DNA甲基化是重要的植物基因组表观遗传修饰。植物中DNA甲基化的建立与维持是由多个调控因子协同作用的结果。不同的甲基转移酶类能直接作用于不同位点胞嘧啶甲基化,其中MET1主要负责保持原初CG位点的甲基化,CMT3主要负责保持CNG位点的甲基化,并由DRM与CMT3的协同从头甲基化作用来补偿其他相关序列的甲基化。这些甲基转移酶与染色质重塑解旋酶和组蛋白修饰因子协同改变染色质的结构,行使表观遗传的功能。DNA转葡糖基酶有去甲基化活性从而减轻基因沉默。文章综述了以上植物DNA甲基化调控因子的生物学功能及其之间的相互作用和近年来的研究进展,以更好的理解DNA甲基化的建立、保持和去除的机制。
DNA methylation is an important epigenetic modification and multiple factors interact to regulate the establishment and maintenance of DNA methyaltion in plant genome. Different methylation sites require different cytosine methyltransferases, which contribute to the modification of chromatin structure and mediate epigenetics with chromatin remodeling enzymes and histone modifying factors. DNA glycosylases can remove DNA methylation and alleviate silencing. The functions and interactions of DNA methylation regulating factors, the establishment, mantainace and removement mechanisms of DNA methylations are reviewed in this paper.