
• 初期生育におけるヘテロシス（雑種強勢）の発現機構の解明と育種利用
  科学研究費助成事業 基盤研究(C)
  01 Apr. 2022 - 31 Mar. 2025
  北崎 一義; 松平 洋明
  日本学術振興会, 基盤研究(C), 北海道大学, 22K05569
• 細胞質雄性不稔性を温度感受性化する稔性回復遺伝子の育種学的研究
  科学研究費助成事業 基盤研究(B)
  01 Apr. 2021 - 31 Mar. 2024
  久保 友彦; 北崎 一義; 松平 洋明
  温度感受性の稔性回復遺伝子（Rf）を保持するテンサイ個体を用いて、その形質発現に関わる研究を行った。温度感受性の稔性回復遺伝子（Rf）を保持するテンサイは高温に反応して雄性不稔化することはわかっていたが、最短の処理時間については不明であった。予備的な調査であるが、１時間でも効果があることを示唆するデータを得た。また、処理温度については30度でも十分である可能性がでてきた。このことは、この遺伝子を使った育種システムを構築するにあたって好都合である。温度感受性Rfを培養細胞で発現させ、相互作用するタンパク質があるかどうか調べた。導入遺伝子にFLAGタグを付加して免疫沈降実験を行った。その結果、共免疫沈降するいくつかの候補タンパク質を銀染色したゲル上で発見したが、同程度の分子量を持つタンパク質バンドが存在するため、同定には至らなかった。分子量に基づき、いくつかの候補タンパク質をあげることはできた。新規の温度感受性Rfの染色体マッピングを行った。次世代ゲノム解析的手法を用いていくつかの分離集団を調べたところ、上記のRfとは異なる連鎖群にマップされた。座乗位置より、これまで解析が進んでいなかったRfの対立遺伝子ではないかと思われる。この染色体領域のRfについては、連鎖する2因子であるというモデルが出されていたが、確証は得られていなかった。今回得たデータは、このモデルを支持する可能性がある。野外における形質発現を調べる予備調査として、礼文島と久留米市において、テンサイを開花できることがわかった。
  日本学術振興会, 基盤研究(B), 北海道大学, 21H02159
• Study on the cytoplasmic male sterility expression using incomplete dominance alleles of restorer of fertility gene
  Grants-in-Aid for Scientific Research
  01 Apr. 2018 - 31 Mar. 2021
  Kubo Tomohiko
  Cytoplasmic male sterility (CMS) is encoded by mitochondrial genome. Its expression is controlled by nuclear restorer-of-fertility gene (Rf). Analyses of plant genome sequences suggested multiple allelism of Rf locus. This possibility was investigated in sugar beet, and alleles with various strength were found. Plants with CMS mitochondria and Rf alleles with different strength were compared. Anther morphology differed in accordance with the level of MS expression. Mitochondria exhibited morphological abnormality. Difference in gene expression profile was also detected.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 18K05564
• Study on identification of genes associated with heterosis and application for breeding.
  Grants-in-Aid for Scientific Research
  01 Apr. 2017 - 31 Mar. 2020
  Kitazaki Kazuyoshi
  Heterosis, which is phenomenon that progeny of varieties of species exhibit greater various traits than both parents, contributes to produce crops in high yields. However, mechanisms of heterosis remain unclear. This study analyzed expression of heterosis in sugar beet during early growth. Phenotypic investigation showed that almost all traits related to biomass of F1 were higher than those of both parents and cell size likely contribute to increase biomass in tap roots. Relative growth rate is higher in F1 than in parents. As the results of gene expression analysis by RNA-seq in leaf and tap root, no up-regulation of metabolic pathways explained that biomass of F1 more increased. These results suggested that there are many genes related to heterosis in sugar beet during early growth.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University, 17K15207
• テンサイの雑種強勢発現に寄与するQTL（量的形質遺伝子座）の遺伝解析
  研究助成(奨励)
  Sep. 2018 - Mar. 2019
  北崎 一義
  秋山記念生命科学振興財団, Principal investigator, Competitive research funding

• 植物工場
  Patent right, 北崎 一義, 国立研究開発法人農業・食品産業技術総合研究機構
  特願2016-143941, 22 Jul. 2016
  特開2018-011564, 25 Jan. 2018
  201803014840564726
• 光によるコマツナのカルシウム増大方法
  Patent right, 北▲崎▼ 一義; 庄子 和博, 一般財団法人電力中央研究所
  特願2012-089240, 10 Apr. 2012
  特開2013-215145, 24 Oct. 2013
  特許第6304919号
  201303030308074131