Abstract:

In plant genome, gene expression often depends on transcriptional regulation and chromatin structure conversion. RNA polymerase Ⅳ and RNA polymerase Ⅴ, two RNA polymerase II-related RNA polymerases, are specific in plant. Their transcriptional production includes long non-coding RNA and small interfering RNA, broadly involved in methylation or demethylation of cytosine and spreading of methylation on plant genome. Recently, research showed that RNA-mediated and chromatin-based gene silence are involved in plant growth and development, stress response and epigenetic polymorphism. It is exerting  evident influences on plant phenotypic diversity, physiological adaptability and evolutional change.

Key words: epigenomic, RNA polymerase, small interfering RNA (siRNA), RNA-directed DNA methylation (RdDM), DNA methylation

摘要：

植物基因组对基因的表达调控不仅表现在转录水平上,也表现在染色质结构的变化上。在植物中存在着特有的RNA 聚合酶Ⅳ (RNA Pol Ⅳ) 和 RNA聚合酶Ⅴ (RNA Pol Ⅴ),它们与RNA 聚合酶Ⅱ(RNA Pol Ⅱ)相似。RNA Pol Ⅳ和RNA Pol Ⅴ的转录产物包括参与表观遗传调控的长链非编码RNA (lncRNAs)和干扰小RNA (siRNAs)。这类非编码RNA广泛地参与了基因组上发生的胞嘧啶甲基化,去甲基化以及甲基化扩散。近年来,研究已经发现RNA介导的染色质水平的基因沉默涉及植物的生长发育、胁迫应答、表观遗传多态性,并对植物的表型多样化、生理适应性以及植物进化具有显著影响。

关键词: 表观遗传;RNA聚合酶;干扰小RNA (siRNA);RNA介导的DNA甲基化(RdDM);DNA甲基化