Pre-harvest sprouting(PHS)is a disadvantageous trait in cereal production worldwide,causing large economic losses each year.Its regulation mechanism is still unclear.We generated the Oryza sativa Viviparous1(OsVP1)mut...Pre-harvest sprouting(PHS)is a disadvantageous trait in cereal production worldwide,causing large economic losses each year.Its regulation mechanism is still unclear.We generated the Oryza sativa Viviparous1(OsVP1)mutant using gene editing technique,which shows increased PHS compared with that of the wild type Nipponbare.OsVP1 is localized mainly in the nucleus and expressed in various tissues and organs.Expression of Seed dormancy 4(Sdr4),a key gene controlling PHS,was sharply reduced in OsVP1 mutants.OsVP1 bound to the specific motif CACCTG in the promoter of Sdr4 and activated its expression in rice protoplasts.Overexpression of Sdr4 reduced the high seed germination rate of OsVP1 mutant cr-osvp1-1,showing that Sdr4 acts as a downstream target of OsVP1.Both OsVP1 and Sdr4 loss-of-function mutants were insensitive to exogenous ABA and employed the ABA signaling pathway in regulating seed dormancy.These findings shed light on the control of seed dormancy aimed at preventing PHS in rice.展开更多
Pre-harvest sprouting(PHS),which reduces grain yield and quality,is controlled by seed dormancy genes.Because few dormancy-related genes have been cloned,the genetic basis of seed dormancy in rice(Oryza sativa L.)rema...Pre-harvest sprouting(PHS),which reduces grain yield and quality,is controlled by seed dormancy genes.Because few dormancy-related genes have been cloned,the genetic basis of seed dormancy in rice(Oryza sativa L.)remains unclear.Here,we performed a genome-wide association study and linkage mapping to dissect the genetic basis of seed dormancy in rice.Our findings suggest that Seed Dormancy4(Sdr4),a central modulator of seed dormancy,integrates the abscisic acid and gibberellic acid signaling pathways at the transcriptional level.Haplotype analysis revealed that three Sdr4 alleles in rice cultivars already existed in ancestral Oryza rufipogon accessions.Furthermore,like the semi-dwarf 1(SD1)and Rc loci,Sdr4 underwent selection during the domestication and improvement of Asian cultivated rice.The distribution frequency of the Sdr4-n allele in different locations in Asia is negatively associated with local annual temperature and precipitation.Finally,we developed functional molecular markers for Sdr4,SD1,and Rc for use in molecular breeding.Our results provide clues about the molecular basis of Sdr4-regulated seed dormancy.Moreover,these findings provide guidance for utilizing the favorable alleles of Sdr4 and Rc to synergistically boost PHS resistance,yield,and quality in modern rice varieties.展开更多
Repression of embryonic traits during the seedto-seedling phase transition requires the inactivation of master transcription factors associated with embryogenesis.How the timing of such inactivation is controlled is u...Repression of embryonic traits during the seedto-seedling phase transition requires the inactivation of master transcription factors associated with embryogenesis.How the timing of such inactivation is controlled is unclear.Here,we report on a novel transcriptional corepressor,Arabidopsis thaliana SDR4L,that forms a feedback inhibition loop with the master transcription factors LEC1 and ABI3 to repress embryonic traits post-imbibition.LEC1 and ABI3 regulate their own expression by inducing AtSDR4L during mid to late embryogenesis.AtSDR4L binds to sites upstream of LEC1 and ABI4,and these transcripts are upregulated in Atsdr4l seedlings.Atsdr4 l seedlings phenocopy a LEC1 overexpressor.The embryonic traits of Atsdr4l can be partially rescued by impairing LEC1 or ABI3.The penetrance and expressivity of the Atsdr4l phenotypes depend on both developmental and external cues,demonstrating the importance of AtSDR4L in seedling establishment under suboptimal conditions.展开更多
基金supported by grants from the National Major Science and Technology Program on New GMO Organism Variety Breeding(2016ZX08001-001)Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS)。
文摘Pre-harvest sprouting(PHS)is a disadvantageous trait in cereal production worldwide,causing large economic losses each year.Its regulation mechanism is still unclear.We generated the Oryza sativa Viviparous1(OsVP1)mutant using gene editing technique,which shows increased PHS compared with that of the wild type Nipponbare.OsVP1 is localized mainly in the nucleus and expressed in various tissues and organs.Expression of Seed dormancy 4(Sdr4),a key gene controlling PHS,was sharply reduced in OsVP1 mutants.OsVP1 bound to the specific motif CACCTG in the promoter of Sdr4 and activated its expression in rice protoplasts.Overexpression of Sdr4 reduced the high seed germination rate of OsVP1 mutant cr-osvp1-1,showing that Sdr4 acts as a downstream target of OsVP1.Both OsVP1 and Sdr4 loss-of-function mutants were insensitive to exogenous ABA and employed the ABA signaling pathway in regulating seed dormancy.These findings shed light on the control of seed dormancy aimed at preventing PHS in rice.
基金supported by the National Natural Science Foundation of China (32001612)the Science, Technology and Innovation Commission of Shenzhen Municipality (JCYJ20180306173702268 and KCXFZ20201221173203009)+2 种基金Key-Area Research and Development Program of Guangdong Province (2021B0707010006)Dapeng New District Science and Technology Program (KJYF202101-09 and RCTD20180102)Guangdong Basic and Applied Basic Research Foundation (2019A1515110966)
文摘Pre-harvest sprouting(PHS),which reduces grain yield and quality,is controlled by seed dormancy genes.Because few dormancy-related genes have been cloned,the genetic basis of seed dormancy in rice(Oryza sativa L.)remains unclear.Here,we performed a genome-wide association study and linkage mapping to dissect the genetic basis of seed dormancy in rice.Our findings suggest that Seed Dormancy4(Sdr4),a central modulator of seed dormancy,integrates the abscisic acid and gibberellic acid signaling pathways at the transcriptional level.Haplotype analysis revealed that three Sdr4 alleles in rice cultivars already existed in ancestral Oryza rufipogon accessions.Furthermore,like the semi-dwarf 1(SD1)and Rc loci,Sdr4 underwent selection during the domestication and improvement of Asian cultivated rice.The distribution frequency of the Sdr4-n allele in different locations in Asia is negatively associated with local annual temperature and precipitation.Finally,we developed functional molecular markers for Sdr4,SD1,and Rc for use in molecular breeding.Our results provide clues about the molecular basis of Sdr4-regulated seed dormancy.Moreover,these findings provide guidance for utilizing the favorable alleles of Sdr4 and Rc to synergistically boost PHS resistance,yield,and quality in modern rice varieties.
基金funded by the National Science Foundation of China(31921001)the Beijing Outstanding University Discipline Program to Z.G.+4 种基金UBC Four Year Doctoral Fellowship to M.A.BC Graduate Scholarship to R.H.Bio Talent/SWPP funding to R.H.and E.L.UBC Kay Earle Memorial Botany Fund Fellowship to B.L.NSERC RGPIN-2019-05039 and CFI JELF/BCKDF 38187 to L.S.
文摘Repression of embryonic traits during the seedto-seedling phase transition requires the inactivation of master transcription factors associated with embryogenesis.How the timing of such inactivation is controlled is unclear.Here,we report on a novel transcriptional corepressor,Arabidopsis thaliana SDR4L,that forms a feedback inhibition loop with the master transcription factors LEC1 and ABI3 to repress embryonic traits post-imbibition.LEC1 and ABI3 regulate their own expression by inducing AtSDR4L during mid to late embryogenesis.AtSDR4L binds to sites upstream of LEC1 and ABI4,and these transcripts are upregulated in Atsdr4l seedlings.Atsdr4 l seedlings phenocopy a LEC1 overexpressor.The embryonic traits of Atsdr4l can be partially rescued by impairing LEC1 or ABI3.The penetrance and expressivity of the Atsdr4l phenotypes depend on both developmental and external cues,demonstrating the importance of AtSDR4L in seedling establishment under suboptimal conditions.
