Histone H2B ubiquitination(H2Bub)is positively linked to transcriptional activation,but the genetic programs affected by H2Bub to enhance drought tolerance remain largely unknown.Here,we show that OsbZIP27 interacts d...Histone H2B ubiquitination(H2Bub)is positively linked to transcriptional activation,but the genetic programs affected by H2Bub to enhance drought tolerance remain largely unknown.Here,we show that OsbZIP27 interacts directly with OsHUB1/2 to regulate drought tolerance in rice by binding to the promoters of OsHAK1 and OsGLN1 to achieve H2Bub and transcriptional activation.Consistently,mutations in OsbZIP27 reduce transcription of OsHAK1 and OsGLN1,resulting in increased sensitivity to drought stress.Moreover,loss of OsHUB1 and OsHUB2 function causes hypersensitivity to drought stress,whereas OsHUB2 overexpression enhances drought tolerance.Together,our results indicate that OsbZIP27 coordinates with OsHUB1/2 to enhance rice drought tolerance by increasing H2Bub and expression of OsHAK1 and OsGLN1.展开更多
Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1...Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1 is crucially involved in abscisic acid (ABA) signaling and drought response in rice. We found that rice HISTONE MONOUBIQUITINATION2 (OsHUB2), an E3 ligase for H2Bub1, in teracted with OsbZIP46, a key transcription factor regulating ABA signaling and drought response in rice. Genetic analyses suggest that OsHUB2, upregulated by drought and ABA, positively modulates ABA sensitivity and drought resistance. The H2Bub1 levels were in creased in the target genes of OsbZIP46 under the drought stress and ABA treat- merits, which were positively correlated with their increased expression levels. Interestingly, MODD, a reported suppressor of ABA signaling and drought resistance by mediating OsbZIP46 deactivation and degradation, could reduce the H2Bub1 levels in the target genes of OsbZIP46 by recruiting a putative deubiquitinase OsOTLD1 . Suppression of OsOTLD1in vivo resulted in increased H2Bub1 levels and expression of OsbZIP46 target genes. Collectively, these fin dings established an elaborate mecha nism of histone monoubiquitination in the fine-turning of ABA signaling and drought response by balancing H2Bub1 deposition and removal.展开更多
Plant height is an important agronomic trait for lodging resistance and yield.Here,we report a new plantheight-related gene,OsUBR7 in rice(Oryza sativa L.);knockout of OsUBR7 caused fewer cells in internodes,resulting...Plant height is an important agronomic trait for lodging resistance and yield.Here,we report a new plantheight-related gene,OsUBR7 in rice(Oryza sativa L.);knockout of OsUBR7 caused fewer cells in internodes,resulting in a semi-dwarf phenotype.OsUBR7 encodes a putative E3 ligase containing a plant homeodomain finger and a ubiquitin protein ligase E3 component N-recognin 7(UBR7)domain.OsUBR7 interacts with histones and monoubiquitinates H2B(H2Bub1)at lysine148 in coordination with the E2 conjugase OsUBC18.OsUBR7 mediates H2Bub1 at a number of chromatin loci for the normal expression of target genes,including cell-cycle-related and pleiotropic genes,consistent with the observation that cell-cycle progression was suppressed in the osubr7 mutant owing to reductions in H2Bub1 and expression levels at these loci.The genetic divergence of OsUBR7 alleles among japonica and indica cultivars affects their transcriptional activity,and these alleles may have undergone selection during rice domestication.Overall,our results reveal a novel mechanism that mediates H2Bub1 in plants,and UBR7 orthologs could be utilized as an untapped epigenetic resource for crop improvement.展开更多
Histone ubiquitination plays a critical role in the regulation of transcription,and histone H2B monoubiquitination(H2Bub1)is mainly associated with transcriptional activation.Recent studies in yeast,humans,and Arabido...Histone ubiquitination plays a critical role in the regulation of transcription,and histone H2B monoubiquitination(H2Bub1)is mainly associated with transcriptional activation.Recent studies in yeast,humans,and Arabidopsis have revealed the conservation of chromatin modification via H2Bub1 during evolution.Rad6-Bre1 and their homologs are responsible for H2B monoubiquitination in diverse eukaryotic organisms,and the PAF complex is required for H2Bub1 to proceed.H2Bub1 is involved in many developmental processes in yeast,humans,and Arabidopsis,and it activates gene transcription by regulating the H3K4 methylation state.Notably,the level of H3K4 methylation is entirely dependent on H2Bub1 in yeast and humans,whereas the H3K4 methylation level of only a small number of genes in Arabidopsis is dependent on H2Bub1.In this review,we summarize the enzymes involved in H2B monoubiquitination and deubiquitination,and discuss the biologic functions of H2Bub1 in different organisms.In addition,we focus on recent advances in our understanding of the molecular mechanisms that enable H2Bub1 to perform its function.展开更多
Posttranslational modifications(PTMs),such as ubiquitination and phosphorylation,regulate diverse cellular processes.Whereas individual contributions of PTMs to leaf senescence have been well documented,their crosstal...Posttranslational modifications(PTMs),such as ubiquitination and phosphorylation,regulate diverse cellular processes.Whereas individual contributions of PTMs to leaf senescence have been well documented,their crosstalk remains largely unexplored.In this study,we identified Arabidopsis To′xicos en Levadura 72(ATL72),a RING-type E3 ligase,as a positive regulator of leaf senescence in Arabidopsis.ATL72 targets senescence-suppressed protein phosphatase(SSPP),which negatively regulates leaf senescence by dephosphorylating Arabidopsis thaliana(A.thaliana)senescence-associated receptor-like kinase(AtSARK).Expression patterns of ATL72,SSPP,and AtSARK overlap during senescence initiation in leaf development,suggesting that these proteins coordinate to regulate senescence.Our results show that the effect of ATL72 on leaf senescence is dependent on AtSARK.Furthermore,ATL72 monoubiquitinates SSPP;this interaction does not affect the stability of SSPP but significantly reduces its ability to dephosphorylate AtSARK.The SSPPinduced delay in leaf senescence can be effectively rescued by ATL72.We also identified the monoubiquitination sites on SSPP.Collectively,these findings provide critical insights into how complex networks of PTM crosstalk orchestrate the initiation and progression of leaf senescence.展开更多
From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which Pe...From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which PeG machinery mediates gene repression is still largely unknown in plants. Compared to animals, few PcG proteins have been identi- fied in plants, not only because just some of these proteins are clearly conserved to their animal counterparts, but also because some PcG functions are carried out by plant-specific proteins, most of them as yet uncharacterized. For a long time, the apparent lack of Polycomb Repressive Complex （PRC）I components in plants was interpreted according to the idea that plants, as sessile organisms, do not need a long-term repression, as they must be able to respond rapidly to environmental signals; however, some PRC1 components have been recently identified, indicating that this may not be the case. Furthermore, new data regarding the recruitment of PcG complexes and maintenance of PcG repression in plants have revealed important differences to what has been reported so far. This review highlights recent progress in plant PcG function, focusing on the role of the putative PRC1 components.展开更多
基金supported by the Open Research Fund Program of Anhui Province Key Laboratory of Rice Genetics and Breeding(SDKF-2023-02)the Postdoctoral Research Program of Anhui Province(2022B603)+5 种基金the Key Research and Development Projects in Anhui Province(2023n06020035)the National Natural Science Foundation of China(32230017,U19A2021,and 32321001)the Natural Science Foundation of Anhui province(2408085MC083)the Global Select Project(DJK-LX-2022007)of the Institute of Health and Medicinethe Hefei Comprehensive National Science Center,the Fundamental Research Funds for the Central Universities(WK9100000047)the Anhui Academy of Agricultural Sciences Young Talent Program(QNYC-201902).
文摘Histone H2B ubiquitination(H2Bub)is positively linked to transcriptional activation,but the genetic programs affected by H2Bub to enhance drought tolerance remain largely unknown.Here,we show that OsbZIP27 interacts directly with OsHUB1/2 to regulate drought tolerance in rice by binding to the promoters of OsHAK1 and OsGLN1 to achieve H2Bub and transcriptional activation.Consistently,mutations in OsbZIP27 reduce transcription of OsHAK1 and OsGLN1,resulting in increased sensitivity to drought stress.Moreover,loss of OsHUB1 and OsHUB2 function causes hypersensitivity to drought stress,whereas OsHUB2 overexpression enhances drought tolerance.Together,our results indicate that OsbZIP27 coordinates with OsHUB1/2 to enhance rice drought tolerance by increasing H2Bub and expression of OsHAK1 and OsGLN1.
文摘Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1 is crucially involved in abscisic acid (ABA) signaling and drought response in rice. We found that rice HISTONE MONOUBIQUITINATION2 (OsHUB2), an E3 ligase for H2Bub1, in teracted with OsbZIP46, a key transcription factor regulating ABA signaling and drought response in rice. Genetic analyses suggest that OsHUB2, upregulated by drought and ABA, positively modulates ABA sensitivity and drought resistance. The H2Bub1 levels were in creased in the target genes of OsbZIP46 under the drought stress and ABA treat- merits, which were positively correlated with their increased expression levels. Interestingly, MODD, a reported suppressor of ABA signaling and drought resistance by mediating OsbZIP46 deactivation and degradation, could reduce the H2Bub1 levels in the target genes of OsbZIP46 by recruiting a putative deubiquitinase OsOTLD1 . Suppression of OsOTLD1in vivo resulted in increased H2Bub1 levels and expression of OsbZIP46 target genes. Collectively, these fin dings established an elaborate mecha nism of histone monoubiquitination in the fine-turning of ABA signaling and drought response by balancing H2Bub1 deposition and removal.
基金supported by the Major Program of Guangdong Basic and Applied Basic Research(2019B030302006)the National Natural Science Foundation of China(31921004,31871533,and 31760300)+1 种基金the Laboratory of Lingnan Modern Agriculture Project(NT2021002)the Guangdong Basic and Applied Basic Research Foundation(2019A1515010230).
文摘Plant height is an important agronomic trait for lodging resistance and yield.Here,we report a new plantheight-related gene,OsUBR7 in rice(Oryza sativa L.);knockout of OsUBR7 caused fewer cells in internodes,resulting in a semi-dwarf phenotype.OsUBR7 encodes a putative E3 ligase containing a plant homeodomain finger and a ubiquitin protein ligase E3 component N-recognin 7(UBR7)domain.OsUBR7 interacts with histones and monoubiquitinates H2B(H2Bub1)at lysine148 in coordination with the E2 conjugase OsUBC18.OsUBR7 mediates H2Bub1 at a number of chromatin loci for the normal expression of target genes,including cell-cycle-related and pleiotropic genes,consistent with the observation that cell-cycle progression was suppressed in the osubr7 mutant owing to reductions in H2Bub1 and expression levels at these loci.The genetic divergence of OsUBR7 alleles among japonica and indica cultivars affects their transcriptional activity,and these alleles may have undergone selection during rice domestication.Overall,our results reveal a novel mechanism that mediates H2Bub1 in plants,and UBR7 orthologs could be utilized as an untapped epigenetic resource for crop improvement.
基金supported by grants from China MOST 863 project(L.M.)Hebei Province Key Laboratory Program(L.M.)National Science Foundation of China(Y.C.).
文摘Histone ubiquitination plays a critical role in the regulation of transcription,and histone H2B monoubiquitination(H2Bub1)is mainly associated with transcriptional activation.Recent studies in yeast,humans,and Arabidopsis have revealed the conservation of chromatin modification via H2Bub1 during evolution.Rad6-Bre1 and their homologs are responsible for H2B monoubiquitination in diverse eukaryotic organisms,and the PAF complex is required for H2Bub1 to proceed.H2Bub1 is involved in many developmental processes in yeast,humans,and Arabidopsis,and it activates gene transcription by regulating the H3K4 methylation state.Notably,the level of H3K4 methylation is entirely dependent on H2Bub1 in yeast and humans,whereas the H3K4 methylation level of only a small number of genes in Arabidopsis is dependent on H2Bub1.In this review,we summarize the enzymes involved in H2B monoubiquitination and deubiquitination,and discuss the biologic functions of H2Bub1 in different organisms.In addition,we focus on recent advances in our understanding of the molecular mechanisms that enable H2Bub1 to perform its function.
基金supported by the National Natural Science Foundation of China(grant numbers 32270359 and 32070317).
文摘Posttranslational modifications(PTMs),such as ubiquitination and phosphorylation,regulate diverse cellular processes.Whereas individual contributions of PTMs to leaf senescence have been well documented,their crosstalk remains largely unexplored.In this study,we identified Arabidopsis To′xicos en Levadura 72(ATL72),a RING-type E3 ligase,as a positive regulator of leaf senescence in Arabidopsis.ATL72 targets senescence-suppressed protein phosphatase(SSPP),which negatively regulates leaf senescence by dephosphorylating Arabidopsis thaliana(A.thaliana)senescence-associated receptor-like kinase(AtSARK).Expression patterns of ATL72,SSPP,and AtSARK overlap during senescence initiation in leaf development,suggesting that these proteins coordinate to regulate senescence.Our results show that the effect of ATL72 on leaf senescence is dependent on AtSARK.Furthermore,ATL72 monoubiquitinates SSPP;this interaction does not affect the stability of SSPP but significantly reduces its ability to dephosphorylate AtSARK.The SSPPinduced delay in leaf senescence can be effectively rescued by ATL72.We also identified the monoubiquitination sites on SSPP.Collectively,these findings provide critical insights into how complex networks of PTM crosstalk orchestrate the initiation and progression of leaf senescence.
文摘From mammals to plants, the Polycomb Group （PcG） machinery plays a crucial role in maintaining the repres- sion of genes that are not required in a specific differentiation status. However, the mechanism by which PeG machinery mediates gene repression is still largely unknown in plants. Compared to animals, few PcG proteins have been identi- fied in plants, not only because just some of these proteins are clearly conserved to their animal counterparts, but also because some PcG functions are carried out by plant-specific proteins, most of them as yet uncharacterized. For a long time, the apparent lack of Polycomb Repressive Complex （PRC）I components in plants was interpreted according to the idea that plants, as sessile organisms, do not need a long-term repression, as they must be able to respond rapidly to environmental signals; however, some PRC1 components have been recently identified, indicating that this may not be the case. Furthermore, new data regarding the recruitment of PcG complexes and maintenance of PcG repression in plants have revealed important differences to what has been reported so far. This review highlights recent progress in plant PcG function, focusing on the role of the putative PRC1 components.
