Reserve starch of cereal crop accounts for about 70%of grain endosperm and acts as an important human carbohydrate resource worldwide.Wheat reserve starch is synthesized by enzymatic machinery in endosperm cells.To id...Reserve starch of cereal crop accounts for about 70%of grain endosperm and acts as an important human carbohydrate resource worldwide.Wheat reserve starch is synthesized by enzymatic machinery in endosperm cells.To identify genes involved in starch biosynthesis,we constructed 30 RNA-Seq libraries of 10 endosperm-development periods and performed expression and localization analyses.Of 166 endosperm-expressed homologs of starch biosynthesis-related genes,74 showed expression correlated with reserve starch accumulation,including 26 with expected subcellular distribution and higher expression than their isoforms.The key proteins SUS3,UGP1,cAGPase,and Bt1-3 formed the main metabolic pathway and contributed the major substrates for starch processing in amyloplasts.Important isoforms,key pathway proteins,and the main carbon flux toward starch formation in the reserve starch biosynthesis pathway were identified.Based on a coexpression analysis,a library of 425 transcription factors was produced to screen for common regulators.TaMYB44 had features of transcription factors and bound to TaSUT1,TaSSIIIa,TaBEIIa,TaISA1,and TaBEIIb promoters in yeast,suggesting that the gene is a pathway regulator.This study sheds light on understanding the mechanism of reserve starch biosynthesis and will be helpful for increasing starch content in wheat endosperm via biotechnological strategies.展开更多
Rice is a major crop susceptible to chilling stress.The identification of quantitative trait loci and genes for cold tolerance is crucial for the rice breeding.Of 30 quantitative-trait loci affecting seedling cold tol...Rice is a major crop susceptible to chilling stress.The identification of quantitative trait loci and genes for cold tolerance is crucial for the rice breeding.Of 30 quantitative-trait loci affecting seedling cold tolerance identified in a genome-wide association study of 540 rice accessions,OsbZIP72 was assigned as the causative gene for one,qCTS9.1.A single-nucleotide polymorphism in its promoter accounted for variation in expression between indica and japonica subspecies.The favorable haplotype of OsbZIP72 originated in wild rice and contributed to the expansion of japonica rice to colder habitats.OsbZIP72 positively regulates genes coding reactive oxygen species(ROS)-scavenging proteins and maintains intracellular ROS homeostasis.These findings not only enhanced our understanding of environmental adaptation but also provide novel genetic resources and potential targets for molecular design breeding for cold tolerance in rice.展开更多
Drought is a major factor restricting the production of rice(Oryza sativa L.).The identification of natural variants for drought stress-related genes is an important step toward developing genetically improved rice va...Drought is a major factor restricting the production of rice(Oryza sativa L.).The identification of natural variants for drought stress-related genes is an important step toward developing genetically improved rice varieties.Here,we characterized a member of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)family,OsSPL10,as a transcription factor involved in the regulation of drought tolerance in rice.OsSPL10 appears to play a vital role in drought tolerance by controlling reactive oxygen species(ROS)production and stomatal movements.Haplotype and allele frequency analyses of OsSPL10 indicated that most upland rice and improved lowland rice varieties harbor the OsSPL10Hap1allele,whereas the OsSPL10Hap2allele was mainly present in lowland and landrace rice varieties.Importantly,we demonstrated that the varieties with the OsSPL10Hap1allele showed low expression levels of OsSPL10 and its downstream gene,OsNAC2,which decreases the expression of OsAP37 and increases the expression of OsCOX11,thus preventing ROS accumulation and programmed cell death(PCD).Furthermore,the knockdown or knockout of OsSPL10 induced fast stomatal closure and prevented water loss,thereby improving drought tolerance in rice.Based on these observations,we propose that OsSPL10 confers drought tolerance by regulating OsNAC2 expression and that OsSPL10Hap1could be a valuable haplotype for the genetic improvement of drought tolerance in rice.展开更多
Trichomes function in plant defenses against biotic and abiotic stresses;examination of glabrous lines,which lack trichomes,has revealed key aspects of trichome development and function.Tests of allelism in 51 glabrou...Trichomes function in plant defenses against biotic and abiotic stresses;examination of glabrous lines,which lack trichomes,has revealed key aspects of trichome development and function.Tests of allelism in 51 glabrous rice(Oryza sativa)accessions collected worldwide identified OsSPL10 and OsWOX3B as regulators of trichome development in rice.Here,we report that OsSPL10 acts as a transcriptional regulator controlling trichome development.Haplotype and transient expression analyses revealed that variation in the approximately 700-bp OsSPL10 promoter region is the primary cause of the glabrous phenotype in the indica cultivar WD-17993.Disruption of OsSPL10 by genome editing decreased leaf trichome density and length in the NIL-HL6 background.Plants with genotype OsSPL10^(WD-17993)/HL6 generated by crossing WD-17993 with NIL-HL6 also had fewer trichomes in the glumes.HAIRY LEAF6(HL6)encodes another transcription factor that regulates trichome initiation and elongation,and OsSPL10 directly binds to the HL6 promoter to regulate its expression.Moreover,the transcript levels of auxin-related genes,such as OsYUCCA5 and OsPIN-FORMED1b,were altered in OsSPL10 overexpression and RNAi transgenic lines.Feeding tests using locusts(Locusta migratoria)demonstrated that non-glandular trichomes affect feeding by this herbivore.Our findings provide a molecular framework for trichome development and an ecological perspective on trichome functions.展开更多
Drought is a major environmental stress limiting crop yields worldwide.Upland rice(Oryza sativa)has evolved complex genetic mechanisms for adaptative growth under drought stress.However,few genetic variants that media...Drought is a major environmental stress limiting crop yields worldwide.Upland rice(Oryza sativa)has evolved complex genetic mechanisms for adaptative growth under drought stress.However,few genetic variants that mediate drought resistance in upland rice have been identified,and little is known about the evolution of this trait during rice domestication.In this study,using a genome-wide association study we identified ROOT LENGTH 1(RoLe1)that controls rice root length and drought resistance.We found that a G-to-T polymorphism in the RoLe1 promoter causes increased binding of the transcription factor OsNAC41 and thereby enhanced expression of RoLe1.We further showed that RoLe1 interacts with OsAGAP,an ARF-GTPase activating protein involved in auxin-dependent root development,and interferes with its function to modulate root development.Interestingly,RoLe1 could enhance crop yield by increasing the seed-setting rate under moderate drought conditions.Genomic evolutionary analysis revealed that a newly arisen favorable allelic variant,proRoLe1−526T,originated from the midwest Asia and was retained in upland rice during domestication.Collectively,our study identifies an OsNAC41-RoLe1-OsAGAP module that promotes upland rice root development and drought resistance,providing promising genetic targets for molecular breeding of drought-resistant rice varieties.展开更多
基金This research was supported the National Program on R&D of Transgenic Plants(2016ZX08009003-004)National Natural Science Foundation of China(31571652)the Youth Innovative Research Team of Capital Normal University.
文摘Reserve starch of cereal crop accounts for about 70%of grain endosperm and acts as an important human carbohydrate resource worldwide.Wheat reserve starch is synthesized by enzymatic machinery in endosperm cells.To identify genes involved in starch biosynthesis,we constructed 30 RNA-Seq libraries of 10 endosperm-development periods and performed expression and localization analyses.Of 166 endosperm-expressed homologs of starch biosynthesis-related genes,74 showed expression correlated with reserve starch accumulation,including 26 with expected subcellular distribution and higher expression than their isoforms.The key proteins SUS3,UGP1,cAGPase,and Bt1-3 formed the main metabolic pathway and contributed the major substrates for starch processing in amyloplasts.Important isoforms,key pathway proteins,and the main carbon flux toward starch formation in the reserve starch biosynthesis pathway were identified.Based on a coexpression analysis,a library of 425 transcription factors was produced to screen for common regulators.TaMYB44 had features of transcription factors and bound to TaSUT1,TaSSIIIa,TaBEIIa,TaISA1,and TaBEIIb promoters in yeast,suggesting that the gene is a pathway regulator.This study sheds light on understanding the mechanism of reserve starch biosynthesis and will be helpful for increasing starch content in wheat endosperm via biotechnological strategies.
基金supported by the grants from Biological Breeding-National Science and Technology Major Project (2023ZD0407104)National Natural Science Foundation of China (32372080)Yunnan Fundamental Research Project (202201AS070071).
文摘Rice is a major crop susceptible to chilling stress.The identification of quantitative trait loci and genes for cold tolerance is crucial for the rice breeding.Of 30 quantitative-trait loci affecting seedling cold tolerance identified in a genome-wide association study of 540 rice accessions,OsbZIP72 was assigned as the causative gene for one,qCTS9.1.A single-nucleotide polymorphism in its promoter accounted for variation in expression between indica and japonica subspecies.The favorable haplotype of OsbZIP72 originated in wild rice and contributed to the expansion of japonica rice to colder habitats.OsbZIP72 positively regulates genes coding reactive oxygen species(ROS)-scavenging proteins and maintains intracellular ROS homeostasis.These findings not only enhanced our understanding of environmental adaptation but also provide novel genetic resources and potential targets for molecular design breeding for cold tolerance in rice.
基金supported by grants from the National Natural Science Foundation of China(31861143007)the National Key R&D Program(2021YFD1200502)+1 种基金the Research Program of Sanya Yazhou Bay Science and Technology City(SYND-2022-16)the Project of Hainan Yazhou Bay Seed Lab(B21HJ0508)。
文摘Drought is a major factor restricting the production of rice(Oryza sativa L.).The identification of natural variants for drought stress-related genes is an important step toward developing genetically improved rice varieties.Here,we characterized a member of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE(SPL)family,OsSPL10,as a transcription factor involved in the regulation of drought tolerance in rice.OsSPL10 appears to play a vital role in drought tolerance by controlling reactive oxygen species(ROS)production and stomatal movements.Haplotype and allele frequency analyses of OsSPL10 indicated that most upland rice and improved lowland rice varieties harbor the OsSPL10Hap1allele,whereas the OsSPL10Hap2allele was mainly present in lowland and landrace rice varieties.Importantly,we demonstrated that the varieties with the OsSPL10Hap1allele showed low expression levels of OsSPL10 and its downstream gene,OsNAC2,which decreases the expression of OsAP37 and increases the expression of OsCOX11,thus preventing ROS accumulation and programmed cell death(PCD).Furthermore,the knockdown or knockout of OsSPL10 induced fast stomatal closure and prevented water loss,thereby improving drought tolerance in rice.Based on these observations,we propose that OsSPL10 confers drought tolerance by regulating OsNAC2 expression and that OsSPL10Hap1could be a valuable haplotype for the genetic improvement of drought tolerance in rice.
基金The research was supported by grants from the National Science Foundation of China(31271689)the Ministry of Science and Technology of China(2016YFD0100101-09).
文摘Trichomes function in plant defenses against biotic and abiotic stresses;examination of glabrous lines,which lack trichomes,has revealed key aspects of trichome development and function.Tests of allelism in 51 glabrous rice(Oryza sativa)accessions collected worldwide identified OsSPL10 and OsWOX3B as regulators of trichome development in rice.Here,we report that OsSPL10 acts as a transcriptional regulator controlling trichome development.Haplotype and transient expression analyses revealed that variation in the approximately 700-bp OsSPL10 promoter region is the primary cause of the glabrous phenotype in the indica cultivar WD-17993.Disruption of OsSPL10 by genome editing decreased leaf trichome density and length in the NIL-HL6 background.Plants with genotype OsSPL10^(WD-17993)/HL6 generated by crossing WD-17993 with NIL-HL6 also had fewer trichomes in the glumes.HAIRY LEAF6(HL6)encodes another transcription factor that regulates trichome initiation and elongation,and OsSPL10 directly binds to the HL6 promoter to regulate its expression.Moreover,the transcript levels of auxin-related genes,such as OsYUCCA5 and OsPIN-FORMED1b,were altered in OsSPL10 overexpression and RNAi transgenic lines.Feeding tests using locusts(Locusta migratoria)demonstrated that non-glandular trichomes affect feeding by this herbivore.Our findings provide a molecular framework for trichome development and an ecological perspective on trichome functions.
基金supported by the National Key Research and Development Program of China(2023YFF10004000)the National Natural Science Foundation of China(32401809)+1 种基金the key research projects of the Ministry of Science and Technology of the People's Republic of China(2021YFD1200502)the Hainan Yazhou Bay Seed Laboratory,and the China National Seed Group(B23YQ1517).
文摘Drought is a major environmental stress limiting crop yields worldwide.Upland rice(Oryza sativa)has evolved complex genetic mechanisms for adaptative growth under drought stress.However,few genetic variants that mediate drought resistance in upland rice have been identified,and little is known about the evolution of this trait during rice domestication.In this study,using a genome-wide association study we identified ROOT LENGTH 1(RoLe1)that controls rice root length and drought resistance.We found that a G-to-T polymorphism in the RoLe1 promoter causes increased binding of the transcription factor OsNAC41 and thereby enhanced expression of RoLe1.We further showed that RoLe1 interacts with OsAGAP,an ARF-GTPase activating protein involved in auxin-dependent root development,and interferes with its function to modulate root development.Interestingly,RoLe1 could enhance crop yield by increasing the seed-setting rate under moderate drought conditions.Genomic evolutionary analysis revealed that a newly arisen favorable allelic variant,proRoLe1−526T,originated from the midwest Asia and was retained in upland rice during domestication.Collectively,our study identifies an OsNAC41-RoLe1-OsAGAP module that promotes upland rice root development and drought resistance,providing promising genetic targets for molecular breeding of drought-resistant rice varieties.
