Leaf senescence is driven by the expression of senescence-associated genes(SAGs).Development-specific genes often undergo DNA demethylation in their promoter and other regions,which regulates gene expression.Whether a...Leaf senescence is driven by the expression of senescence-associated genes(SAGs).Development-specific genes often undergo DNA demethylation in their promoter and other regions,which regulates gene expression.Whether and how DNA demethylation regulates the expression of SAGs and thus leaf senescence remain elusive.Whole-genome bisulfite sequencing(WGBS)analyses of wild-type(WT)and demeter-like 3(dml3)Arabidopsis leaves at three developmental stages revealed hypermethylation during leaf senescence in dml3 compared with WT,and 20556 differentially methylated regions(DMRs)were identified by comparing the methylomes of dml3 and WT in the CG,CHG,and CHH contexts.Furthermore,we identified that 335 DMR-associated genes(DMGs),such as NAC016 and SEN1,are upregulated during leaf senescence,and found an inverse correlation between the DNA methylation levels(especially in the promoter regions)and the transcript abundances of the related SAGs in WT.In contrast,in dml3 the promoters of SAGs were hypermethylated and their transcript levels were remarkably reduced,and leaf senescence was significantly delayed.Collectively,our study unraveled a novel epigenetic regulatory mechanism underlying leaf senescence in which DML3 is expressed at the onset of and during senescence to demethylate promoter,gene body or 3'UTR regions to activate a set of SAGs.展开更多
Increasingly warming temperature impacts on all aspects of growth and development in plants.Flower development is a complex process that is very sensitive to ambient temperature,and warming temperatures often lead to ...Increasingly warming temperature impacts on all aspects of growth and development in plants.Flower development is a complex process that is very sensitive to ambient temperature,and warming temperatures often lead to abnor-mal flower development and remarkably reduce the quality and yield of inflorescent vegetables and many other crops,which can be exemplified by Brassica oleracea cv.Green Harmony F1,a broccoli cultivar,whose floral develop-ment is ceased at inflorescence meristem(at 28℃)or floral primordium stage(at 22℃),forming a cauliflower-like curd(28℃)or intermediate curd(22℃)instead of normal broccoli head at 16℃.However,the underlying molecular regulatory mechanisms are not well understood.Here we report that warming temperature(28℃ or 22℃)induced hypermethylation of the genome,especially the promoter regions of such sets of genes as ribosome biogenesis-related and others,leading to the suppression of the apex-highly-expressed distinctive genes,subsequently resulting in the abnormal floral development,as revealed by methylome and transcriptome co-profiling.The regulation of warming-induced abnormal floral development in broccoli was further verified by the fact that the DNA methylation inhibitor 5-azacytidine(5-azaC)released the expression of genes from the warming temperature-induced suppres-sion,and restored the broccoli development to normalcy at warming temperature.The research provided new approaches to breeding broccoli and other crops for growing in wider or warmer temperature zones.展开更多
基金This work was supported by the National Key Research and Development Program of China(grant no.2019YFD1000300,to L.Chen)by Cornell University 1843351(to S.G.).
文摘Leaf senescence is driven by the expression of senescence-associated genes(SAGs).Development-specific genes often undergo DNA demethylation in their promoter and other regions,which regulates gene expression.Whether and how DNA demethylation regulates the expression of SAGs and thus leaf senescence remain elusive.Whole-genome bisulfite sequencing(WGBS)analyses of wild-type(WT)and demeter-like 3(dml3)Arabidopsis leaves at three developmental stages revealed hypermethylation during leaf senescence in dml3 compared with WT,and 20556 differentially methylated regions(DMRs)were identified by comparing the methylomes of dml3 and WT in the CG,CHG,and CHH contexts.Furthermore,we identified that 335 DMR-associated genes(DMGs),such as NAC016 and SEN1,are upregulated during leaf senescence,and found an inverse correlation between the DNA methylation levels(especially in the promoter regions)and the transcript abundances of the related SAGs in WT.In contrast,in dml3 the promoters of SAGs were hypermethylated and their transcript levels were remarkably reduced,and leaf senescence was significantly delayed.Collectively,our study unraveled a novel epigenetic regulatory mechanism underlying leaf senescence in which DML3 is expressed at the onset of and during senescence to demethylate promoter,gene body or 3'UTR regions to activate a set of SAGs.
基金Open access funding provided by Shanghai Jiao Tong University.This work was supported by the National Natural Science Foundation of China(Grant no.32172561 to L.P.C.)the China Postdoctoral Science Foundation(Grant no.2021 M702878 to L.Y.)the USDA NIFA(NYC-184404 to S.S.G).
文摘Increasingly warming temperature impacts on all aspects of growth and development in plants.Flower development is a complex process that is very sensitive to ambient temperature,and warming temperatures often lead to abnor-mal flower development and remarkably reduce the quality and yield of inflorescent vegetables and many other crops,which can be exemplified by Brassica oleracea cv.Green Harmony F1,a broccoli cultivar,whose floral develop-ment is ceased at inflorescence meristem(at 28℃)or floral primordium stage(at 22℃),forming a cauliflower-like curd(28℃)or intermediate curd(22℃)instead of normal broccoli head at 16℃.However,the underlying molecular regulatory mechanisms are not well understood.Here we report that warming temperature(28℃ or 22℃)induced hypermethylation of the genome,especially the promoter regions of such sets of genes as ribosome biogenesis-related and others,leading to the suppression of the apex-highly-expressed distinctive genes,subsequently resulting in the abnormal floral development,as revealed by methylome and transcriptome co-profiling.The regulation of warming-induced abnormal floral development in broccoli was further verified by the fact that the DNA methylation inhibitor 5-azacytidine(5-azaC)released the expression of genes from the warming temperature-induced suppres-sion,and restored the broccoli development to normalcy at warming temperature.The research provided new approaches to breeding broccoli and other crops for growing in wider or warmer temperature zones.
