An H3K27me3 demethylase-HSFA2 regulatory loop orchestrates transgenerational thermomemory in Arabidopsis

• 来源期刊: 细胞研究（英文版）
• 年，卷（期）: 2019,（5）
• 页码范围: 379-390
• 页数: 12页
• 语种: 英文

摘要

Global warming has profound effects on plant growth and fitness.Plants have evolved sophisticated epigenetic machinery to respond quickly to heat,and exhibit transgenerational memory of the heat-induced release of post-transcriptional gene silencing (PTGS).However,how thermomemory is transmitted to progeny and the physiological relevance are elusive.Here we show that heat-induced HEAT SHOCK TRANSCRIPTION FACTOR A2 (HSFA2) directly activates the H3K27me3 demethylase RELATIVE OF EARLY FLOWERING 6 (REF6),which in turn derepresses HSFA2.REF6 and HSFA2 establish a heritable feedback loop,and activate an E3 ubiquitin ligase,SUPPRESSOR OF GENE SILENCING 3 (SGS3)-INTERACTING PROTEIN 1 (SGIP1).SGIP1-mediated SGS3 degradation leads to inhibited biosynthesis of trans-acting siRNA (tasiRNA).The REFG-HSFA2 loop and reduced tasiRNA converge to release HEAT-INDUCED TAS1 TARGET 5 (HTT5),which drives early flowering but attenuates immunity.Thus,heat induces transmitted phenotypes via a coordinated epigenetic network involving histone demethylases,transcription factors,and tasiRNAs,ensuring reproductive success and transgenerational stress adaptation.