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
As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor Os...As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor OsbZIP01,which can suppress the expression of SD1 and regulate gibberellin(GA)biosynthesis in rice.Knockout mutants of OsbZIP01 exhibited increased plant height,while the overexpression lines showed a semi-dwarf phenotype and diminished germination rate.Furthermore,the semi-dwarf phenotype of OE-bZIP01,was caused by the reduced internode length,which was accompanied by a thin stem width.The predominant expression of OsbZIP01 was observed in leaves and sheaths.OsbZIP01 protein was localized in the nucleus and showed transcriptional repression activity.In addition,OsbZIP01 could directly bind to the promoter of the OsSD1 gene,and inhibit its transcription.The semi-dwarf phenotype of OE-bZIP01 could be rescued by exogenous GA_(3).Meanwhile,the bzip01 sd1 double mutant showed a shorter shoot length compared with the wild type,indicating that OsbZIP01 regulated plant growth mainly through the GA biosynthesis pathway.Collectively,OsbZIP01 negatively regulates GA biosynthesis by restraining SD1 transcription,thereby affecting plant growth and development.展开更多
A mechanized direct seeding of rice with less labor and water usage,has been widely adopted.However,this approach requires varieties that exhibit uniform seedling emergence.Mesocotyl elongation(ME)offers the main driv...A mechanized direct seeding of rice with less labor and water usage,has been widely adopted.However,this approach requires varieties that exhibit uniform seedling emergence.Mesocotyl elongation(ME)offers the main drive of fast emergence of rice seedlings from soils;nevertheless,its genetic basis remains unknown.Here,we identify a major rice quantitative trait locus Mesocotyl Elongation1(qME1),an allele of the Green Revolution gene Semi-Dwarf1(SD1),encoding GA20-oxidase for gibberellin(GA)biosynthesis.ME1 expression is strongly induced by soil depth and ethylene.When rice grains are direct-seeded in soils,the ethylene core signaling factor OsEIL1 directly promotes ME1 transcription,accelerating bioactive GA biosynthesis.The GAs further degrade the DELLA protein SLENDER RICE 1(SLR1),alleviating its inhibition of rice PHYTOCHROME-INTERACTING FACTOR-LIKE13(OsPIL13)to activate the downstream expansion gene OsEXPA4 and ultimately promote rice seedling ME and emergence.The ancient traits of long mesocotyl and strong emergence ability in wild rice and landrace were gradually lost in company with the Green Revolution dwarf breeding process,and an elite ME1-R allele(D349H)is found in some modern Geng varieties(long mesocotyl lengths)in northern China,which can be used in the direct seeding and dwarf breeding of Geng varieties.Furthermore,the ectopic and high expression of ME1 driven by mesocotyl-specific promoters resulted in rice plants that could be direct-seeded without obvious plant architecture or yield penalties.Collectively,we reveal the molecular mechanism of rice ME,and provide useful information for breeding new Green Revolution varieties with long mesocotyl suitable for direct-seeding practice.展开更多
The Smart Dragon 1(SD-1) launch vehicle is the first commercial rocket developed by China Academy of Launch Vehicle Technology(CALT), targeting to the international launch market for small satellites. As the smallest ...The Smart Dragon 1(SD-1) launch vehicle is the first commercial rocket developed by China Academy of Launch Vehicle Technology(CALT), targeting to the international launch market for small satellites. As the smallest launch vehicle in China at present, SD-1 is one of the most efficient solid boost rockets nationwide in terms of launch capacity. Compared with current domestic rockets, it provides remarkable access to space with a faster response, higher orbit-injection accuracy and better payload accommodation at a lower cost. On August 17, 2019, SD-1 completed its maiden flight and delivered three satellites into the desired Sun Synchronous Orbit(SSO) of 550 km accurately. In this article, a technical review of SD-1 is presented detailing the design concept and the use of state of the art technology throughout its development.展开更多
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supported by the National Natural Science Foundation of China(Grant No.32101763)China National Postdoctoral Program for Innovative Talents(Grant No.BX2021266)China Postdoctoral Science Foundation(Grant No.2021M692853).
文摘As the‘Green Revolution’gene,SD1(encoding GA20ox2),has been widely applied to improve yield in rice breeding.However,research on its transcriptional regulation is limited.Here,we identified a transcription factor OsbZIP01,which can suppress the expression of SD1 and regulate gibberellin(GA)biosynthesis in rice.Knockout mutants of OsbZIP01 exhibited increased plant height,while the overexpression lines showed a semi-dwarf phenotype and diminished germination rate.Furthermore,the semi-dwarf phenotype of OE-bZIP01,was caused by the reduced internode length,which was accompanied by a thin stem width.The predominant expression of OsbZIP01 was observed in leaves and sheaths.OsbZIP01 protein was localized in the nucleus and showed transcriptional repression activity.In addition,OsbZIP01 could directly bind to the promoter of the OsSD1 gene,and inhibit its transcription.The semi-dwarf phenotype of OE-bZIP01 could be rescued by exogenous GA_(3).Meanwhile,the bzip01 sd1 double mutant showed a shorter shoot length compared with the wild type,indicating that OsbZIP01 regulated plant growth mainly through the GA biosynthesis pathway.Collectively,OsbZIP01 negatively regulates GA biosynthesis by restraining SD1 transcription,thereby affecting plant growth and development.
基金supported by the National Natural Science Foundation of China(32188102 and 32101763)Zhejiang Provincial Science and Technology Project(2020R51007)+1 种基金the Key Research and Development Program of Zhejiang province(2022C02011)the Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-CACB-202402).
文摘A mechanized direct seeding of rice with less labor and water usage,has been widely adopted.However,this approach requires varieties that exhibit uniform seedling emergence.Mesocotyl elongation(ME)offers the main drive of fast emergence of rice seedlings from soils;nevertheless,its genetic basis remains unknown.Here,we identify a major rice quantitative trait locus Mesocotyl Elongation1(qME1),an allele of the Green Revolution gene Semi-Dwarf1(SD1),encoding GA20-oxidase for gibberellin(GA)biosynthesis.ME1 expression is strongly induced by soil depth and ethylene.When rice grains are direct-seeded in soils,the ethylene core signaling factor OsEIL1 directly promotes ME1 transcription,accelerating bioactive GA biosynthesis.The GAs further degrade the DELLA protein SLENDER RICE 1(SLR1),alleviating its inhibition of rice PHYTOCHROME-INTERACTING FACTOR-LIKE13(OsPIL13)to activate the downstream expansion gene OsEXPA4 and ultimately promote rice seedling ME and emergence.The ancient traits of long mesocotyl and strong emergence ability in wild rice and landrace were gradually lost in company with the Green Revolution dwarf breeding process,and an elite ME1-R allele(D349H)is found in some modern Geng varieties(long mesocotyl lengths)in northern China,which can be used in the direct seeding and dwarf breeding of Geng varieties.Furthermore,the ectopic and high expression of ME1 driven by mesocotyl-specific promoters resulted in rice plants that could be direct-seeded without obvious plant architecture or yield penalties.Collectively,we reveal the molecular mechanism of rice ME,and provide useful information for breeding new Green Revolution varieties with long mesocotyl suitable for direct-seeding practice.
文摘The Smart Dragon 1(SD-1) launch vehicle is the first commercial rocket developed by China Academy of Launch Vehicle Technology(CALT), targeting to the international launch market for small satellites. As the smallest launch vehicle in China at present, SD-1 is one of the most efficient solid boost rockets nationwide in terms of launch capacity. Compared with current domestic rockets, it provides remarkable access to space with a faster response, higher orbit-injection accuracy and better payload accommodation at a lower cost. On August 17, 2019, SD-1 completed its maiden flight and delivered three satellites into the desired Sun Synchronous Orbit(SSO) of 550 km accurately. In this article, a technical review of SD-1 is presented detailing the design concept and the use of state of the art technology throughout its development.
