Institute of Plant Biology, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Yi Chuan. 2022 Jul 20;44(7):567-580. doi: 10.16288/j.yczz.22-063.
DNA methylation is a type of stable epigenetic modifications that plays crucial roles in regulating gene expression, silencing transposons and maintaining genome stability. In plants, the de novo DNA methylation is established via a pathway termed as RNA-directed DNA methylation (RdDM). The plant-specific DNA-dependent RNA polymerase IV (Pol IV) as the core protein in RdDM pathway produces non-coding RNAs that direct the establishment of DNA methylation, regulates gene expression and controls plant development. Pol IV function is regulated by several proteins including SHH1, which recognizes H3K9 methylation and guides Pol IV to genome specific sites, the chromatin remodeling factor CLSY family that is involved in assisting Pol IV chromatin association and RDR2 that converts Pol IV produced single-stranded RNA into double-stranded RNA. In this review, we summarize the latest progress on Pol IV and its co-regulators, and focus on their functions in shaping epigenome and development in plants, which might provide implications for studying of DNA methylation and crop breeding.
DNA 甲基化是一种稳定的表观遗传修饰，在调节基因表达、沉默转座子和维持基因组稳定性方面发挥着关键作用。在植物中，从头 DNA 甲基化是通过一种称为 RNA 指导的 DNA 甲基化（RdDM）的途径建立的。植物特异性 DNA 依赖性 RNA 聚合酶 IV（Pol IV）作为 RdDM 途径的核心蛋白，产生指导 DNA 甲基化建立、调节基因表达和控制植物发育的非编码 RNA。Pol IV 的功能受到包括 SHH1 在内的几种蛋白质的调节，SHH1 识别 H3K9 甲基化并指导 Pol IV 到基因组特定位置，染色质重塑因子 CLSY 家族参与协助 Pol IV 染色质结合，以及 RDR2 将 Pol IV 产生的单链 RNA 转化为双链 RNA。在这篇综述中，我们总结了 Pol IV 及其共调节因子的最新进展，并重点介绍了它们在植物表观基因组和发育中的功能，这可能为研究 DNA 甲基化和作物育种提供启示。
