2005, 平成17年度日本育種学会奨励賞　　　　　　　　　　　　　　　
Japan

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, Springer Science and Business Media LLC, 05 Jan. 2026, [Peer-reviewed], [International Magazine]
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, e0332940, Public Library of Science (PLoS), 23 Sep. 2025, [Peer-reviewed], [Last author, Corresponding author]
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.

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, [Peer-reviewed], [International Magazine]
English, Scientific journal

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, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, 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.

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, 219, 11, Springer Science and Business Media LLC, 10 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.)
Eigo Taniguchi, Kosuke Satoh, Megumi Ohkubo, Sachiyo Ue, Hiroaki Matsuhira, Yosuke Kuroda, Tomohiko Kubo, Kazuyoshi Kitazaki
PLOS ONE, 18, 8, e0285430, e0285430, Public Library of Science (PLoS), 08 Aug. 2023, [Peer-reviewed], [International Magazine]
English, Scientific journal, Heteroplasmy, the coexistence of multiple mitochondrial DNA (mtDNA) sequences in a cell, is well documented in plants. Next-generation sequencing technology (NGS) has made it feasible to sequence entire genomes. Thus, NGS has the potential to detect heteroplasmy; however, the methods and pitfalls in heteroplasmy detection have not been fully investigated and identified. One obstacle for heteroplasmy detection is the sequence homology between mitochondrial-, plastid-, and nuclear DNA, of which the influence of nuclear DNA segments homologous to mtDNA (numt) need to be minimized. To detect heteroplasmy, we first excluded nuclear DNA sequences of sugar beet (Beta vulgaris) line EL10 from the sugar beet mtDNA sequence. NGS reads were obtained from single plants of sugar beet lines NK-195BRmm-O and NK-291BRmm-O and mapped to the unexcluded mtDNA regions. More than 1000 sites exhibited intra-individual polymorphism as detected by genome browsing analysis. We focused on a 309-bp region where 12 intra-individual polymorphic sites were closely linked to each other. Although the existence of DNA molecules having variant alleles at the 12 sites was confirmed by PCR amplification from NK-195BRmm-O and NK-291BRmm-O, these variants were not always called by six variant-calling programs, suggesting that these programs are inappropriate for intra-individual polymorphism detection. When we changed the nuclear DNA reference, a numt absent from EL10 was found to include the 309-bp region. Genetic segregation of an F₂ population from NK-195BRmm-O x NK-291BRmm-O supported the numt origin of the variant alleles. Using four references, we found that numt detection exhibited reference dependency, and extreme polymorphism of numts exists among sugar beet lines. One of the identified numts absent from EL10 is also associated with another intra-individual polymorphic site in NK-195mm-O. Our data suggest that polymorphism among numts is unexpectedly high within sugar beets, leading to confusion about the true degree of heteroplasmy.

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
Theoretical and Applied Genetics, 135, 5, 1457, 1466, Springer Science and Business Media LLC, 11 Feb. 2022, [Peer-reviewed], [Last author], [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, 69, 1, 271, 283, Jan. 2022, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
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], [Last author, Corresponding author], [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, Springer Science and Business Media LLC, Dec. 2020, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal,


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.





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.





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.

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], [Last author, Corresponding author], [International Magazine]
English, Scientific journal

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
Theoretical and Applied Genetics, 132, 1, 227, 240, Springer Science and Business Media LLC, Jan. 2019, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal, 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.

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, e0198409, Public Library of Science (PLoS), 01 Jun. 2018, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal

Efficient callus formation and plant regeneration are heritable characters in sugar beet (Beta vulgaris L.)
Hiroyo Kagami, Kazunori Taguchi, Takumi Arakawa, Yosuke Kuroda, Hideto Tamagake, Tomohiko Kubo
Hereditas, 153, 1, Dec. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal

Identification of molecular variants of the nonrestoring restorer-of-fertility 1 allele in sugar beet (Beta vulgaris L.)
Takashi Ohgami, Daisuke Uchiyama, Sachiyo Ue, Rika Yui-Kurino, Yu Yoshida, Yoko Kamei, Yosuke Kuroda, Kazunori Taguchi, Tomohiko Kubo
Theoretical and Applied Genetics, 129, 4, 675, 688, Apr. 2016, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
English, Scientific journal

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
PLANT JOURNAL, 83, 2, 290, 299, Jul. 2015, [Peer-reviewed]
English, Scientific journal

Molecular mapping of restorer-of-fertility 2 gene identified from a sugar beet (Beta vulgaris L. ssp vulgaris) homozygous for the non-restoring restorer-of-fertility 1 allele
Yujiro Honma, Kazunori Taguchi, Hajime Hiyama, Rika Yui-Kurino, Tetsuo Mikami, Tomohiko Kubo
THEORETICAL AND APPLIED GENETICS, 127, 12, 2567, 2574, Dec. 2014, [Peer-reviewed]
English, Scientific journal

Hybrid Breeding Skewed the Allelic Frequencies of Molecular Variants Derived from the Restorer of fertility 1 Locus for Cytoplasmic Male Sterility in Sugar Beet (Beta vulgaris L.)
Kazunori Taguchi, Hajime Hiyama, Rika Yui-Kurino, Aki Muramatsu, Tetsuo Mikami, Tomohiko Kubo
CROP SCIENCE, 54, 4, 1407, 1412, Jul. 2014, [Peer-reviewed]
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, 32, 1, 91, 100, Jun. 2013, [Peer-reviewed]
English, Scientific journal

Evolutionary aspects of a unique internal mitochondrial targeting signal in nuclear-migrated rps19 of sugar beet (Beta vulgaris L.)
Muneyuki Matsunaga, Yoshiya Takahashi, Rika Yui-Kurino, Tetsuo Mikami, Tomohiko Kubo
GENE, 517, 1, 19, 26, Mar. 2013, [Peer-reviewed]
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, +, Dec. 2012, [Peer-reviewed]
English, Scientific journal

Mitochondrial minisatellite polymorphisms in fodder and sugar beets reveal genetic bottlenecks associated with domestication
Y. Yoshida, M. Matsunaga, D. Cheng, D. Xu, Y. Honma, T. Mikami, T. Kubo
BIOLOGIA PLANTARUM, 56, 2, 369, 372, Jun. 2012, [Peer-reviewed]
English, Scientific journal

Is RNA editing implicated in group II intron survival in the angiosperm mitochondrial genome?
Hiroyo Kagami, Hironori Nagano, Yoshiya Takahashi, Tetsuo Mikami, Tomohiko Kubo
GENOME, 55, 1, 75, 79, Jan. 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
PLANT JOURNAL, 68, 2, 262, 272, Oct. 2011, [Peer-reviewed]
English, Scientific journal

Identification and Precise Mapping of Resistant QTLs of Cercospora Leaf Spot Resistance in Sugar Beet (Beta vulgaris L.)
Kazunori Taguchi, Tomohiko Kubo, Hiroyuki Takahashi, Hideyuki Abe
G3-GENES GENOMES GENETICS, 1, 4, 283, 291, Sep. 2011, [Peer-reviewed]
English, Scientific journal

Polymorphic minisatellites in the mitochondrial DNAs of Oryza and Brassica
Yujiro Honma, Yu Yoshida, Toru Terachi, Kinya Toriyama, Tetsuo Mikami, Tomohiko Kubo
CURRENT GENETICS, 57, 4, 261, 270, Aug. 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

Large 3' UTR of sugar beet rps3 is truncated in cytoplasmic male-sterile mitochondria
Muneyuki Matsunaga, Hironori Nagano, Tetsuo Mikami, Tomohiko Kubo
PLANT CELL REPORTS, 30, 2, 231, 238, Feb. 2011, [Peer-reviewed]
English, Scientific journal

Increased accumulation of intron-containing transcripts in rice mitochondria caused by low temperature: is cold-sensitive RNA editing implicated?
Shiho Kurihara-Yonemoto, Tomohiko Kubo
CURRENT GENETICS, 56, 6, 529, 541, Dec. 2010, [Peer-reviewed]
English, Scientific journal

Molecular mapping of a gene conferring resistance to Aphanomyces root rot (black root) in sugar beet (Beta vulgaris L.)
Kazunori Taguchi, Kazuyuki Okazaki, Hiroyuki Takahashi, Tomohiko Kubo, Tetsuo Mikami
EUPHYTICA, 173, 3, 409, 418, Jun. 2010, [Peer-reviewed]
English, Scientific journal

A new source of cytoplasmic male sterility found in wild beet and its relationship to other CMS types
Yuki Kawanishi, Hiroshi Shinada, Muneyuki Matsunaga, Yusuke Masaki, Tetsuo Mikami, Tomohiko Kubo
GENOME, 53, 4, 251, 256, Apr. 2010, [Peer-reviewed]
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

Quantitative trait locus responsible for resistance to Aphanomyces root rot (black root) caused by Aphanomyces cochlioides Drechs. in sugar beet
Kazunori Taguchi, Naoki Ogata, Tomohiko Kubo, Shinji Kawasaki, Tetsuo Mikami
THEORETICAL AND APPLIED GENETICS, 118, 2, 227, 234, Jan. 2009, [Peer-reviewed]
English, Scientific journal

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, 780, 2009, [Peer-reviewed]
English, Scientific journal

A male sterility-associated mitochondrial protein in wild beets causes pollen disruption in transgenic plants
Masayuki P. Yamamoto, Hiroshi Shinada, Yasuyuki Onodera, Chihiro Komaki, Tetsuo Mikami, Tomohiko Kubo
PLANT JOURNAL, 54, 6, 1027, 1036, Jun. 2008, [Peer-reviewed]
English, Scientific journal

Mitochondrial DNA phylogeny of cultivated and wild beets: Relationships among cytoplasmic male-sterility-inducing and nonsterilizing cytoplasms
Satsuki Nishizawa, Tetsuo Mikami, Tomohiko Kubo
GENETICS, 177, 3, 1703, 1712, Nov. 2007, [Peer-reviewed]
English, Scientific journal

An anther-specific lipid transfer protein gene in sugar beet: its expression is strongly reduced in male-sterile plants with Owen cytoplasm
Hiroaki Matsuhira, Hiroshi Shinada, Rika Yui-Kurino, Naonori Hamato, Mitsuhiro Umeda, Tetsuo Mikami, Tomohiko Kubo
PHYSIOLOGIA PLANTARUM, 129, 2, 407, 414, Feb. 2007, [Peer-reviewed]
English, Scientific journal

The Owen mitochondrial genome in sugar beet (Beta vulgaris L.): possible mechanisms of extensive rearrangements and the origin of the mitotype-unique regions
Mizuho Satoh, Tomohiko Kubo, Tetsuo Mikami
THEORETICAL AND APPLIED GENETICS, 113, 3, 477, 484, Aug. 2006, [Peer-reviewed]
English, Scientific journal

Sugar beet BAC library construction and assembly of a contig spanning Rf1, a restorer-of-fertility gene for Owen cytoplasmic male sterility
E Hagihara, H Matsuhira, M Ueda, T Mikami, T Kubo
MOLECULAR GENETICS AND GENOMICS, 274, 3, 316, 323, Oct. 2005, [Peer-reviewed]
English, Scientific journal

Molecular mapping of a fertility restorer gene for Owen cytoplasmic male sterility in sugar beet
E Hagihara, N Itchoda, Y Habu, S Iida, T Mikami, T Kubo
THEORETICAL AND APPLIED GENETICS, 111, 2, 250, 255, Jul. 2005, [Peer-reviewed]
English, Scientific journal

The 5'-leader sequence of sugar beet mitochondrial atp6 encodes a novel polypeptide that is characteristic of Owen cytoplasmic male sterility
MP Yamamoto, T Kubo, T Mikami
MOLECULAR GENETICS AND GENOMICS, 273, 4, 342, 349, Jun. 2005, [Peer-reviewed]
English, Scientific journal

The cytoplasmic male-sterile type and normal type mitochondrial genomes of sugar beet share the same complement of genes of known function but differ in the content of expressed ORFs
M Satoh, T Kubo, S Nishizawa, A Estiati, N Itchoda, T Mikami
MOLECULAR GENETICS AND GENOMICS, 272, 3, 247, 256, Oct. 2004, [Peer-reviewed]
English, Scientific journal

Antisense inhibition of mitochondrial pyruvate dehydrogenase E1 alpha subunit in anther tapetum causes male sterility
R Yui, S Iketani, T Mikami, T Kubo
PLANT JOURNAL, 34, 1, 57, 66, Apr. 2003, [Peer-reviewed]
English, Scientific journal

The rps4 gene in sugar beet mitochondria: insertion/deletion mutations occur within the gene but do not disrupt the reading frame
N Itchoda, T Kubo, A Estiati, MP Yamamoto, H Handa, T Mikami
JOURNAL OF PLANT PHYSIOLOGY, 159, 2, 211, 215, Feb. 2002, [Peer-reviewed]
English, Scientific journal

The sugar beet mitochondrial nad4 gene: an intron loss and its phylogenetic implication in the Caryophyllales
N Itchoda, S Nishizawa, H Nagano, T Kubo, T Mikami
THEORETICAL AND APPLIED GENETICS, 104, 2-3, 209, 213, Feb. 2002, [Peer-reviewed]
English, Scientific journal

The complete nucleotide sequence of the mitochondrial genome of sugar beet (Beta vulgaris L.) reveals a novel gene for tRNA(Cys)(GCA)
T Kubo, S Nishizawa, A Sugawara, N Itchoda, A Estiati, T Mikami
NUCLEIC ACIDS RESEARCH, 28, 13, 2571, 2576, Jul. 2000, [Peer-reviewed]
English, Scientific journal

The nad4L-orf25 gene cluster is conserved and expressed in sugar beet mitochondria
T Kubo, MP Yamamoto, T Mikami
THEORETICAL AND APPLIED GENETICS, 100, 2, 214, 220, Jan. 2000, [Peer-reviewed]
English, Scientific journal

Variable number of tandem repeat loci in the mitochondrial genomes of beets
S Nishizawa, T Kubo, T Mikami
CURRENT GENETICS, 37, 1, 34, 38, Jan. 2000, [Peer-reviewed]
English, Scientific journal

Heterogeneity of the atp6 presequences in normal and different sources of male-sterile cytoplasms of sugar beet
Y Onodera, MP Yamamoto, T Kubo, T Mikami
JOURNAL OF PLANT PHYSIOLOGY, 155, 4-5, 656, 660, Oct. 1999, [Peer-reviewed]
English, Scientific journal

Alterations in organization and transcription of the mitochondrial genome of cytoplasmic male sterile sugar beet (Beta vulgaris L.)
T Kubo, S Nishizawa, T Mikami
MOLECULAR AND GENERAL GENETICS, 262, 2, 283, 290, Sep. 1999, [Peer-reviewed]
English, Scientific journal

The ribosomal protein S7 gene is transcribed and edited in sugar beet mitochondria
A. Estiati, T. Kubo, Mikami
Physiologia Plantarum, 102, 2, 325, 327, Feb. 1998, [Peer-reviewed]
English, Scientific journal

A duplicated sequence in sugarbeet mitochondrial transcripts is differentially edited: Analysis of orfB and its derivative orf324 mRNAs
T Kubo, T Mikami
BIOCHIMICA ET BIOPHYSICA ACTA-GENE STRUCTURE AND EXPRESSION, 1307, 3, 259, 262, Jul. 1996, [Peer-reviewed]
English, Scientific journal

PHYSICAL AND GENE ORGANIZATION OF MITOCHONDRIAL-DNA FROM THE FERTILE CYTOPLASM OF SUGAR-BEET (BETA-VULGARIS L)
T KUBO, YS TAKATO, T KINOSHITA, T MIKAMI
CURRENT GENETICS, 28, 3, 235, 241, Aug. 1995, [Peer-reviewed]
English, Scientific journal

THE CHLOROPLAST TRNP-TRNW-PETG GENE-CLUSTER IN THE MITOCHONDRIAL GENOMES OF BETA-VULGARIS, B-TRIGYNA AND B-WEBBIANA - EVOLUTIONARY ASPECTS
T KUBO, Y YANAI, T KINOSHITA, T MIKAMI
CURRENT GENETICS, 27, 3, 285, 289, Feb. 1995, [Peer-reviewed]
English, Scientific journal

Physical maps of mitochondrial genomes from male-fertile and male-sterile sugar beets
T Kinoshita, T Mikami, T Kubo
CURRENT ISSUES IN PLANT MOLECULAR AND CELLULAR BIOLOGY, 22, 303, 308, 1995, [Peer-reviewed]
English, International conference proceedings

THE SUGAR-BEET MITOCHONDRIAL GENOME CONTAINS AN ORF SHARING SEQUENCE HOMOLOGY WITH THE GENE FOR THE 30 KDA SUBUNIT OF BOVINE MITOCHONDRIAL COMPLEX-I
T KUBO, T MIKAMI, T KINOSHITA
MOLECULAR & GENERAL GENETICS, 241, 3-4, 479, 482, Nov. 1993, [Peer-reviewed]
English, Scientific journal

未来のテンサイ遺伝育種学に必要なこと　　　　　　　　　　　　　　　
久保友彦, グリーンテクノ情報, 19, 1, Jun. 2023, [Invited], [Lead author, Last author, Corresponding author], [Domestic magazines]
Japanese, Others

ガーデンビートはオリゴ糖原料作物になりうるか：てん菜との関係から考える
久保友彦, 早川諒, 森 春英, 月報 砂糖類・でん粉情報, 49, 54, Mar. 2022, [Invited], [Lead author], [Domestic magazines]
独立行政法人 農畜産業振興機構, Japanese, Introduction commerce magazine

Recent advances and perspectives in plant mitochondrial biology for plant breeding
Tomohiko Kubo, Takumi Arakawa, Kazuyoshi Kitazaki, Tomohiko Kazama, Mizuki Takenaka, Wataru Sakamoto, Naotada Ishihara, Takahiro Nakamura, Satoshi Niikura, Shin-ichi Arimura, Hirokazu Handa, Nobuya Koizuka, Breeding Research, 22, 1, 87, 94, 01 Jun. 2020, [Domestic magazines]
Japanese Society of Breeding, Japanese, Introduction scientific journal

What Does the Molecular Genetics of Different Types of Restorer-of-Fertility Genes Imply?
Tomohiko Kubo, Takumi Arakawa, Yujiro Honma, Kazuyoshi Kitazaki, Plants, 9, 3, 361, 361, 13 Mar. 2020, [Peer-reviewed], [Invited], [Lead author, Corresponding author], [International Magazine]
Cytoplasmic male sterility (CMS) is a widely used trait for hybrid seed production. Although male sterility is caused by S cytoplasm (male-sterility inducing mitochondria), the action of S cytoplasm is suppressed by restorer-of-fertility (Rf), a nuclear gene. Hence, the genetics of Rf has attained particular interest among plant breeders. The genetic model posits Rf diversity in which an Rf specifically suppresses the cognate S cytoplasm. Molecular analysis of Rf loci in plants has identified various genes; however, pentatricopeptide repeat (PPR) protein (a specific type of RNA-binding protein) is so prominent as the Rf-gene product that Rfs have been categorized into two classes, PPR and non-PPR. In contrast, several shared features between PPR- and some non-PPR Rfs are apparent, suggesting the possibility of another grouping. Our present focus is to group Rfs by molecular genetic classes other than the presence of PPRs. We propose three categories that define partially overlapping groups of Rfs: association with post-transcriptional regulation of mitochondrial gene expression, resistance gene-like copy number variation at the locus, and lack of a direct link to S-orf (a mitochondrial ORF associated with CMS). These groups appear to reflect their own evolutionary background and their mechanism of conferring S cytoplasm specificity., MDPI AG, English, Introduction scientific journal

2018年第60回シンポジウム（シンポジウム・ワークショップ）報告について
久保 友彦, 育種学研究, 21, 1, 47, 48, 2019, [Invited], [Domestic magazines]
Japanese, Meeting report

ビーツはどこしゅっしんなんですか　　　　　　　　　　　　　　　
久保 友彦, 日本の学童ほいく, 515, 7月号, 39, Jun. 2018, [Invited], [Lead author, Corresponding author], [Domestic magazines]
Japanese, Introduction commerce magazine

農学校1年1組 てん菜の時間 ビートの種類と栽培の歴史　　　　　　　　　　　　　　　
久保 友彦, ニューカントリー, 65, 2月号, 48, 49, Feb. 2018, [Invited], [Lead author, Corresponding author], [Domestic magazines]
Japanese, Introduction commerce magazine

Sugar beet (Beta vulgaris L.)
Hiroyo Kagami, Masayuki Kurata, Hiroaki Matsuhira, Kazunori Taguchi, Tetsuo Mikami, Hideto Tamagake, Tomohiko Kubo, Agrobacterium Protocols: Third Edition, 1, 335, 347, 09 Oct. 2014, [Peer-reviewed]
Springer New York, English

Are mitochondria obedent organelles?: what the recent studies tell us about nuclear-mitochondrial interaction
Tomohiko Kubo, Toru Terachi, Breeding Research, 15, 2, 68, 71, 2013, [Invited]
Japanese Society of Breeding, Japanese, Introduction scientific journal

Erratum: Is RNA editing implicated in group II intron survival in the angiosperm mitochondrial genome? (Genome (2012) 55:1 (75-79))
Hiroyo Kagami, Hironori Nagano, Yoshiya Takahashi, Tetsuo Mikami, Tomohiko Kubo, Genome, 55, 6, 481, Jun. 2012, [Peer-reviewed]
English

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, Introduction 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, Book review

Cost of having the largest mitochondrial genome: evolutionary mechanism of plant mitochondrial genome　　　　　　　　　　　　　　　
Kitazaki K, Kubo T, Journal of Botany, 2010, 620137, 2010, [Peer-reviewed]
English, Introduction scientific journal

Angiosperm mitochondrial genomes and mutations
Tomohiko Kubo, Kathleen J. Newton, MITOCHONDRION, 8, 1, 5, 14, Jan. 2008, [Peer-reviewed]
English, Introduction scientific journal

Organization and variation of angiosperm mitochondrial genome
Tomohiko Kubo, Tetsuo Mikami, PHYSIOLOGIA PLANTARUM, 129, 1, 6, 13, Jan. 2007, [Peer-reviewed]
English, Book review

ミトコンドリアゲノムと細胞質雄性不稔性　　　　　　　　　　　　　　　
久保 友彦, 育種学研究, 8, 135, 141, 2006, [Invited]
Japanese, Introduction scientific journal

[Nuclear-mitochondrial interaction changes sex expression in higher plants: cytoplasmic male sterility and restorer-offertility gene].
Kubo T, Mikami T, Tanpakushitsu kakusan koso. Protein, nucleic acid, enzyme, 50, 1803, 1807, Nov. 2005, [Invited]
14 Suppl, Japanese, Introduction commerce magazine

アゼルバイジャンに自生するBeta lomatogonaについて
久保 友彦, 田口 和憲, てん菜研究会報 = Proceedings of the Sugar Beet Research Association, 45, 41, 43, May 2004
甘味資源振興会, Japanese

Collaborative collection of Beta genetic resources in Russia and Azerbaijan, 2003　　　　　　　　　　　　　　　
田口和憲, 久保友彦, Burenin VI, Burmistrov LA、Akparov Z、Alderov AA, Annual Report on Exploration and Introduction of Plant Genetic Resources, 20, 93, 101, 2004
Japanese, Others

アゼルバイジャンを知るための67章
久保, 友彦, 第3章 地理・気候・自然--アゼルバイジャンと植物遺伝資源
明石書店, Aug. 2018, 9784750346724, 426p, 28-32, Japanese, General book, [Contributor]

Frontiers of Agricultural Science　　　　　　　　　　　　　　　
KUBO Tomohiko, Sugar beet
Shoukadoh Book Sellers, 2015, 9784879746856, [Contributor]

Agricultural Sciences for Human Sustainability (Graduate School of Agriculture, Hokkaido University Editorial Committee)　　　　　　　　　　　　　　　
Kubo T, Horizontal gene transfer to the plant mitochondrial genome
Kaiseisha Press, 2012, [Contributor]

コーカサスを知るための60章（北川誠一，前田弘毅，廣瀬陽子，吉村貴之 編著）　　　　　　　　　　　　　　　
久保 友彦, 栽培植物起原地としてのコーカサス
2006, 4750323012, 336, 23-26, Japanese, General book, [Contributor]

植物育種学辞典（日本育種学会 編）　　　　　　　　　　　　　　　
久保 友彦, 「IPCR」，「RT-PCR」，「Rループ」，「塩基」，「相補性」，「DNA」，「DNA分解酵素」，「TAIL-PCR」，「Dループ」，「トポイソメラーゼ」，「ヌクレアーゼ」，「ヌクレオシド」，「ヌクレオチド」，「PCR法」，「ピリミジン塩基」，「プリン塩基」
培風館, 2005, [Contributor]

Structure of mitochondrial genomes of Beta vulgaris and B. maritima　　　　　　　　　　　　　　　
Kubo T, Inoue M, Nishizawa S, Mikami T, Structure of mitochondrial genomes of Beta vulgaris and B. maritima
Backhuys Publishers, 1998, [Contributor]