Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1...Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1BS was reported in the last century,but the underlying gene and its molecular basis remained elusive.Here,we identified TraesTSP1B01G005700(G57)encoding an R2R3-MYB transcription factor(TF)as the candidate Rg-B1 gene controlling red glume color by a combination of genome-wide association study(GWAS),bulked segregant RNA-sequencing(BSR-Seq),map-based cloning,and RNAseq.The Rg-B1 locus had zero to five duplicate copies only one of which had high transcriptional activity.Genetic evidence suggested that promoter sequence variation in G57 in the glume leads to high expression of G57,resulting in the red glume phenotype.G57 could bind to the promoters of anthocyanin synthesis genes TaCHS,TaF3'H,and TaUFGT,activating their expression and contributing to anthocyanin accumulation in wheat glume.G57 also played a pivotal role in up-regulating expression of genes TaDREB1C and TaFLO2 associated with increased grain weight,thereby causing increased grain weight.Our research offers a better understanding of the molecular basis of red glume in bread wheat.展开更多
The glume is an organ of the maize spikelet and plays important roles in anther and kernel development.Vestigial glume1(Vg1)is a classic mutant associated with ligule and glume development.Here we report the phenotypi...The glume is an organ of the maize spikelet and plays important roles in anther and kernel development.Vestigial glume1(Vg1)is a classic mutant associated with ligule and glume development.Here we report the phenotypic characterization,fine mapping,and candidate gene analysis of the Vg1 mutant.Vg1 is a semi-dominant and pleiotropic gene,and also affects plant height,ear height,and tassel length.Vg1 ligule degeneration begins at the first leaf,and the Vg1 tassel and ear can be distinguished from those of wild-type plants when their lengths reach respectively 55 mm and 51 mm.Using a BC3 mapping population of 11,445 plants,we delimited the Vg1 functional site to an interval of 7.4 kb,flanked by the markers InDelLM and CRM6.A putative cyclopropane fatty-acid synthase gene(ZmCPA-FAS1)was hypothesized to underlie the mutant phenotype.We detected a Helitron insertion in the sixth intron of ZmCPAFAS1.Its presence caused abnormal alternative splicing of ZmCPA-FAS1 that conferred new characteristics on the Vg1 mutant.These findings are a basis for further discovery of the molecularmechanism underlying glume development and a potential guide formaize breeding of small-glume varieties,especially sweet corn breeding.展开更多
Although there is evident homology among reproductive organs when comparing Poaceae （grass） and eudicots, the identity of grass specific organs, such as lodicules, palea, lemma, and glumes has been the subject of a ...Although there is evident homology among reproductive organs when comparing Poaceae （grass） and eudicots, the identity of grass specific organs, such as lodicules, palea, lemma, and glumes has been the subject of a vast and largely inconclusive discussion. Here we provide some direct evidence to support the idea that the empty glumes of rice （Oryza sativa） are counterparts of lemmas. We show that the development of empty glumes is regulated by ELE （elongated empty glume）, which belongs to a plant specific novel gene family. Mutations at the ELE locus cause elongated empty glumes, which mimic the lemmas and have the epidermal morphology of lemmas with four or five vascular bundles. As a nuclear-localized gene, ELE is specifically expressed at the empty glumes of immature spikelets, and its ectopic expression causes many floral development defects, including lemma-like palea, extra palea-like structures, elongated lodicules, extra stamens and stigmas. Our result suggests that empty glumes are lemmas of the sterile florets located at the lateral side of the rice spikelet, and ELE acts as a regulator restraining its growth to maintain its small size in wild-type plants.展开更多
The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and scre...The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and screening. The fosmid library of Vg1 consisted of574,000 clones with an average insert size of 36.4 kb, representing 7.9-fold coverage of the maize genome. Fosmid stability assays indicated that clones were stable during propagation in the fosmid system. Using Vg1 candidate gene-specific primers, a positive clone was successfully identified. This discovery will pave the way for identifying the function of Vg1 in maize development.展开更多
A rice mutant with Yaponica 9522 cultivar background Oryza sativa extraordinary glume 1 （Oseg 1） was identified from the M2 mutant pool mutagenized by ^60Co γ-ray. Compared with wild type plants, Oseg 1 developed l...A rice mutant with Yaponica 9522 cultivar background Oryza sativa extraordinary glume 1 （Oseg 1） was identified from the M2 mutant pool mutagenized by ^60Co γ-ray. Compared with wild type plants, Oseg 1 developed longer empty glumes and rudimentary glumes. In some Oseg 1 mutants, the number of stamens of flowers was reduced and leaf-like lodicules occurred, and excessive lemma/palea-like organ could be observed in some mutant spikelets. This indicated that OsEG1 could regulate the development of rudimentary glumes, empty glumes, lemma/palea, lodicules, and stamens. Genetic analysis indicated that Oseg 1 came from a single recessive genetic locus. To clone OsEG1 gene, F2 population was constructed by a cross between Oseg 1 （Japonica） and Guangluai4 （Indica）. Using map-based cloning approach, OsEG1 was mapped on chromosome 4, between INDEL marker OS407 and WHM0466 with genetic distance of 2.0 cm and 1.0 cm, respectively. These results are useful for further cloning and functional analysis of the OsEG1 gene.展开更多
A multi-glume （mg） mutant was obtained by screening the T-DNA inserted mutant pool. Anatomical observation revealed that the florets of the mutant showed elongated leafy paleas/lemmas and palea/lemma-like structures...A multi-glume （mg） mutant was obtained by screening the T-DNA inserted mutant pool. Anatomical observation revealed that the florets of the mutant showed elongated leafy paleas/lemmas and palea/lemma-like structures, just like multi-glumes. Among the 215 observed florets of the mutant, 14.27% were failed to produce pistil and stamens, 23.72% showed extra floret generated on the same rachilla, while 62.01% consisted of one to nine stamens and one to three pistils in a single floret. On the other hand, in some cases the transparent bulged vesile-like tissue could be observed at the basis of filament. The mutant showed glumaceous Iodicules, which prevented the florets from opening in natural conditions, while the absolute male and female sterility was an obvious character of the current mutant. Observation on the process of floral organ morphogenesis by a scanning electron microscopy （SEM） indicated that no phenotype difference in floret primordia was found between the wild-type and the mutant. Meanwhile, for the mutant, the beginning of stamen and pistil primordial differentiation was later than the wild type and the palea/lemma-like structure continued to differentiate after the formation of normal palea and lemma. Furthermore, in the mutant the asymmetrical division of floral primordial caused variation in the number of stamens and pistils. Therefore, the genetic analyses indicated that the mutation phenotype was a recessive trait controlled by a single gene and co-segregated with the T-DNA. Based on the phenotypic characteristics, it could be deduced that the mutant was the result of homeotic conversion from the function of the class E genes in ABCD model.展开更多
Polish wheat (Triticum polonicum) is a unique tetraploid wheat species characterized by an elongated outer glume. The genetic control of the long-glume trait by a single semi-dominant locus, P1 (from Polish wheat), wa...Polish wheat (Triticum polonicum) is a unique tetraploid wheat species characterized by an elongated outer glume. The genetic control of the long-glume trait by a single semi-dominant locus, P1 (from Polish wheat), was established more than 100 years ago, but the underlying causal gene and molecular nature remain elusive. Here, we report the isolation of VRT-A2, encoding an SVP-clade MADS-box transcription factor, as the P1 candidate gene. Genetic evidence suggests that in T. polonicum, a naturally occurring sequence rearrangement in the intron-1 region of VRT-A2 leads to ectopic expression of VRT-A2 in floral organs where the long-glume phenotype appears. Interestingly, we found that the intron-1 region is a key ON/OFF molecular switch for VRT-A2 expression, not only because it recruits transcriptional repressors, but also because it confers intron-mediated transcriptional enhancement. Genotypic analyses using wheat accessions indicated that the P1 locus is likely derived from a single natural mutation in tetraploid wheat, which was subsequently inherited by hexaploid T. petropavlovskyi. Taken together, our findings highlight the promoter-proximal intron variation as a molecular basis for phenotypic differentiation, and thus species formation in Triticum plants.展开更多
Rice(Oryza sativa)spikelets are a unique inflorescence structure and their development directly determines grain size and yield.Although many genes related to spikelet development have been reported,the molecular mech...Rice(Oryza sativa)spikelets are a unique inflorescence structure and their development directly determines grain size and yield.Although many genes related to spikelet development have been reported,the molecular mechanisms underlying this process have not been fully elucidated.In this study,we identified a new recessive rice mutant,lacking rudimentary glume 1(lrg1).The lrg1 spikelets only formed one rudimentary glume,which,along with the sterile lemmas,was homeotically transformed into lemma-like organs and acquired lemma identity.The transition from the spikelet to the floral meristem was delayed in the lrg1 mutant,resulting in the formation of an ectopic lemma-like organ between the sterile lemma and the terminal floret.In addition,we found that the abnormal lrg1 grain phenotype resulted from the alteration of cell numbers and the hull size.LRG1 encodes a ZOS4-06-C2H2 zinc-finger protein with the typical EAR motifs,and is expressed in all organs and tissues.LRG1 localizes to the nucleus and can interact with the TOPLESS-RELATED PROTEINs(TPRs)to repress the expressions of their downstream target genes.Taken together,our results reveal that LRG1 plays an important role in the regulation of spikelet organ identity and grain size.展开更多
The grass spikelet is a unique inflorescence structure that determines grain size.Although many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in ...The grass spikelet is a unique inflorescence structure that determines grain size.Although many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in rice are far from established.Here,we isolated rice gene,AGL1 that controlled grain size and determines the fate of the sterile lemma.Loss of function of AGL1 produced larger grains and reduced the size of the sterile lemma.Larger grains in the agl1 mutant were caused by a larger number of cells that were longer and wider than in the wild type.The sterile lemma in the mutant spikelet was converted to a rudimentary glume-like organ.Our findings showed that the AGL1(also named LAX1)protein positively regulated G1 expression,and negatively regulated NSG1 expression,thereby affecting the fate of the sterile lemma.Taken together,our results revealed that AGL1 played a key role in negative regulation of grain size by controlling cell proliferation and expansion,and supported the opinion that rudimentary glume and sterile lemma in rice are homologous organs.展开更多
Hybrid rice planting has been widely popularized and applied in the world. However, the high cost of seed production and the complicated procedures have become a bottleneck in the development of hybrid rice. The resea...Hybrid rice planting has been widely popularized and applied in the world. However, the high cost of seed production and the complicated procedures have become a bottleneck in the development of hybrid rice. The research progress on mixed sowing seed production techniques of hybrid rice was introduced from the aspects of rice resources creation, breeding, sowing seed technology research and cost benefit analysis. The production technology of the new mixed seeding combina- tion ＂Xinhunyou 6＂ was investigated, including the research and validation of benta- zon treatment period and dosage, mixing ratio of male and female parents, and the comparative test of different different sowing methods, which revealed that the mechanization technology of seed production of hybrid rice was mature and feasible and would be one of the most important development trend of technological devel- opment of hybrid rice production.展开更多
基金supported by the National Natural Science Foundation of China(31991210)the National Key Research and Development Program of China(2021YFD1200104)。
文摘Pigment accumulation is an important trait related to wheat domestication,but there remains a limited understanding of its molecular mechanism.The genetic control of the red glume trait by a dominant allele,Rg-B1,on 1BS was reported in the last century,but the underlying gene and its molecular basis remained elusive.Here,we identified TraesTSP1B01G005700(G57)encoding an R2R3-MYB transcription factor(TF)as the candidate Rg-B1 gene controlling red glume color by a combination of genome-wide association study(GWAS),bulked segregant RNA-sequencing(BSR-Seq),map-based cloning,and RNAseq.The Rg-B1 locus had zero to five duplicate copies only one of which had high transcriptional activity.Genetic evidence suggested that promoter sequence variation in G57 in the glume leads to high expression of G57,resulting in the red glume phenotype.G57 could bind to the promoters of anthocyanin synthesis genes TaCHS,TaF3'H,and TaUFGT,activating their expression and contributing to anthocyanin accumulation in wheat glume.G57 also played a pivotal role in up-regulating expression of genes TaDREB1C and TaFLO2 associated with increased grain weight,thereby causing increased grain weight.Our research offers a better understanding of the molecular basis of red glume in bread wheat.
基金supported by the Commercial Breeding Innovation of Sweet Glutinous Maize Varieties (cstc2016shms-ztzx80014)Fundamental Research Funds for the Central Universities (XDJK2018C052)the Major Project Research of Chongqing (cstc2016shms-ztzx80016, cstc2016shms-ztzx80017)
文摘The glume is an organ of the maize spikelet and plays important roles in anther and kernel development.Vestigial glume1(Vg1)is a classic mutant associated with ligule and glume development.Here we report the phenotypic characterization,fine mapping,and candidate gene analysis of the Vg1 mutant.Vg1 is a semi-dominant and pleiotropic gene,and also affects plant height,ear height,and tassel length.Vg1 ligule degeneration begins at the first leaf,and the Vg1 tassel and ear can be distinguished from those of wild-type plants when their lengths reach respectively 55 mm and 51 mm.Using a BC3 mapping population of 11,445 plants,we delimited the Vg1 functional site to an interval of 7.4 kb,flanked by the markers InDelLM and CRM6.A putative cyclopropane fatty-acid synthase gene(ZmCPA-FAS1)was hypothesized to underlie the mutant phenotype.We detected a Helitron insertion in the sixth intron of ZmCPAFAS1.Its presence caused abnormal alternative splicing of ZmCPA-FAS1 that conferred new characteristics on the Vg1 mutant.These findings are a basis for further discovery of the molecularmechanism underlying glume development and a potential guide formaize breeding of small-glume varieties,especially sweet corn breeding.
基金supported by grants from the Ministry of Sciences and Technology of China (No. 2008ZX08009-003 and 2009CB118500)the National Natural Sci-ence Foundation of China (No. 30621001 and 30900885)
文摘Although there is evident homology among reproductive organs when comparing Poaceae （grass） and eudicots, the identity of grass specific organs, such as lodicules, palea, lemma, and glumes has been the subject of a vast and largely inconclusive discussion. Here we provide some direct evidence to support the idea that the empty glumes of rice （Oryza sativa） are counterparts of lemmas. We show that the development of empty glumes is regulated by ELE （elongated empty glume）, which belongs to a plant specific novel gene family. Mutations at the ELE locus cause elongated empty glumes, which mimic the lemmas and have the epidermal morphology of lemmas with four or five vascular bundles. As a nuclear-localized gene, ELE is specifically expressed at the empty glumes of immature spikelets, and its ectopic expression causes many floral development defects, including lemma-like palea, extra palea-like structures, elongated lodicules, extra stamens and stigmas. Our result suggests that empty glumes are lemmas of the sterile florets located at the lateral side of the rice spikelet, and ELE acts as a regulator restraining its growth to maintain its small size in wild-type plants.
基金supported by a Chongqing Postdoctoral Science Foundation funded project (Xm201344)China Postdoctoral Science Foundation funded project (2014M552303)Fundamental Research Funds for the Central Universities (XDJK2013C023, 2362015xk05)
文摘The maize mutant gene Vestigial glume 1(Vg1) has been fine-mapped to a narrow region by map-based cloning and the candidate gene for Vg1 spanned 19.5 kb. Here we report Vg1 genomic fosmid library construction and screening. The fosmid library of Vg1 consisted of574,000 clones with an average insert size of 36.4 kb, representing 7.9-fold coverage of the maize genome. Fosmid stability assays indicated that clones were stable during propagation in the fosmid system. Using Vg1 candidate gene-specific primers, a positive clone was successfully identified. This discovery will pave the way for identifying the function of Vg1 in maize development.
基金Project supported by the National Key Basic Research Development Program of the Ministry of Science and Technology of China(Grant Nos.2001CB109002,2005CB120802)the National High-Techhology Research and Development Program of China(Grant No.2005AA2710330)+2 种基金the Science Foundation of Shanghai Municipal Commission of Science and Technology(Grant Nos.03JC14061,03DJ14016)the Program for New Century Excellent Talents in University(Grant No.NCET-040403)the Shuguang Plan of Shanghai Education Development Foundation(Grant No.04SG15)
文摘A rice mutant with Yaponica 9522 cultivar background Oryza sativa extraordinary glume 1 （Oseg 1） was identified from the M2 mutant pool mutagenized by ^60Co γ-ray. Compared with wild type plants, Oseg 1 developed longer empty glumes and rudimentary glumes. In some Oseg 1 mutants, the number of stamens of flowers was reduced and leaf-like lodicules occurred, and excessive lemma/palea-like organ could be observed in some mutant spikelets. This indicated that OsEG1 could regulate the development of rudimentary glumes, empty glumes, lemma/palea, lodicules, and stamens. Genetic analysis indicated that Oseg 1 came from a single recessive genetic locus. To clone OsEG1 gene, F2 population was constructed by a cross between Oseg 1 （Japonica） and Guangluai4 （Indica）. Using map-based cloning approach, OsEG1 was mapped on chromosome 4, between INDEL marker OS407 and WHM0466 with genetic distance of 2.0 cm and 1.0 cm, respectively. These results are useful for further cloning and functional analysis of the OsEG1 gene.
文摘A multi-glume （mg） mutant was obtained by screening the T-DNA inserted mutant pool. Anatomical observation revealed that the florets of the mutant showed elongated leafy paleas/lemmas and palea/lemma-like structures, just like multi-glumes. Among the 215 observed florets of the mutant, 14.27% were failed to produce pistil and stamens, 23.72% showed extra floret generated on the same rachilla, while 62.01% consisted of one to nine stamens and one to three pistils in a single floret. On the other hand, in some cases the transparent bulged vesile-like tissue could be observed at the basis of filament. The mutant showed glumaceous Iodicules, which prevented the florets from opening in natural conditions, while the absolute male and female sterility was an obvious character of the current mutant. Observation on the process of floral organ morphogenesis by a scanning electron microscopy （SEM） indicated that no phenotype difference in floret primordia was found between the wild-type and the mutant. Meanwhile, for the mutant, the beginning of stamen and pistil primordial differentiation was later than the wild type and the palea/lemma-like structure continued to differentiate after the formation of normal palea and lemma. Furthermore, in the mutant the asymmetrical division of floral primordial caused variation in the number of stamens and pistils. Therefore, the genetic analyses indicated that the mutation phenotype was a recessive trait controlled by a single gene and co-segregated with the T-DNA. Based on the phenotypic characteristics, it could be deduced that the mutant was the result of homeotic conversion from the function of the class E genes in ABCD model.
基金This work was supported by grants from the National Natural Science Foundation of China(32072055,31991210,and 91935304).
文摘Polish wheat (Triticum polonicum) is a unique tetraploid wheat species characterized by an elongated outer glume. The genetic control of the long-glume trait by a single semi-dominant locus, P1 (from Polish wheat), was established more than 100 years ago, but the underlying causal gene and molecular nature remain elusive. Here, we report the isolation of VRT-A2, encoding an SVP-clade MADS-box transcription factor, as the P1 candidate gene. Genetic evidence suggests that in T. polonicum, a naturally occurring sequence rearrangement in the intron-1 region of VRT-A2 leads to ectopic expression of VRT-A2 in floral organs where the long-glume phenotype appears. Interestingly, we found that the intron-1 region is a key ON/OFF molecular switch for VRT-A2 expression, not only because it recruits transcriptional repressors, but also because it confers intron-mediated transcriptional enhancement. Genotypic analyses using wheat accessions indicated that the P1 locus is likely derived from a single natural mutation in tetraploid wheat, which was subsequently inherited by hexaploid T. petropavlovskyi. Taken together, our findings highlight the promoter-proximal intron variation as a molecular basis for phenotypic differentiation, and thus species formation in Triticum plants.
基金supported by the Zhejiang Natural Science Foundation(LY18C130007)the National Natural Science Foundation of China(91735304)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund of China National Rice Research Institute(2017RG001-4)the National Science and Technology Major Project(2016ZX08009003-003-008)。
文摘Rice(Oryza sativa)spikelets are a unique inflorescence structure and their development directly determines grain size and yield.Although many genes related to spikelet development have been reported,the molecular mechanisms underlying this process have not been fully elucidated.In this study,we identified a new recessive rice mutant,lacking rudimentary glume 1(lrg1).The lrg1 spikelets only formed one rudimentary glume,which,along with the sterile lemmas,was homeotically transformed into lemma-like organs and acquired lemma identity.The transition from the spikelet to the floral meristem was delayed in the lrg1 mutant,resulting in the formation of an ectopic lemma-like organ between the sterile lemma and the terminal floret.In addition,we found that the abnormal lrg1 grain phenotype resulted from the alteration of cell numbers and the hull size.LRG1 encodes a ZOS4-06-C2H2 zinc-finger protein with the typical EAR motifs,and is expressed in all organs and tissues.LRG1 localizes to the nucleus and can interact with the TOPLESS-RELATED PROTEINs(TPRs)to repress the expressions of their downstream target genes.Taken together,our results reveal that LRG1 plays an important role in the regulation of spikelet organ identity and grain size.
基金supported by the National Natural Science Foundation of China(32372118,32188102,32071993)the Qian Qian Academician Workstation,Specific Research Fund of the Innovation Platform for Academicians in Hainan Province(YSPTZX202303)+1 种基金Key Research and Development Program of Zhejiang Province(2021C02056)Hainan Seed Industry Laboratory,China(B21HJ0220)。
文摘The grass spikelet is a unique inflorescence structure that determines grain size.Although many genetic factors have been well characterized for grain size and glume development,the underlying molecular mechanisms in rice are far from established.Here,we isolated rice gene,AGL1 that controlled grain size and determines the fate of the sterile lemma.Loss of function of AGL1 produced larger grains and reduced the size of the sterile lemma.Larger grains in the agl1 mutant were caused by a larger number of cells that were longer and wider than in the wild type.The sterile lemma in the mutant spikelet was converted to a rudimentary glume-like organ.Our findings showed that the AGL1(also named LAX1)protein positively regulated G1 expression,and negatively regulated NSG1 expression,thereby affecting the fate of the sterile lemma.Taken together,our results revealed that AGL1 played a key role in negative regulation of grain size by controlling cell proliferation and expansion,and supported the opinion that rudimentary glume and sterile lemma in rice are homologous organs.
基金Supported by the National High-tech R&D Program(863 Program)(2014AA10A603)the Key Science and Technology Program during the"13thFive Year Plan"of Anhui Province(1604a0702008)+1 种基金the Special Fund for Agro-scientific Research in the Public Interest(201503130)the Project for the Team of Science and Technology Innovation of Anhui Academy of Agricultural Sciences(15C0108)~~
文摘Hybrid rice planting has been widely popularized and applied in the world. However, the high cost of seed production and the complicated procedures have become a bottleneck in the development of hybrid rice. The research progress on mixed sowing seed production techniques of hybrid rice was introduced from the aspects of rice resources creation, breeding, sowing seed technology research and cost benefit analysis. The production technology of the new mixed seeding combina- tion ＂Xinhunyou 6＂ was investigated, including the research and validation of benta- zon treatment period and dosage, mixing ratio of male and female parents, and the comparative test of different different sowing methods, which revealed that the mechanization technology of seed production of hybrid rice was mature and feasible and would be one of the most important development trend of technological devel- opment of hybrid rice production.
