Regulation of Leaf Longevity by DML3-Mediated DNA Demethylation

作者：Lu Yuan; Dan Wang; Liwen Cao; Ningning Yu; Ke Liu; Yongfeng Guo; Susheng Gan; Liping Chen

来源：Molecular Plant, 2020.

DOI：10.1016/j.molp.2020.06.006

• Leaf senescence
• DNA methylation
• DNA demethylase
• Epigenetics
• Whole genome bisulfite sequencing
• Arabidopsis thaliana

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 to regulate gene expression. Whether and how DNA demethylation regulates SAG s, thus leaf senescence, remain elusive. Whole genome bisulfite sequencing (WGBS) analyses of wild type (WT) and demeter-like 3 ( dml3 ) in Arabidopsis leaves at three developmental stages revealed hypermethylation during leaf senescence in dml3 compared with WT, and 20,556 differentially methylated regions (DMRs) were identified by comparing the methylomes of dml3 and WT in CG, CHG, CHH contexts. Furthermore, 335 DMR-associated genes (DMGs) such as NAC016, SEN1 were up-regulated during leaf senescence, and there was an inverse correlation between the DNA methylation levels (especially in the promoter regions) and the transcript abundance of the related SAGs in WT. In contrast, the promoters were hypermethylated and the transcript levels of the genes were remarkably reduced, and leaf senescence was significantly delayed in dml3. Our research 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 SAG s.

• 单位
  1; 中国农业科学院