Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Enhanced ovary abscission after pollination and hybrid seed lethality result in post-zygotic reproductive isolation in plant interspecific crosses. However, the connection between these barriers remains unclear. Here, we report that an imbalance in parental genomes or endosperm balance number (EBN) causes hybrid seed lethality and ovary abscission in both interspecific and intraspecific-interploidy crosses in the genus Nicotiana. Auxin treatment suppressed ovary abscission, but not hybrid seed lethality, in an interspecific cross between Nicotiana suaveolens and N. tabacum, suggesting that ovary abscission-related genes are located downstream of those involved in hybrid seed lethality. We performed interploidy crosses among N. suaveolens tetraploids, octoploids, and neopolyploids and revealed hybrid seed lethality and ovary abscission in interploid crosses. Furthermore, a higher maternal EBN than paternal EBN caused these barriers, as previously observed in N. suaveolens × N. tabacum crosses. Altogether, these results suggest that maternal excess of EBN causes hybrid seed lethality, which in turn leads to ovary abscission through the same mechanism in both interspecific and interploidy crosses.

DOI： 10.3389/fpls.2022.899206

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1007/s11032-022-01279-8

PubMed

Other URL： https://link.springer.com/article/10.1007/s11032-022-01279-8/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

<jats:p>Wild tobacco species in the Nicotiana section Suaveolentes are promising genetic resources to introduce their disease resistance to cultivated tobacco, Nicotiana tabacum. However, hybrid lethality is observed in hybrid seedlings from crosses between most Suaveolentes species and N. tabacum. In particular, N. benthamiana belonging to the section Suaveolentes produces only viable hybrids after crossing with N. tabacum. In the present study, crossability between N. benthamiana and N. excelsior (section Suaveolentes) was investigated to test the possible usefulness of N. benthamiana as the bridge parent to transfer desirable genes of N. excelsior to N. tabacum via bridge crossing. After reciprocal crosses using three accessions of N. benthamiana and N. excelsior each, several crossing barriers such as cross-incompatibility, seed abortion, and male and female hybrid sterility were observed. Although reciprocal hybrids between N. benthamiana and N. excelsior showed a high degree of chromosome pairing in meiosis, univalents and multivalents, as well as chromosome bridges and lagging chromosomes, were observed. These meiotic abnormalities were thought to cause hybrid sterility. The possible usefulness of reciprocal hybrids between N. benthamiana and N. excelsior is discussed.</jats:p>

DOI： 10.3390/agronomy11122583

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

In plants, F1 hybrids showing hybrid weakness exhibit weaker growth than their parents. The phenotypes of hybrid weakness are often suppressed at certain temperatures. However, it is unclear whether hybrid weakness in Capsicum annuum × C. chinense is temperature-dependent or not. Our study showed that Capsicum hybrid weakness was suppressed at 30 and 35 °C and was induced at 15, 20, and 25 °C. Moreover, we investigated the time course of hybrid weakness in cell death, metabolite content, and gene expression in leaves of plants transferred to 20 °C after growing at 30 °C for 21 days. The expression of pathogen defense-related genes was upregulated at 1 day after transfer to 20 °C (DAT). Cell death was detected at 7 DAT, plant growth had almost stopped since 14 DAT, and sugars were accumulated at 42 DAT in hybrid plants. The study revealed that some sugar transporter genes, which had been upregulated since 7 DAT, were involved in sugar accumulation in Capsicum hybrid weakness. Thus, our results demonstrated that gene expression changes occur first, followed by physiological and morphological changes after induction of hybrid weakness. These responses observed in this study in Capsicum hybrid weakness are likely to be owed to plant defense responses-like reactions.

DOI： 10.1007/s10265-021-01340-1

PubMed

Other URL： https://link.springer.com/article/10.1007/s10265-021-01340-1/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Hybrid lethality, a postzygotic mechanism of reproductive isolation, is a phenomenon that causes the death of F1 hybrid seedlings. Hybrid lethality is generally caused by the epistatic interaction of two or more loci. In the genus Nicotiana, N. debneyi has the dominant allele Hla1-1 at the HLA1 locus that causes hybrid lethality in F1 hybrid seedlings by interaction with N. tabacum allele(s). Here, we mapped the HLA1 locus using the F2 population segregating for the Hla1-1 allele derived from the interspecific cross between N. debneyi and N. fragrans. To map HLA1, several DNA markers including random amplified polymorphic DNA, amplified fragment length polymorphism, and simple sequence repeat markers, were used. Additionally, DNA markers were developed based on disease resistance gene homologs identified from the genome sequence of N. benthamiana. Linkage analysis revealed that HLA1 was located between two cleaved amplified polymorphic sequence markers Nb14-CAPS and NbRGH1-CAPS at a distance of 10.8 and 10.9 cM, respectively. The distance between these markers was equivalent to a 682 kb interval in the genome sequence of N. benthamiana.

DOI： 10.3390/plants10102062

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

<title>Abstract</title>Hybrid lethality, meaning the death of F₁ hybrid seedlings, has been observed in many plant species, including <italic>Nicotiana</italic>. Previously, we have revealed that hybrids of the selected <italic>Nicotiana occidentalis</italic> accession and <italic>N. tabacum</italic>, an allotetraploid with S and T genomes, exhibited lethality characterized by the fading of shoot color. The lethality was suggested to be controlled by alleles of loci on the S and T genomes derived from <italic>N. sylvestris</italic> and <italic>N. tomentosiformis</italic>, respectively. Here, we extended the analysis of hybrid lethality using other two accessions of <italic>N. occidentalis</italic> identified from the five tested accessions. The two accessions were crossed with <italic>N. tabacum</italic> and its two progenitors, <italic>N. sylvestris</italic> and <italic>N. tomentosiformis</italic>. After crosses with <italic>N. tabacum</italic>, the two <italic>N. occidentalis</italic> accessions yielded inviable hybrid seedlings whose lethality was characterized by the fading of shoot color, but only the T genome of <italic>N. tabacum</italic> was responsible for hybrid lethality. Genetic analysis indicated that first-mentioned <italic>N. occidentalis</italic> accession carries a single gene causing hybrid lethality by allelic interaction with the S genome.

DOI： 10.1038/s41598-021-96482-6

PubMed

Other URL： https://www.nature.com/articles/s41598-021-96482-6

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Two cultured cell lines (GTH4 and GTH4S) of a Nicotiana interspecific F1 hybrid (N. gossei × N. tabacum) were comparatively analyzed to find genetic factors related to hybrid inviability. Both cell lines proliferated at 37 °C, but after shifting to 26 °C, GTH4 started to die similar to the F1 hybrid seedlings, whereas GTH4S survived. As cell death requires de novo expression of genes and proteins, we compared expressed protein profiles between the two cell lines, and found that NgSGT1, a cochaperone of the chaperone complex (HSP90-SGT1-RAR1), was expressed in GTH4 but not in GTH4S. Agrobacterium-mediated transient expression of NgSGT1, but not NtSGT1, induced cell death in leaves of N. tabacum, suggesting its possible role in hybrid inviability. Cell death in N. tabacum was also induced by transient expression of NgRAR1, but not NtRAR1. In contrast, transient expression of any parental combinations of three components revealed that NgRAR1 promoted cell death, whereas NtRAR1 suppressed it in N. tabacum. A specific inhibitor of HSP90, geldanamycin, inhibited the progression of hypersensitive response-like cell death in GTH4 and leaf tissue after agroinfiltration. The present study suggested that components of the chaperone complex are involved in the inviability of Nicotiana interspecific hybrid.

DOI： 10.1016/j.gene.2021.145443

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

The genus Capsicum is comprised of 5 domesticated and more than 30 wild species. The region of nuclear ribosomal DNA internal transcribed spacers (rDNA-ITS) has widely been used for species identification, but has rarely been used in Capsicum. In this study, the evaluation of genetic diversity and a phylogenetic analysis were conducted using rDNA-ITS of 28 Capsicum accessions, including five domesticated and two wild species. We surveyed six conventional keys of domesticated species and another five traits in Capsicum accessions. Specific morphological characteristics were found in C. annuum, C. baccatum, and C. pubescens. Three subclones of each accession were sequenced, and rDNA-ITS polymorphisms were detected in all accessions excluding C. annuum, suggesting that incomplete concerted evolution occurred in rDNA-ITS of Capsicum. The genetic diversity was evaluated using nucleotide polymorphism and diversity. C. annuum had the lowest genetic diversity of all species in this study. The phylogenetic tree formed a species-specific clade for C. annuum, C. baccatum, and C. pubescens. The C. chinense clade existed in the C. frutescens clade, implying that it was a cultivated variant of C. frutescens. C. chacoense likely belonged to the C. baccatum complex according to its morphologic and genetic features. This study indicated that the rDNA-ITS region can be used for simple identification of domesticated Capsicum species.

DOI： 10.3390/horticulturae6040087

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Hybrid weakness in Capsicum is characterized by the termination of leaf differentiation after the development of several leaves. F1 plants in some crosses between Capsicum annuum and Capsicum chinense show weakness; this phenomenon has not been investigated in detail since first reported. In the present study, we characterized morphologically and physiologically hybrid weakness in Capsicum. F1 plants did not show weaker growth than their parents 20 days after germination (DAG), but at 40 DAG, the hybrid weakness phenotype was evidenced by almost complete arrest of new leaf formation, delayed increase in plant height, and reduced upper internode length. The shoot apical meristem (SAM) of F1 plants exhibited delayed development and an abnormal structure characterized by a flat shape and the presence of fuzzy cell layers on the surface. These abnormal SAMs of F1 plants may lead to dwarfism. Dead cells and accumulation of H2O2 were visually detected in leaves of F1 plants, and cell death was considered to be programmed, as it was accompanied by internucleosomal fragmentation of DNA. The expression of immunity marker genes PR1 and PR2 was upregulated in leaves of F1 plants. These results suggest that a hypersensitive response-like reaction is involved in Capsicum hybrid weakness.

DOI： 10.1270/jsbbs.19137

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Hybrid lethality observed in hybrid seedlings between Nicotiana suaveolens and N. tabacum is characterized by browning, initially of the hypocotyls and eventually of entire seedlings. We investigated the mechanism underlying this browning of tissues. A phenylalanine ammonia-lyase (PAL) gene codes an enzyme involved in a pathway producing phenolic compounds related to the browning of plant tissues. The expression of PAL rapidly increased with the induction of hybrid lethality. Phenolic compounds were observed to be accumulated in whole parts of hybrid seedlings. Treatment of hybrid seedlings with L-2-aminooxy-3-phenylpropionic acid (AOPP), an inhibitor for PAL, suppressed browning and decreased the phenolic content of hybrid seedlings. Although programmed cell death (PCD) was involved in hybrid lethality, AOPP treatment also suppressed cell death and enhanced the growth of hybrid seedlings. These results indicated that PAL is involved in hybrid lethality, and phenolic compounds could be the cause of hybrid lethality-associated tissue browning.

DOI： 10.5511/plantbiotechnology.20.0606a

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Seed abortion and ovary abscission, two types of postzygotic reproductive barriers, are often observed in interspecific and/or interploidy crosses in plants. However, the mechanisms underlying these reproductive barriers remain unclear. Here, we show that the distinct types of seed developmental abnormalities (type I and type II seed abortion) occur in a phased manner as maternal to paternal genome dosage increases and that type II seed abortion is followed by ovary abscission. We revealed that these two types of seed developmental abnormalities are observed during seed development in the interploidy-interspecific crosses of Nicotiana suaveolens and N. tabacum. Moreover, in the cross showing type II seed abortion, several events, such as changes in abscission-related gene expression and lignin deposition, occurred in the ovary abscission zone, eventually leading to ovary abscission. Notably, successive increases in maternal ploidy using ploidy manipulated lines resulted in successive type I and type II seed abortions, and the latter was accompanied by ovary abscission. Conversely, both types of seed abortion and ovary abscission could be overcome with a ploidy manipulation technique that balances parental ploidy levels. We thus concluded that a high maternal genome excess cross may cause severe seed developmental defects and ovary abscission. Based on our findings, we propose a model explaining the abortion phenomena, where an interaction between the promotive and inhibitive effects of the parental genomes determines the developmental destiny of seeds. Significance statement: We demonstrate that a stepwise increase in maternal ploidy results in a stepwise increase in seed abortion severity, leading to ovary abscission in plants. We propose a model explaining the abortion phenomena, where an interaction between the promotive and inhibitive effects of the parental genomes determines the developmental destiny of seeds.

DOI： 10.1002/pld3.257

PubMed

Other URL： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/pld3.257

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Main conclusion: Morphological and genetic markers indicate that in sorghum, the juvenile-to-adult phase transition occurs during the fourth and fifth leaf stages. This timing differs from those reported for other plants. Abstract: The juvenile-to-adult (JA) phase transition is an important event for optimizing vegetative growth and reproductive success in plants. Among the Poaceae crops, which are a vital food source for humans, studies of the JA phase transition have been restricted to rice and maize. We studied the morphological and genetic changes that occur during the early development of sorghum and found that dramatic changes occur in shoot architecture during the early vegetative stages. Changes were observed in leaf size, leaf shape, numbers of trichomes, and size of the shoot apical meristem. In particular, the length/width ratios of the leaf blades in the fifth and upper leaves were completely different from those of the second to fourth leaves. The fifth and upper leaves have trichomes on their adaxial sides, which were absent on the lower leaves. We also analyzed expression of two microRNAs that are known to be molecular markers of the JA phase transition and found that expression of miR156 was highest in the second to fourth leaves and then was gradually down-regulated, whereas miR172 expression followed the opposite pattern. These results suggest that in sorghum, the second and third leaves represent the juvenile phase, the fourth and fifth leaves are in the transition stage, and the sixth and upper leaves are in the adult phase. Thus, the JA phase transition occurs during the fourth and fifth leaf stages. These findings are expected to be useful for understanding the early development of sorghum.

DOI： 10.1007/s00425-019-03251-x

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

<jats:p>Hybrid weakness is a type of reproductive isolation in which F1 hybrids of normal parents exhibit weaker growth characteristics than their parents. F1 hybrid of the Oryza sativa Indian cultivars ‘P.T.B.7′ and ‘A.D.T.14′ exhibits hybrid weakness that is associated with the HWA1 and HWA2 loci. Accordingly, the aim of the present study was to analyze the hybrid weakness phenotype of the ‘P.T.B.7′ × ‘A.D.T.14′ hybrids. The height and tiller number of the F1 hybrid were lower than those of either parent, and F1 hybrid also exhibited leaf yellowing that was not observed in either parent. In addition, the present study demonstrates that SPAD values, an index correlated with chlorophyll content, are effective for evaluating the progression of hybrid weakness that is associated with the HWA1 and HWA2 loci because it accurately reflects degree of leaf yellowing. Both cell death and H2O2, a reactive oxygen species, were detected in the yellowing leaves of the F1 hybrid. Furthermore, disease resistance-related genes were upregulated in the yellowing leaves of the F1 hybrids, whereas photosynthesis-related genes tended to be downregulated. These results suggest that the hybrid weakness associated with the HWA1 and HWA2 loci involves hypersensitive response-like mechanisms.</jats:p>

DOI： 10.3390/plants8110450

PubMed

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Reproductive isolation, including prezygotic and postzygotic barriers, is a mechanism that separates species. Many species in the Nicotiana section Suaveolentes exhibit reproductive isolation in crosses with Nicotiana tabacum. In this study, we investigated whether the chromosome numbers and ploidy levels of eight Nicotiana suaveolens accessions are related to the reproductive isolation after crosses with N. tabacum by flow cytometry and chromosome analyses. Additionally, the internal transcribed spacer (ITS) regions of the eight N. suaveolens accessions were sequenced and compared with the previously reported sequences of 22 Suaveolentes species to elucidate the phylogenetic relationships in the section Suaveolentes. We revealed that four N. suaveolens accessions comprised 64 chromosomes, while the other four accessions carried 32 chromosomes. Depending on the ploidy levels of N. suaveolens, several types of reproductive isolation were observed after crosses with N. tabacum, including decreases in the number of capsules and the germination rates of hybrid seeds, as well as hybrid lethality and abscission of enlarged ovaries at 12–17 days after pollination. A phylogenetic analysis involving ITS sequences divided the eight N. suaveolens accessions into three distinct clades. Based on the results, we confirmed that N. suaveolens accessions vary regarding ploidy levels and reproductive isolation mechanisms in crosses with N. tabacum. These accessions will be very useful for revealing and characterizing the reproductive isolation mechanisms in interspecific crosses and their relationships with ploidy levels.

DOI： 10.1007/s10265-019-01114-w

PubMed

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

DOI： 10.1270/jsbbr.21.W05

J-GLOBAL

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1080/14620316.2018.1439408

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1080/19315260.2014.937022

J-GLOBAL

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Circadian rhythms are observed in many physiological events in plant, and clock genes orchestrate the rhythms of expression of many genes. Precise environmental control of circadian rhythms provides a key technology for enhancing plant growth in artificial environments. In this study, we investigated the basic properties of a circadian rhythm for establishment of its control engineering in lettuce (<i>Lactuca sativa</i> L.). Bioluminescence of transgenic lettuce carrying an <i>AtCCA1::LUC</i> construct as a reporter of circadian gene expression was measured in young lettuce seedlings. We observed three basic properties; free-running circadian rhythms under constant conditions without day-night cycles, entrainment to red and blue light cycles with 12 h light-12 h dark period, and temperature compensation of a free-running period in three lettuce cultivars (Cisco, Cos, Greenwave). In addition, a light-quality dependence of the free-running period and sensitivity to blue-light cycles with small amplitude (20% of variance in average light intensity) and non-24 h period were also observed. The results in this study indicated that it is possible to control lettuce circadian rhythms by non-24 h period light cycles in LED illumination. It will play an important role in the research of control engineering for the circadian clock of lettuce in closed plant factories with artificial lighting.

DOI： 10.2525/ecb.52.21

CiNii Article

Other URL： https://jlc.jst.go.jp/DN/JALC/10032836331?from=CiNii

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Eggplant (<I>Solanum melongena</I>) seedlings cultured <I>in vitro</I> were excised at the center of the hypocotyl to generate decapitated seedlings with intact roots. This modification of the complete decapitation method (CDM) developed <I>in vivo</I> by Harada et al. (2005) allowed <I>in vitro</I> culture (CDM <I>in vitro</I>; CDM<I>i</I>). As controls, rootless hypocotyl segment explants (approximately 1 cm) and cotyledon explants were cultured on media supplemented with 4.4 μM 6-benzyladenin (BA) and 0.2 μM thidiazuron (TDZ), respectively. Cotyledon explants had formed calli 2 weeks after excision but did not develop adventitious buds, despite the use of optimal conditions reported previously for a different eggplant cultivar. Calli formed at the cut ends of hypocotyls 1 week after excision in both CDM<I>i</I> and hypocotyl cultures, and adventitious buds regenerated 1 week earlier in CDM<I>i</I>. Six weeks after excision, CDM<I>i</I> yielded 11.4 adventitious buds per explant, but only 4.1 formed in hypocotyl culture. Moreover, shoots longer than 1 cm developed 2 weeks earlier in CDM<I>i</I> than in hypocotyl culture. The number of shoots per explant was 8.1 in CDM<I>i</I>, but only 2.4 in hypocotyl culture 6 weeks after cutting. All shoots that developed were rooted on MS medium in CDM<I>i</I>, but only 71% of shoots formed roots in hypocotyl culture. These results indicate that intact roots are important for explant shoot regeneration and development, and CDM<I>i</I> is a simple and efficient method for obtaining multiple shoots without the need to determine optimal concentrations of plant growth regulators and overcome inhibition of rooting in the obtained shoots.

DOI： 10.3117/plantroot.7.5

CiNii Article

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.5897/AJB12.1812

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.21273/HORTSCI.48.3.352

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

<jats:p><jats:italic>Ardisia crenata</jats:italic> is an evergreen shrub with attractive bright red berries. Although this species is usually propagated by seed, the seeds take a long time to germinate with conventional sowing methods. We investigated the germination capacity of seeds and embryos collected in different months and the effects of seed storage conditions, germination temperature, water permeability of the seed coat, and the endosperm on seed germination. Seeds and embryos collected in late September or later showed good germination rates. Seeds germinated more rapidly after longer periods of storage at low temperature (approximately 5°C), and those stored in dry conditions showed lower emergence frequency than those stored in wet conditions. Seeds germinated at 15–30°C, but not at 5–10°C. Removal of the seed coat enhanced water uptake and seed germination. Seeds with various proportions of the removed seed coat were sown on a medium supplemented with sucrose. The germination frequency increased as the size of the remaining endosperm decreased. However, the opposite results were obtained when seeds were sown on a medium without sucrose. We concluded that the optimal temperature of 25°C is the most critical factor for seed germination in <jats:italic>A. crenata</jats:italic>.</jats:p>

DOI： 10.1155/2012/679765

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

An <i>in vivo</i> method to promote adventitious bud formation in leaf apex explants of <i>Begonia</i>×<i>tuberhybrida</i> was developed based on exogenous treatment with BA, IAA and NAA. Endogenous IAA concentrations of the leaf blade were highest in the apical portion, followed by the middle and basal portions. Treatment with 0.5 mg L⁻¹ BA increased the percentage of adventitious bud formation to 15% from 0% at 0 mg L⁻¹ BA, but treatment with BA at concentrations higher than 0.5 mg L⁻¹ had no additional promotive effect. Adventitious bud formation was increased to 53% by treatment with 0.1 mg L⁻¹ IAA and 0.5 mg L⁻¹ BA, and inhibited by 1.0 and 5.0 mg L⁻¹ IAA. The optimal duration of treatment with 0.1 mg L⁻¹ IAA was 2–8 days after embedding. No explants formed adventitious buds when treated with fresh 0.1 mg L⁻¹ IAA at 2-day intervals until 16 days after initial embedding. Similar responses were observed in explants treated with 0.1 mg L⁻¹ NAA. These results suggested that temporary IAA treatment at 0.1 mg L⁻¹ during the initial period of embedding is an efficient <i>in vivo</i> method to induce adventitious bud formation in leaf apex explants in <i>B.×tuberhybrida</i>.

DOI： 10.2525/ecb.50.319

CiNii Article

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1007/s10681-011-0570-3

CiNii Article

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1371/journal.pone.0037822

PubMed

CiNii Article

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1371/journal.pone.0036204

PubMed

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Adventitious shoots can be regenerated from the cut surface of the primary shoot and lateral branches in decapitated plants in vivo. This inherent regenerative ability of plants is useful for mass propagation. In the present study, we conducted histological observations of shoot regeneration and applied auxin and cytokinin to decapitated seedlings in four tomato cultivars. The cultivars produced different numbers of adventitious shoots after decapitation; 'Petit' produced the largest number of adventitious shoots (78.5 +/- 10.2) and 'Momotaro' produced the fewest (12.1 +/- 3.3). Histological observation of 'Petit' revealed that adventitious shoots regenerated from calli formed at the cut surface of stems. Adventitious shoot formation was inhibited by the presence of lateral branches. Shoot regeneration was prevented by application of 1-naphthaleneacetic acid to 'Petit'. Application of 6-benzyladenine promoted shoot regeneration in 'Momotaro'. These results suggest auxin synthesized de novo from the lateral branches inhibited shoot regeneration after decapitation and endogenous cytokinin might stimulate shoot regeneration. Chemical names: 1-naphthaleneacetic acid (NAA); 6-benzyladenine (BA)

DOI： 10.21273/HORTSCI.46.12.1661

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Hybrid weakness phenomena in rice reportedly have two causes: those of HWC1 and HWC2 genes and those of HWA1 and HWA2 genes. No detailed study of the latter has been reported. For this study, we first produced crosses among cultivars carrying the weakness-causing allele on the HWA1 and HWA2 loci to confirm the phenotype of the hybrid weakness and the genotypes of the cultivars on the two loci, as reported earlier. We then confirmed that these cultivars belong to Indica. Subsequent linkage analysis of HWA1 and HWA2 genes conducted using DNA markers revealed that both genes are located in the 1,637-kb region, surrounded by the same DNA markers on the long arm of chromosome 11. The possibility of allelic interaction inducing hybrid weakness is discussed.

DOI： 10.1007/s12284-011-9062-2

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

P&gt;Use of resistance genes would be the most effective way to address Fusarium wilt caused by Fusarium oxysporum f.sp. melonis in melon. In this study, based on the BAC 31O16 sequence which contains the cluster of melon resistance gene homologue, we developed four new DNA markers linked to Fom-1, a dominant resistance gene against F. oxysporum f.sp. melonis races 0 and 2. Linkage analysis using 125 F-2 plants derived from the cross between P11 (fom-1fom-1) and MR-1 (Fom-1Fom-1) indicated that Fom-1 was located between CAPS markers C-MRGH12 and 62-CAPS at a distance of 0.4 and 1.2 cM, respectively. Map position of Fom-1 was confirmed using another mapping population consisting of 104 recombinant inbred lines derived from the cross P11 x MR-1. The analysis of 43 fixed lines and 27 commercial F-1 hybrids showed that the developed DNA markers linked to Fom-1 correctly predicted the genotype in relation to the variety, suggesting that the region around the Fom-1 locus is very polymorphic or there is no linkage disequilibrium between the locus and the marker loci.

DOI： 10.1111/j.1439-0523.2010.01800.x

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

Inviability of hybrids, often referred to as hybrid lethality, is a type of reproductive isolation. Hybrid lethality is observed in some plant species, including <i>Nicotiana</i> species, and can be an obstacle when desirable genes are to be introduced into cultivated species by wide hybridization. Wild species in <i>Nicotiana</i> section <i>Suaveolentes</i> (which consists of species restricted to Australasia and Africa) yield inviable hybrids after crosses with the cultivated species <i>N. tabacum</i>. Genetic studies have revealed that hybrid lethality in the cross <i>N. tabacum</i>×<i>N. debneyi</i> is caused by the interaction between gene(s) on the Q chromosome of <i>N. tabacum</i> and a single dominant gene in <i>N. debneyi</i>. Furthermore, programmed cell death with apoptotic features is involved in hybrid lethality. Some factors related to hybrid lethality have been elucidated in the cross <i>N. suaveolens</i>×<i>N. tabacum</i>.

DOI： 10.18964/jcr.56.0_9

CiNii Article

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.2503/jjshs1.79.367

CiNii Article

J-GLOBAL

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1093/aob/mcq114

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1007/s10681-009-9881-z

Publishing type：Research paper (bulletin of university, research institution)   International / domestic magazine：Domestic journal  

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1007/s00425-007-0522-2

PubMed

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1007/s00122-006-0219-0

PubMed

CiNii Article

Authorship：Lead author,　Corresponding author   Publishing type：Doctoral thesis  

指導教員：丸橋亘；指導教員・主査：松田智明；第1副指導教員・副査：久保山勉；第2副指導教員・副査：金子幸雄；副査：松澤康男、平田豊

Authorship：Lead author   Publishing type：Research paper (international conference proceedings)  

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

DOI： 10.1093/pcp/pch204

PubMed

CiNii Article

Authorship：Lead author   Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Hybrid seedlings from the cross <i>Nicotiana tabacum</i> ×<i>N. suaveolens</i>, obtained by test-tube pollination and ovule culture, expressed lethality at 28°C. Characteristic lethal symptoms in these hybrid seedlings consisted of browning of hypocotyls and roots. One hundred and seventeen hybrid seedlings were eventually obtained by the use of test-tube pollination and ovule culture. Hybrid seedlings maintained at 36°C did not express any lethal symptoms. Hybrid seedlings used for further experiments were transferred to 36°C immediately after germination at 28°C. When hybrid seedlings cultured at 36°C were transferred to 28°C, their growth stopped and lethal symptoms were expressed. During the progressive expression of lethality, apoptotic features such as chromatin condensation, nuclear fragmentation and DNA fragmentation were detected. On the other hand, there was no sign of apoptotic cell death in the hybrid seedlings at 36°C. Based on the observation that the same lethal symptoms and the same apoptotic features were observed in the reciprocal cross, <i>N. suaveolens</i> ×<i>N. tabacum</i>, we suggest that not only the underlying causes of hybrid lethality but also the underlying causes of apoptotic cell death are due to the interaction of coexisting heterogeneous genomes, rather than to the effect of cytoplasmic genes. Furthermore, the progression of apoptotic cell death in the cross <i>N. tabacum</i> × <i>N. suaveolens</i> began in stems and roots, followed by leaves.<br>

DOI： 10.1270/jsbbs.54.59

CiNii Article

Publishing type：Research paper (international conference proceedings)  

Authorship：Lead author,　Corresponding author   Publishing type：Master’s thesis  

指導教員・主査：丸橋亘；副査：久保山勉、久留主泰朗

Authorship：Lead author,　Corresponding author   Publishing type：Thesis (other)  

指導教員：丹羽勝

Presentation type：Oral presentation (general)  

Venue：東京大学  

Presentation type：Oral presentation (general)  

Venue：静岡大学  

Presentation type：Oral presentation (general)  

Venue：静岡大学  

Presentation type：Oral presentation (general)  

Venue：静岡大学  

Presentation type：Poster presentation  

Venue：摂南大学（オンライン開催）  

Presentation type：Poster presentation  

Venue：オンライン  

Presentation type：Poster presentation  

Venue：オンライン  

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Presentation type：Poster presentation  

Presentation type：Oral presentation (general)  

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Presentation type：Symposium, workshop panel (public)  

Presentation type：Symposium, workshop panel (public)  

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Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)  

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Presentation type：Poster presentation  

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Presentation type：Poster presentation  

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Presentation type：Poster presentation  

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Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)