Although considerable progress has been made in identifying the genes regulating accumulation of hormones that are involved in leaf senescence, only a few studies have focused on natural variations in jasmonates conte...Although considerable progress has been made in identifying the genes regulating accumulation of hormones that are involved in leaf senescence, only a few studies have focused on natural variations in jasmonates content and much less on the underlying genetic basis. Moreover, the epigenetic regulation of jasmonate-mediated leaf senescence remains largely unknown, in this study, we carried out metabolic profiling of a worldwide collection of rice accessions and demonstrated that there are substantial variations in jasmonate levels among these accessions. A subsequent metabolite-based genornewide association study identified candidates for two major quantitative genes （QTGs）, OsPME1 and OsTSD2, affecting the content of jasmonates. Further investigations using a series of relevant mutants and transgenic lines revealed the MeOH-jasmonata cascade plays an important role in regulating leaf senescence. Moreover, we showed that OsSRT1, one of the two Sir2 （silent information regugator 2） homologs in rice, negatively regulates leaf senescence by repressing expression of the biosynthetic genes of this metabolic cascade and at least particiaUy through histone H3K9 deacetylation of OsPME1. Taken together, our results indicate that the MeOH-jasmonates cascade and its epigenetic regulation are crucial for controlling leaf senescence process in rice.展开更多
Although natural variations in rice flavonoids exist, and biochemical characterization of a few flavonoid glycosyltransferases has been reported, few studies focused on natural variations in tricin-lignan-glycosides a...Although natural variations in rice flavonoids exist, and biochemical characterization of a few flavonoid glycosyltransferases has been reported, few studies focused on natural variations in tricin-lignan-glycosides and their underlying genetic basis. In this study, we carried out metabolic profiling of tricin-lignan-glycosides and identified a major quantitative gene annotated as a UDPdependent glycosyltransferase OsUGT706C2 by metabolite-based genome-wide association analysis. The putative flavonoid glycosyltransferase OsUGT706C2 was characterized as a flavonoid 7-O-glycosyltransferas in vitro and in vivo. Although the in vitro enzyme activity of OsUGT706C2 was similar to that of OsUGT706D1, the expression pattern and induced expression profile of OsUGT706C2 were very different from those of OsUGT706D1. Besides, OsUGT706C2 was specifically induced by UV-B. Constitutive expression of OsUGT706C2 in rice may modulate phenylpropanoid metabolism at both the transcript and metabolite levels. Furthermore, overexpressing OsUGT706C2 can enhance UV-B tolerance by promoting ROS scavenging in rice. Our findings might make it possible to use the glycosyltransferase OsUGT706C2 for crop improvement with respect to UVB adaptation and/or flavonoid accumulation, which may contribute to stable yield.展开更多
As one of the most important crops in the world,rice(Oryza sativa)is a model plant for metabolome research.Although many studies have focused on the analysis of specific tissues,the changes in metab-olite abundance ac...As one of the most important crops in the world,rice(Oryza sativa)is a model plant for metabolome research.Although many studies have focused on the analysis of specific tissues,the changes in metab-olite abundance across the entire life cycle have not yet been determined.In this study,combining both tar-geted and nontargeted metabolite profiling methods,a total of 825 annotated metabolites were quantified in rice samples from different tissues covering the entire life cycle.The contents of metabolites in different tissues of rice were significantly different,with various metabolites accumulating in the plumule and radicle during seed germination.Combining these data with transcriptome data obtained from the same time period,we constructed the Rice Metabolic Regulation Network.The metabolites and co-expressed genes were further divided into 12 clusters according to their accumulation patterns,with members within each cluster displaying a uniform and clear pattern of abundance across development.Using this dataset,we established a comprehensive metabolic profile of the rice life cycle and used two independent strategies to identify novel transcription factors-namely the use of known regulatory genes as bait to screen for new networks underlying lignin metabolism and the unbiased identification of new glycerophospholipid metabolism regulators on the basis of tissue specificity.This study thus demonstrates how guilt-by-association analysis of metabolome and transcriptome data spanning the entire life cycle in cereal crops provides novel resources and tools to aid in understanding the mechanisms underlying important agro-nomic traits.展开更多
Dear Editor,Branched-chain amino acids(BCAAs)are essential amino acids that must be obtained from the diet for humans and animals.Branched-chain amino acid transaminases(BCATs)catalyze a key step in the BCAA synthesis...Dear Editor,Branched-chain amino acids(BCAAs)are essential amino acids that must be obtained from the diet for humans and animals.Branched-chain amino acid transaminases(BCATs)catalyze a key step in the BCAA synthesis pathway,however,little is known about their biological roles in planta.In this study,we functionally characterized two BCATs,OsBCAT4 and OsBCAT5,in rice and showed that they regulate the development of rice roots by affecting the levels of mineral elements.展开更多
Plants produce specialized metabolites to adapt to the ever-changing environments.Flavonoids are antioxidants essential for growth,development,and breeding with increased stress resistance in crops.However,the mechani...Plants produce specialized metabolites to adapt to the ever-changing environments.Flavonoids are antioxidants essential for growth,development,and breeding with increased stress resistance in crops.However,the mechanism of the involvement of flavonoids in ultraviolet-B(UV-B)stress in rice(Oryza sativa)is largely unknown.In this study,we cloned and functionally identified a receptor-like kinase(OsRLCK160)and a bZIP transcription factor(OsbZIP48)positively regulating flavonoid accumulation through metabolite-based genome-wide association study of the flavonoid content in rice.Meanwhile,OsRLCK160 interacted with and phosphorylated OsbZIP48 to regulate the flavonoid accumulation and participate in UV-B tolerance in rice.Our study indicates the importance of applying OsRLCK160 and OsbZIP48 to advance the fundamental understanding of stable rice production and breed UV-B-tolerant rice varieties,which may contribute to breeding high-yield rice varieties.展开更多
基金This work was supported by the State Key Program of the National Natural Science Foundation of China （no. 31530052）, the Major State Basic Research Development Program of China （973 Program, no. 2013CB127001）, the National High Technology R＆D Program of China （863 Program, no. 2012AA10A304）, and the Program from Fundamental Research Funds for the Central Universities （no. 2662015PY196）.
文摘Although considerable progress has been made in identifying the genes regulating accumulation of hormones that are involved in leaf senescence, only a few studies have focused on natural variations in jasmonates content and much less on the underlying genetic basis. Moreover, the epigenetic regulation of jasmonate-mediated leaf senescence remains largely unknown, in this study, we carried out metabolic profiling of a worldwide collection of rice accessions and demonstrated that there are substantial variations in jasmonate levels among these accessions. A subsequent metabolite-based genornewide association study identified candidates for two major quantitative genes （QTGs）, OsPME1 and OsTSD2, affecting the content of jasmonates. Further investigations using a series of relevant mutants and transgenic lines revealed the MeOH-jasmonata cascade plays an important role in regulating leaf senescence. Moreover, we showed that OsSRT1, one of the two Sir2 （silent information regugator 2） homologs in rice, negatively regulates leaf senescence by repressing expression of the biosynthetic genes of this metabolic cascade and at least particiaUy through histone H3K9 deacetylation of OsPME1. Taken together, our results indicate that the MeOH-jasmonates cascade and its epigenetic regulation are crucial for controlling leaf senescence process in rice.
基金supported by the Foundation for the Major Science and Technology Program of Ningxia Hui Autonomous Region (2016BZ06)the State Key Program of National Natural Science Foundation of China (31530052)+2 种基金the National Science Fund for Distinguished Young Scholars (31625021)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (31821005)the Hainan University Startup Fund (KYQD(ZR)1866) to JL。
文摘Although natural variations in rice flavonoids exist, and biochemical characterization of a few flavonoid glycosyltransferases has been reported, few studies focused on natural variations in tricin-lignan-glycosides and their underlying genetic basis. In this study, we carried out metabolic profiling of tricin-lignan-glycosides and identified a major quantitative gene annotated as a UDPdependent glycosyltransferase OsUGT706C2 by metabolite-based genome-wide association analysis. The putative flavonoid glycosyltransferase OsUGT706C2 was characterized as a flavonoid 7-O-glycosyltransferas in vitro and in vivo. Although the in vitro enzyme activity of OsUGT706C2 was similar to that of OsUGT706D1, the expression pattern and induced expression profile of OsUGT706C2 were very different from those of OsUGT706D1. Besides, OsUGT706C2 was specifically induced by UV-B. Constitutive expression of OsUGT706C2 in rice may modulate phenylpropanoid metabolism at both the transcript and metabolite levels. Furthermore, overexpressing OsUGT706C2 can enhance UV-B tolerance by promoting ROS scavenging in rice. Our findings might make it possible to use the glycosyltransferase OsUGT706C2 for crop improvement with respect to UVB adaptation and/or flavonoid accumulation, which may contribute to stable yield.
基金supported by the Hainan Province Major Research Project(modern agricuture,ZDYF2020066)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China 01821005)+1 种基金the Hainan Major Science and Technolgy Project(No,ZDKJ202002).the Hainan Academician Innovaton Platform(HD-YSZX-202003)and the Hainan University Startup Fund(KYQD(ZR)1866).
文摘As one of the most important crops in the world,rice(Oryza sativa)is a model plant for metabolome research.Although many studies have focused on the analysis of specific tissues,the changes in metab-olite abundance across the entire life cycle have not yet been determined.In this study,combining both tar-geted and nontargeted metabolite profiling methods,a total of 825 annotated metabolites were quantified in rice samples from different tissues covering the entire life cycle.The contents of metabolites in different tissues of rice were significantly different,with various metabolites accumulating in the plumule and radicle during seed germination.Combining these data with transcriptome data obtained from the same time period,we constructed the Rice Metabolic Regulation Network.The metabolites and co-expressed genes were further divided into 12 clusters according to their accumulation patterns,with members within each cluster displaying a uniform and clear pattern of abundance across development.Using this dataset,we established a comprehensive metabolic profile of the rice life cycle and used two independent strategies to identify novel transcription factors-namely the use of known regulatory genes as bait to screen for new networks underlying lignin metabolism and the unbiased identification of new glycerophospholipid metabolism regulators on the basis of tissue specificity.This study thus demonstrates how guilt-by-association analysis of metabolome and transcriptome data spanning the entire life cycle in cereal crops provides novel resources and tools to aid in understanding the mechanisms underlying important agro-nomic traits.
基金supported by the National Science Fund for Distinguished Young Scholars (31625021)the State Key Program of National Natural Science Foundation of China (31530052)+2 种基金the Ministry of Science and Technology of China (2016YFD0100500) to J.L.the China Postdoctoral Science Foundation (2017M610480)the National Natural Science Foundation of China (31800203) to C.J.
文摘Dear Editor,Branched-chain amino acids(BCAAs)are essential amino acids that must be obtained from the diet for humans and animals.Branched-chain amino acid transaminases(BCATs)catalyze a key step in the BCAA synthesis pathway,however,little is known about their biological roles in planta.In this study,we functionally characterized two BCATs,OsBCAT4 and OsBCAT5,in rice and showed that they regulate the development of rice roots by affecting the levels of mineral elements.
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(31821005)the Hainan Major Science and Technology Project(ZDKJ202002)+1 种基金the Key Research and Development Program of Hainan(ZDYF2020066)the Hainan University Startup Fund(KYQD(ZR)1866)。
文摘Plants produce specialized metabolites to adapt to the ever-changing environments.Flavonoids are antioxidants essential for growth,development,and breeding with increased stress resistance in crops.However,the mechanism of the involvement of flavonoids in ultraviolet-B(UV-B)stress in rice(Oryza sativa)is largely unknown.In this study,we cloned and functionally identified a receptor-like kinase(OsRLCK160)and a bZIP transcription factor(OsbZIP48)positively regulating flavonoid accumulation through metabolite-based genome-wide association study of the flavonoid content in rice.Meanwhile,OsRLCK160 interacted with and phosphorylated OsbZIP48 to regulate the flavonoid accumulation and participate in UV-B tolerance in rice.Our study indicates the importance of applying OsRLCK160 and OsbZIP48 to advance the fundamental understanding of stable rice production and breed UV-B-tolerant rice varieties,which may contribute to breeding high-yield rice varieties.
