Grain size and leaf angle are key agronomic traits that determine final yields in rice.However,the underlying molecular mechanisms are not well understood.Here we demonstrate that the Oryza sativa Mitogen Activated Pr...Grain size and leaf angle are key agronomic traits that determine final yields in rice.However,the underlying molecular mechanisms are not well understood.Here we demonstrate that the Oryza sativa Mitogen Activated Protein Kinase Kinase Kinase OsMKKK70 regulates grain size and leaf angle in rice.Overexpressing OsMKKK70 caused plants to produce longer seeds.The osmkkk62/70 double mutant and the osmkkk55/62/70 triple mutant displayed significantly smaller seeds and a more erect leaf angle compared to the wild type,indicating that OsMKKK70 functions redundantly with its homologs Os MKKK62 and Os MKKK55.Biochemical analysis demonstrated that OsMKKK70 is an active kinase and that OsMKKK70 interacts with Os MKK4 and promotes Os MAPK6 phosphorylation.In addition,the osmkkk62/70 double mutant showed reduced sensitivity to Brassinosteroids(BRs).Finally,overexpressing constitutively active Os MKK4,Os MAPK6,and Os WRKY53 can partially complement the smaller seed size,erect leaf,and BR hyposensitivity of the osmkkk62/70 double mutant.Taken together,these findings suggest that OsMKKK70 might regulate grain size and leaf angle in rice by activating Os MAPK6 and that OsMKKK70,Os MKK4,Os MAPK6,and Os WRKY53 function in a common signaling pathway that controls grain shape and leaf angle.展开更多
In Pseudomonas aeruginosa(P.aeruginosa),transcription factors(TFs)are important mediators in the genetic regulation of adaptability and pathogenicity to respond to multiple environmental stresses and host defences.The...In Pseudomonas aeruginosa(P.aeruginosa),transcription factors(TFs)are important mediators in the genetic regulation of adaptability and pathogenicity to respond to multiple environmental stresses and host defences.The P.aeruginosa genome harbours 371 putative TFs;of these,about 70 have been shown to regulate virulence-associated phenotypes by binding to the promoters of their target genes.Over the past three decades,several techniques have been applied to identify TF binding sites on the P.aeruginosa genome,and an atlas of TF binding patterns has been mapped.The virulence-associated regulons of TFs show complex crosstalk in P.aeruginosa's regulatory network.In this review,we summarise the recent literature on TF regulatory networks involved in the quorum-sensing system,biofilm formation,pyocyanin synthesis,motility,the type III secretion system,the type VI secretion system,and oxidative stress responses.We discuss future perspectives that could provide insights and targets for preventing clinical infections caused by P.aeruginosa based on the global regulatory network of transcriptional regulators.展开更多
Brassinosteroids(BRs)are plant-specific steroid hormones which regulate plant growth,development,and adaptation.Transcriptional regulation plays key roles in plant hormone signaling.A mediator can serve as a bridge be...Brassinosteroids(BRs)are plant-specific steroid hormones which regulate plant growth,development,and adaptation.Transcriptional regulation plays key roles in plant hormone signaling.A mediator can serve as a bridge between gene-specific transcription factors and the RNA polymerase machinery,functioning as an essential component in regulating the transcriptional process.However,whether a mediator is involved in BR signaling is unknown.Here,we discovered that Oryza sativa mediator subunit 25(Os MED25)is an important regulator of rice BR signaling.Phenotypic analyses showed that the Os MED25-RNAi and osmed25 mutant presented erect leaves,as observed in BR-deficient mutants.In addition,the Os MED25-RNAi and osmed25 mutant exhibited decreased BR sensitivity.Genetic analysis indicated that Os MED25-RNAi could suppress the enhanced BR signaling phenotype of Osbzr1-D.Further biochemical analysis showed that Os MED25 interacts with Os BZR1 in vivo,and Os MED25 is enriched on the promoter of Os BZR1 target genes.RNA sequencing analysis indicated that Os MED25 affects the expression of approximately 45%of Os BZR1-regulated genes and mainly functions as a corepressor of Os BZR1.Together,these findings revealed that Os MED25 regulates rice BR signaling by interacting with Os BZR1 and modulating the expression of Os BZR1 target genes,thus expanding our understanding of the roles of mediators in plant hormone signaling.展开更多
Flowering time is a fundamental factor determining the global distribution and final yield of rice(Oryza sativa).Although diverse flowering time genes have been reported in this crop,the transcriptional regulation of ...Flowering time is a fundamental factor determining the global distribution and final yield of rice(Oryza sativa).Although diverse flowering time genes have been reported in this crop,the transcriptional regulation of its key flowering genes are poorly understood.Here,we report that a basic leucine zipper transcription factor,bZIP71,functions as a flowering repressor.The overexpression of bZIP71 delays flowering,while the bzip71 mutant flowers early in both long-day and short-day conditions.A genetic analysis showed that the regulation of flowering by bZIP71 might be independent of Heading date 2(Hd2),Hd4,and Hd5.Importantly,bZIP71 directly associates with the Early heading date 1(Ehd1)promoter and represses its transcription,and genetically the function of bZIP71 is impaired in the ehd1 mutant.Moreover,bZIP71 interacts with major components of polycomb repressive complex 2(PRC2),SET domain group protein 711(SDG711),and Fertilization independent endosperm 2(FIE2),through which bZIP71 regulates the H3K27me3 level of Ehd1.Taken together,we present a transcriptional regulatory mechanism in which bZIP71 enhances the H3K27me3 level of Ehd1 and transcriptionally represses its expression,which not only offers a novel insight into a flowering pathway,but also provides a valuable putative target for the genetic engineering and breeding of elite rice cultivars.展开更多
Panicle exsertion is one of the crucial agronomic traits in rice(Oryza sativa).Shortening of panicle exsertion often leads to panicle enclosure and severely reduces seed production.Gibberellin(GA)plays important roles...Panicle exsertion is one of the crucial agronomic traits in rice(Oryza sativa).Shortening of panicle exsertion often leads to panicle enclosure and severely reduces seed production.Gibberellin(GA)plays important roles in regulating panicle exsertion.However,the underlying mechanism and the relative regulatory network remain elusive.Here,we characterized the oswrky78 mutant showing severe panicle enclosure,and found that the defect of oswrky78 is caused by decreased bioactive GA contents.Biochemical analysis demonstrates that OsWRKY78 can directly activate GA biosynthesis and indirectly suppress GA metabolism.Moreover,we found OsWRKY78 can interact with and be phosphorylated by mitogen-activated protein kinase(MAPK)kinase OsMAPK6,and this phosphorylation can enhance OsWRKY78 stability and is necessary for its biological function.Taken together,these results not only reveal the critical function of OsWRKY78,but also reveal its mechanism via mediating crosstalk between MAPK and the GA signaling pathway in regulating panicle exsertion.展开更多
基金supported by Natural Science Foundation of Heilongjiang Province(Grant No.JQ2020C003)National Natural Science Foundation of China-Heilongjiang Joint Fund(Grant No.U20A2025)+2 种基金Youth Innovation Promotion Association CAS(Grant No.2021229)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA24040102)National Natural Science Foundation of China(Grant Nos 31671653,31801017,31871591)。
文摘Grain size and leaf angle are key agronomic traits that determine final yields in rice.However,the underlying molecular mechanisms are not well understood.Here we demonstrate that the Oryza sativa Mitogen Activated Protein Kinase Kinase Kinase OsMKKK70 regulates grain size and leaf angle in rice.Overexpressing OsMKKK70 caused plants to produce longer seeds.The osmkkk62/70 double mutant and the osmkkk55/62/70 triple mutant displayed significantly smaller seeds and a more erect leaf angle compared to the wild type,indicating that OsMKKK70 functions redundantly with its homologs Os MKKK62 and Os MKKK55.Biochemical analysis demonstrated that OsMKKK70 is an active kinase and that OsMKKK70 interacts with Os MKK4 and promotes Os MAPK6 phosphorylation.In addition,the osmkkk62/70 double mutant showed reduced sensitivity to Brassinosteroids(BRs).Finally,overexpressing constitutively active Os MKK4,Os MAPK6,and Os WRKY53 can partially complement the smaller seed size,erect leaf,and BR hyposensitivity of the osmkkk62/70 double mutant.Taken together,these findings suggest that OsMKKK70 might regulate grain size and leaf angle in rice by activating Os MAPK6 and that OsMKKK70,Os MKK4,Os MAPK6,and Os WRKY53 function in a common signaling pathway that controls grain shape and leaf angle.
基金supported by Project of the Dominant Discipline in Jiangsu Province,China(No.80900246 to X.S.)General Research Fund of Hong Kong,China(No.11102720,21103018,11101619,11103221 and 11103221 to X.D.)+1 种基金National Natural Science Foundation of China(No.32272619 to X.S.,No.31870116 and 32172358 to X.D.)Tung Biomedical Sciences Centre,China(No.9609313 to X.D.).
文摘In Pseudomonas aeruginosa(P.aeruginosa),transcription factors(TFs)are important mediators in the genetic regulation of adaptability and pathogenicity to respond to multiple environmental stresses and host defences.The P.aeruginosa genome harbours 371 putative TFs;of these,about 70 have been shown to regulate virulence-associated phenotypes by binding to the promoters of their target genes.Over the past three decades,several techniques have been applied to identify TF binding sites on the P.aeruginosa genome,and an atlas of TF binding patterns has been mapped.The virulence-associated regulons of TFs show complex crosstalk in P.aeruginosa's regulatory network.In this review,we summarise the recent literature on TF regulatory networks involved in the quorum-sensing system,biofilm formation,pyocyanin synthesis,motility,the type III secretion system,the type VI secretion system,and oxidative stress responses.We discuss future perspectives that could provide insights and targets for preventing clinical infections caused by P.aeruginosa based on the global regulatory network of transcriptional regulators.
基金National Natural Science Foundation of China(31671653,31801017,31871591)National Transgenic Science and Technology Program(2018ZX0800102B)+1 种基金National Key Research and Development Program of China(2017YFD0100501)Natural Science Foundation of Heilongjiang Province(C2018064)。
文摘Brassinosteroids(BRs)are plant-specific steroid hormones which regulate plant growth,development,and adaptation.Transcriptional regulation plays key roles in plant hormone signaling.A mediator can serve as a bridge between gene-specific transcription factors and the RNA polymerase machinery,functioning as an essential component in regulating the transcriptional process.However,whether a mediator is involved in BR signaling is unknown.Here,we discovered that Oryza sativa mediator subunit 25(Os MED25)is an important regulator of rice BR signaling.Phenotypic analyses showed that the Os MED25-RNAi and osmed25 mutant presented erect leaves,as observed in BR-deficient mutants.In addition,the Os MED25-RNAi and osmed25 mutant exhibited decreased BR sensitivity.Genetic analysis indicated that Os MED25-RNAi could suppress the enhanced BR signaling phenotype of Osbzr1-D.Further biochemical analysis showed that Os MED25 interacts with Os BZR1 in vivo,and Os MED25 is enriched on the promoter of Os BZR1 target genes.RNA sequencing analysis indicated that Os MED25 affects the expression of approximately 45%of Os BZR1-regulated genes and mainly functions as a corepressor of Os BZR1.Together,these findings revealed that Os MED25 regulates rice BR signaling by interacting with Os BZR1 and modulating the expression of Os BZR1 target genes,thus expanding our understanding of the roles of mediators in plant hormone signaling.
基金supported by National Natural Science Foundation of China(Grant No.31801327)National Natural Science Foundation of China-Heilongjiang Joint Fund(Grant No.U20A2025)+1 种基金Natural Science Foundation of Heilongjiang Province(Grant No.JQ2020C003)Youth Innovation Promotion Association CAS(Grant No.2022231)。
文摘Flowering time is a fundamental factor determining the global distribution and final yield of rice(Oryza sativa).Although diverse flowering time genes have been reported in this crop,the transcriptional regulation of its key flowering genes are poorly understood.Here,we report that a basic leucine zipper transcription factor,bZIP71,functions as a flowering repressor.The overexpression of bZIP71 delays flowering,while the bzip71 mutant flowers early in both long-day and short-day conditions.A genetic analysis showed that the regulation of flowering by bZIP71 might be independent of Heading date 2(Hd2),Hd4,and Hd5.Importantly,bZIP71 directly associates with the Early heading date 1(Ehd1)promoter and represses its transcription,and genetically the function of bZIP71 is impaired in the ehd1 mutant.Moreover,bZIP71 interacts with major components of polycomb repressive complex 2(PRC2),SET domain group protein 711(SDG711),and Fertilization independent endosperm 2(FIE2),through which bZIP71 regulates the H3K27me3 level of Ehd1.Taken together,we present a transcriptional regulatory mechanism in which bZIP71 enhances the H3K27me3 level of Ehd1 and transcriptionally represses its expression,which not only offers a novel insight into a flowering pathway,but also provides a valuable putative target for the genetic engineering and breeding of elite rice cultivars.
基金supported by the National Natural Science Foundation of China(Grant No.31671653,31801017)Heilongjiang Key Research and Development Program(Grant No.2022ZX02B03)+2 种基金National Natural Science Foundation of China-Heilongjiang Joint Fund(Grant No.U23A20193)Youth Innovation Promotion Association Chinese Academy of Sciences(Grant No.2021229)Young Scientist Group Project of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(Grant No.2023QNXZ02)。
文摘Panicle exsertion is one of the crucial agronomic traits in rice(Oryza sativa).Shortening of panicle exsertion often leads to panicle enclosure and severely reduces seed production.Gibberellin(GA)plays important roles in regulating panicle exsertion.However,the underlying mechanism and the relative regulatory network remain elusive.Here,we characterized the oswrky78 mutant showing severe panicle enclosure,and found that the defect of oswrky78 is caused by decreased bioactive GA contents.Biochemical analysis demonstrates that OsWRKY78 can directly activate GA biosynthesis and indirectly suppress GA metabolism.Moreover,we found OsWRKY78 can interact with and be phosphorylated by mitogen-activated protein kinase(MAPK)kinase OsMAPK6,and this phosphorylation can enhance OsWRKY78 stability and is necessary for its biological function.Taken together,these results not only reveal the critical function of OsWRKY78,but also reveal its mechanism via mediating crosstalk between MAPK and the GA signaling pathway in regulating panicle exsertion.
