Although the molecular basis of flowering time control is well dissected in the long day (LD) plant Arabidopsis, it is still largely unknown in the short day (SD) plant rice. Rice flowering time (heading date) i...Although the molecular basis of flowering time control is well dissected in the long day (LD) plant Arabidopsis, it is still largely unknown in the short day (SD) plant rice. Rice flowering time (heading date) is an important agronomic trait for season adaption and grain yield, which is affected by both genetic and environmental factors. During the last decade, as the nature of florigen was identified, notable progress has been made on exploration how florigen gene ,expression is genetically controlled. In Arabidopsis expression of certain key flowering integrators such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT) are also epige- netically regulated by various chromatin modifications, however, very little is known in rice on this aspect until very recently. This review summarized the advances of both genetic networks and chromatin modifications in rice flowering time control, attempting to give a complete view of the genetic and epigenetic architecture in complex network of rice flowering pathways.展开更多
Meiosis is the crucial process by which sexually propagating eukaryotes give rise to haploid gametes from diploid cells. Several key processes, like homologous chromosomes pairing, synapsis, recombination, and segrega...Meiosis is the crucial process by which sexually propagating eukaryotes give rise to haploid gametes from diploid cells. Several key processes, like homologous chromosomes pairing, synapsis, recombination, and segregation, sequentially take place in meiosis. Although these widely conserved events are under both genetic and epigenetic control, the accurate details of molecular mechanisms are continuing to investigate. Rice is a good model organism for exploring the molecular mechanisms of meiosis in higher plants. So far, 28 rice meiotic genes have been characterized. In this review, we give an overview of the discovery of rice meiotic genes in the last ten years, with a particular focus on their functions in meiosis.展开更多
Gibberellin (GA) 2-oxidase plays a key role in the GA catabolic pathway through 2β-hydroxylation.In the present study,we isolated a CaMV 35S-enhancer activation tagged mutant,H032.This mutant exhibited a dominant d...Gibberellin (GA) 2-oxidase plays a key role in the GA catabolic pathway through 2β-hydroxylation.In the present study,we isolated a CaMV 35S-enhancer activation tagged mutant,H032.This mutant exhibited a dominant dwarf and GA-deficient phenotype,with a final stature that was less than half of its wild-type counterpart.The endogenous bioactive GAs are markedly decreased in the H032 mutant,and application of bioactive GAs (GA3 or GA4) can reverse the dwarf phenotype.The integrated T-DNA was detected 12.8 kb upstream of the OsGA2ox6 in the H032 genome by TAIL-PCR.An increased level of OsGA2ox6 mRNA was detected at a high level in the H032 mutant,which might be due to the enhancer role of the CaMV 35S promoter.RNAi and ectopic expression analysis of OsGA2ox6 indicated that the dwarf trait and the decreased levels of bioactive GAs in the H032 mutant were a result of the up-regulation of the OsGA2ox6 gene.BLASTP analysis revealed that OsGA2ox6 belongs to the class III of GA 2-oxidases,which is a novel type of GA2ox that uses C20-GAs (GA12 and/or GA53) as the substrates.Interestingly,we found that a GA biosynthesis inhibitor,paclobutrazol,positively regulated the OsGA2ox6 gene.Unlike the over-expression of OsGA2ox1,which led to a high rate of seed abortion,the H032 mutant retained normal flowering and seed production.These results indicate that OsGA2ox6 mainly affects plant stature,and the dominant dwarf trait of the H032 mutant can be used as an efficient dwarf resource in rice breeding.展开更多
Apomixis is an asexual reproduction way of plants that can produce clonal offspring through seeds.In this study,we introduced apomixis into rice(Oryza sativa)by mutating OsSPO11-1,OsREC8,OsOSD1,and OsMATL through a CR...Apomixis is an asexual reproduction way of plants that can produce clonal offspring through seeds.In this study,we introduced apomixis into rice(Oryza sativa)by mutating OsSPO11-1,OsREC8,OsOSD1,and OsMATL through a CRISPR/Cas9 system.The quadruple mutant showed a transformation from meiosis to mitosis and produced clonal diploid gametes.With mutated Osmatl,which gives rise to haploid induction in plants,the quadruple mutant is expected to be able to be produced apomictic diploid offspring.We named this quadruple mutant as AOP(Apomictic Offspring Producer)for its ability to produce apomictic offspring.展开更多
MSH5, a meiosis-specific member of the MutS-homolog family, is required for normal level of recombination in budding yeast, mice, Caenorhabditis elegans, and Arabidopsis. Here, we report the identification and charact...MSH5, a meiosis-specific member of the MutS-homolog family, is required for normal level of recombination in budding yeast, mice, Caenorhabditis elegans, and Arabidopsis. Here, we report the identification and characterization of its rice homolog, OsMSH5, and demonstrate its function in rice meiosis. Five independent Osmsh5 mutants exhibited normal vegetative growth and severe sterility. The synaptonemal complex is well installed in Osmsh5, while the chiasma frequency is greatly reduced to approximately 10% of that observed in the wild-type, leading to the homologous non- disjunction and complete sterile phenotype. OsMSH5 is predominantly expressed in panicles. Immunofluorescence studies indicate that OsMSH5 chromosomal localization is limited to the early meiotic prophase I. OsMSH5 can be loaded onto meiotic chromosomes in Oszip4, Osmer3, and hellO. However, those ZMM proteins cannot be localized normally in the absence of OsMSH5. Furthermore, the residual chiasmata were shown to be the least frequent among the zmm mutants, including Osmer3, Oszip4, hellO, and Osmsh5. Taken together, we propose that OsMSH5 functions upstream of OsZIP4, OsMER3, and HEIl0 in class I crossover formation.展开更多
To develop reliable techniques for chromosome identification is critical for cytogenetic research, especially for genomes with a large number and smaller-sized chromosomes. An efficient approach using bacterial artifi...To develop reliable techniques for chromosome identification is critical for cytogenetic research, especially for genomes with a large number and smaller-sized chromosomes. An efficient approach using bacterial artificial chromosome (BAC) clones as molecular cytological markers has been developed for many organisms. Herein, we present a set of chromosomal arm-specific molecular cytological markers derived from the gene-enriched regions of the sequenced rice genome. All these markers are able to generate very strong signals on the pachytene chromosomes of Oryza sativa L. (AA genome) when used as fluorescence in situ hybridization (FISH) probes. We further probed those markers to the pachytene chromosomes of O. punctata (BB genome) and O. officinalis (CC genome) and also got very strong signals on the relevant pachytene chromosomes. The signal position of each marker on the related chromosomes from the three different rice genomes was pretty much stable, which enabled us to identify different chromosomes among various rice genomes. We also constructed the karyotype for both O. punctata and O. officinalis with the BB and CC genomes, respectively, by analysis of 10 pachytene cells anchored by these chromosomal arm-specific markers.展开更多
Dear Editor,Meiotic recombination is initiated by the generation of DNA double-strand breaks (DSBs), which are catalyzed by the Spo11 protein (de Massy, 2013). Two key findings point to the role of Spo11 as the in...Dear Editor,Meiotic recombination is initiated by the generation of DNA double-strand breaks (DSBs), which are catalyzed by the Spo11 protein (de Massy, 2013). Two key findings point to the role of Spo11 as the initiator of DSB formation in budding yeast: (1) Spo11 is linked to the 5' termini of the broken DNA molecules in rad50s mutants, whose meiosis has been blocked at the stage of the cleavaqe reaction ('Keenev et al., 1997).展开更多
Combined approaches with genetics, biochemistry, and proteomics studies have greatly advanced our understanding of brassinosteroid (BR) signaling in Arabidopsis. However, in rice, a model plant of monocot and as wel...Combined approaches with genetics, biochemistry, and proteomics studies have greatly advanced our understanding of brassinosteroid (BR) signaling in Arabidopsis. However, in rice, a model plant of monocot and as well an important crop plant, BR signaling is not as well characterized as in Arabidopsis. Recent studies by forward and reverse genetics have identified a number of either conserved or specific components of rice BR signaling pathway, bringing new ideas into BR signaling regulation mechanisms. Genetic manipulation of BR level or BR sensitivity to improve rice yield has established the great significance of BR research achievements.展开更多
Cuticular wax forms a hydrophobic barrier on aerial plant organs; it plays an important role in protecting a plant from damage caused by many forms of environmental stress. In the present study, we characterized a ric...Cuticular wax forms a hydrophobic barrier on aerial plant organs; it plays an important role in protecting a plant from damage caused by many forms of environmental stress. In the present study, we characterized a rice leaf wax-deficient mutant osgll-1 derived from a spontaneous mutation, which exhibited a wax-deficient and highly hydro- philic leaf phenotype. We cloned the OsGLI-1 gene by the map-based cloning method and performed a complementation test to confirm the function of the candidate gene. Molecular studies revealed that OsGLI-1 was a member of the OsGL1 family, and contained regions that were homologous to some regions in sterol desaturases and short-chain dehydro- genases/reductases. Compared to the wild-type, the osgll-1 mutant showed decreased cuticular wax deposition, thinner cuticular membrane, decreased chlorophyll leaching, increased rate of water loss, and enhanced sensitivity to drought. OsGL 1-1 is expressed ubiquitously in rice. The transient expression of OsGLl-l-green fluorescent protein fusion protein indicated that OsGLI-1 is localized in the cytoplasm, plasma membrane, and nucleus.展开更多
On November 18, 2018, the Future Science Prize Awarding Ceremony was held in Beijing. In the area of life science, Professors Jiayang Li, Longping Yuan, and Qifa Zhang shared the prize for their pioneering contributio...On November 18, 2018, the Future Science Prize Awarding Ceremony was held in Beijing. In the area of life science, Professors Jiayang Li, Longping Yuan, and Qifa Zhang shared the prize for their pioneering contributions in producing high-yield, superior-quality rice through systematic study of molecular mechanisms associated with speci?c rice features and application of novel approaches in rice breeding. The Future Science Prize is also touted as ‘‘China’s Nobel Prize", fully af?rming their achievements in rice basic research and breeding.展开更多
基金Acknowledgments We are grateful to Dr Xinnian Dong (Duke University, Durham, NC, USA) for critical reading of the manuscript and valuable suggestions. We thank Dr Jianmin Zhou (National Institute of Biological Sciences, Beijing, China) for providing the fungus strain Botrytis cinerea, Dr Salome Prat (Institut de Biologia Molecular de Barcelona, Barcelona, Spain) for providing homozygous atmyc2-2 (T-DNA insertion line SALK_083483) seeds and Dr Daoxin Xie (Tsinghua University, Beijing, China) for providing the coil-I seeds. This work was supported by grants from The National Natural Science Foundation of China (30530440), The Ministry of Science and Technology of China (2006CB 102004, 2006AA10A 116), and The Chinese Academy of Sciences (KSCX2-YW-N-045).
基金This study was financially supported by the National Natural Science Foundation of China (Grant Nos. 31371602 and 91335107) and Specialized Research Fund for the Doctoral Program of Higher Education (20125103120008).
文摘Although the molecular basis of flowering time control is well dissected in the long day (LD) plant Arabidopsis, it is still largely unknown in the short day (SD) plant rice. Rice flowering time (heading date) is an important agronomic trait for season adaption and grain yield, which is affected by both genetic and environmental factors. During the last decade, as the nature of florigen was identified, notable progress has been made on exploration how florigen gene ,expression is genetically controlled. In Arabidopsis expression of certain key flowering integrators such as FLOWERING LOCUS C (FLC) and FLOWERING LOCUS T (FT) are also epige- netically regulated by various chromatin modifications, however, very little is known in rice on this aspect until very recently. This review summarized the advances of both genetic networks and chromatin modifications in rice flowering time control, attempting to give a complete view of the genetic and epigenetic architecture in complex network of rice flowering pathways.
基金supported by grants from the National Natural Science Foundation of China(Nos.31360260, 31230038 and U1302261)
文摘Meiosis is the crucial process by which sexually propagating eukaryotes give rise to haploid gametes from diploid cells. Several key processes, like homologous chromosomes pairing, synapsis, recombination, and segregation, sequentially take place in meiosis. Although these widely conserved events are under both genetic and epigenetic control, the accurate details of molecular mechanisms are continuing to investigate. Rice is a good model organism for exploring the molecular mechanisms of meiosis in higher plants. So far, 28 rice meiotic genes have been characterized. In this review, we give an overview of the discovery of rice meiotic genes in the last ten years, with a particular focus on their functions in meiosis.
基金supported by grants from the Ministry of Sciences and Technology of China (No. 2005CB120805 and 2006AA10A101)the National Natural Science Foundation of China (No. 30621001 and 30871512)
文摘Gibberellin (GA) 2-oxidase plays a key role in the GA catabolic pathway through 2β-hydroxylation.In the present study,we isolated a CaMV 35S-enhancer activation tagged mutant,H032.This mutant exhibited a dominant dwarf and GA-deficient phenotype,with a final stature that was less than half of its wild-type counterpart.The endogenous bioactive GAs are markedly decreased in the H032 mutant,and application of bioactive GAs (GA3 or GA4) can reverse the dwarf phenotype.The integrated T-DNA was detected 12.8 kb upstream of the OsGA2ox6 in the H032 genome by TAIL-PCR.An increased level of OsGA2ox6 mRNA was detected at a high level in the H032 mutant,which might be due to the enhancer role of the CaMV 35S promoter.RNAi and ectopic expression analysis of OsGA2ox6 indicated that the dwarf trait and the decreased levels of bioactive GAs in the H032 mutant were a result of the up-regulation of the OsGA2ox6 gene.BLASTP analysis revealed that OsGA2ox6 belongs to the class III of GA 2-oxidases,which is a novel type of GA2ox that uses C20-GAs (GA12 and/or GA53) as the substrates.Interestingly,we found that a GA biosynthesis inhibitor,paclobutrazol,positively regulated the OsGA2ox6 gene.Unlike the over-expression of OsGA2ox1,which led to a high rate of seed abortion,the H032 mutant retained normal flowering and seed production.These results indicate that OsGA2ox6 mainly affects plant stature,and the dominant dwarf trait of the H032 mutant can be used as an efficient dwarf resource in rice breeding.
基金supported by grants from the Ministry of Sciences and Technology of China (2016YFD0101801)the National Natural Science Foundation of China (31771363)
文摘Apomixis is an asexual reproduction way of plants that can produce clonal offspring through seeds.In this study,we introduced apomixis into rice(Oryza sativa)by mutating OsSPO11-1,OsREC8,OsOSD1,and OsMATL through a CRISPR/Cas9 system.The quadruple mutant showed a transformation from meiosis to mitosis and produced clonal diploid gametes.With mutated Osmatl,which gives rise to haploid induction in plants,the quadruple mutant is expected to be able to be produced apomictic diploid offspring.We named this quadruple mutant as AOP(Apomictic Offspring Producer)for its ability to produce apomictic offspring.
基金This work was supported by grants from the Ministry of Sciences and Technology of China (2011CB944602 and 2012AA10A301)the State Key Laboratory of Plant Genomics of China (2012A0527)and the National Natural Science Foundation of China (31160223 and 31230038). No conflict of interest declared.
文摘MSH5, a meiosis-specific member of the MutS-homolog family, is required for normal level of recombination in budding yeast, mice, Caenorhabditis elegans, and Arabidopsis. Here, we report the identification and characterization of its rice homolog, OsMSH5, and demonstrate its function in rice meiosis. Five independent Osmsh5 mutants exhibited normal vegetative growth and severe sterility. The synaptonemal complex is well installed in Osmsh5, while the chiasma frequency is greatly reduced to approximately 10% of that observed in the wild-type, leading to the homologous non- disjunction and complete sterile phenotype. OsMSH5 is predominantly expressed in panicles. Immunofluorescence studies indicate that OsMSH5 chromosomal localization is limited to the early meiotic prophase I. OsMSH5 can be loaded onto meiotic chromosomes in Oszip4, Osmer3, and hellO. However, those ZMM proteins cannot be localized normally in the absence of OsMSH5. Furthermore, the residual chiasmata were shown to be the least frequent among the zmm mutants, including Osmer3, Oszip4, hellO, and Osmsh5. Taken together, we propose that OsMSH5 functions upstream of OsZIP4, OsMER3, and HEIl0 in class I crossover formation.
基金Supported by the National Natural Science Foundation of China (30325008, 30428019 and 30530070). Publication of this paper is supported by the National Natural Science Foundation of China (30624808).
文摘To develop reliable techniques for chromosome identification is critical for cytogenetic research, especially for genomes with a large number and smaller-sized chromosomes. An efficient approach using bacterial artificial chromosome (BAC) clones as molecular cytological markers has been developed for many organisms. Herein, we present a set of chromosomal arm-specific molecular cytological markers derived from the gene-enriched regions of the sequenced rice genome. All these markers are able to generate very strong signals on the pachytene chromosomes of Oryza sativa L. (AA genome) when used as fluorescence in situ hybridization (FISH) probes. We further probed those markers to the pachytene chromosomes of O. punctata (BB genome) and O. officinalis (CC genome) and also got very strong signals on the relevant pachytene chromosomes. The signal position of each marker on the related chromosomes from the three different rice genomes was pretty much stable, which enabled us to identify different chromosomes among various rice genomes. We also constructed the karyotype for both O. punctata and O. officinalis with the BB and CC genomes, respectively, by analysis of 10 pachytene cells anchored by these chromosomal arm-specific markers.
文摘Dear Editor,Meiotic recombination is initiated by the generation of DNA double-strand breaks (DSBs), which are catalyzed by the Spo11 protein (de Massy, 2013). Two key findings point to the role of Spo11 as the initiator of DSB formation in budding yeast: (1) Spo11 is linked to the 5' termini of the broken DNA molecules in rad50s mutants, whose meiosis has been blocked at the stage of the cleavaqe reaction ('Keenev et al., 1997).
基金supported by grants from the National Natural Science Foundation of China(Nos.31170715, 30825029,and 30621001)the Ministry of Agriculture of China(No.2011ZX08009-003)
文摘Combined approaches with genetics, biochemistry, and proteomics studies have greatly advanced our understanding of brassinosteroid (BR) signaling in Arabidopsis. However, in rice, a model plant of monocot and as well an important crop plant, BR signaling is not as well characterized as in Arabidopsis. Recent studies by forward and reverse genetics have identified a number of either conserved or specific components of rice BR signaling pathway, bringing new ideas into BR signaling regulation mechanisms. Genetic manipulation of BR level or BR sensitivity to improve rice yield has established the great significance of BR research achievements.
文摘Cuticular wax forms a hydrophobic barrier on aerial plant organs; it plays an important role in protecting a plant from damage caused by many forms of environmental stress. In the present study, we characterized a rice leaf wax-deficient mutant osgll-1 derived from a spontaneous mutation, which exhibited a wax-deficient and highly hydro- philic leaf phenotype. We cloned the OsGLI-1 gene by the map-based cloning method and performed a complementation test to confirm the function of the candidate gene. Molecular studies revealed that OsGLI-1 was a member of the OsGL1 family, and contained regions that were homologous to some regions in sterol desaturases and short-chain dehydro- genases/reductases. Compared to the wild-type, the osgll-1 mutant showed decreased cuticular wax deposition, thinner cuticular membrane, decreased chlorophyll leaching, increased rate of water loss, and enhanced sensitivity to drought. OsGL 1-1 is expressed ubiquitously in rice. The transient expression of OsGLl-l-green fluorescent protein fusion protein indicated that OsGLI-1 is localized in the cytoplasm, plasma membrane, and nucleus.
文摘On November 18, 2018, the Future Science Prize Awarding Ceremony was held in Beijing. In the area of life science, Professors Jiayang Li, Longping Yuan, and Qifa Zhang shared the prize for their pioneering contributions in producing high-yield, superior-quality rice through systematic study of molecular mechanisms associated with speci?c rice features and application of novel approaches in rice breeding. The Future Science Prize is also touted as ‘‘China’s Nobel Prize", fully af?rming their achievements in rice basic research and breeding.