DOI: 10.1093/jxb/eraf015

发表期刊：Journal of Experimental Botany

链接：https://doi.org/10.1093/jxb/eraf015

作者: Zhongfu Yang, Haidong Yan, Gang Nie, Jiajing Xiao, Jianping Wang, Guangyan Feng, Dandan Li, Linkai Huang*, Xinquan Zhang*

Abstract：Flowering, a pivotal plant life cycle event, is intricately regulated by environmental and endogenous signals via genetic and epigenetic mechanisms. Photoperiod is a crucial environmental cue that induces flowering by activating integrators through genetic and epigenetic pathways. However, the specific role of DNA methylation, a conserved epigenetic marker, in photoperiodic flowering remains unclear. This study integrated methylome, transcriptome, and gene expression analyses in orchardgrass (Dactylis glomerata) to elucidate the molecular mechanisms underlying long-day (LD) flowering. We found that LD treatment led to CHH hypermethylation, which was associated with the increased expression of RNA-dependent DNA methylation pathway components. LD-induced CHH hypermethylation in promoters correlated with up-regulated photoperiod pathway genes and down-regulated miRNAs. The suppression of DNA methylation under LD conditions delays flowering, highlighting the critical role of hypermethylation. Additionally, a novel miR1736-3p was identified as a negative regulator of FLOWERING LOCUS T (DgFT). These findings elucidate the promotion of flowering through LD-induced CHH hypermethylation and provide insights into using epigenetic techniques to control plant flowering time.

Keywords: DNA methylation, epigenetic regulation, flowering, photoperiod, RdDM, siRNA