RNA沉默——植物基因组免疫的安全防线

RNA silencing, the fundamental security strategy of genomic immunity: a review

摘要:

在植物中，起始于双链RNA的长度为21~24个核苷酸的小RNA，能够诱发两种形式的表观遗传学基因沉默。转录后基因沉默 (Post-transcriptional gene silencing，PTGS)，可以介导细胞质中同源mRNA的降解；转录基因沉默 (Transcriptional gene silencing，TGS)，则主要通过小RNA介导同源启动子区的DNA甲基化，从而抑制基因转录。文中针对PTGS和TGS通路的区别与联系、沉默传递研究的现状及内源与外源基因沉默的异同点等问题进行探讨。

Abstract:

The 21-24 nucleotides small RNA that generated from double strands RNA can trigger two types of epigenetic gene silencing in plants. One is Post-Transcriptional Gene Silencing (PTGS), characterized by cleavage of homologous mRNA in cytoplasm. Transcriptional Gene Silencing (TGS) is another one, in which transcription inhibition is obtained through small RNA-directed DNA methylation of homologous promoter region. Here we summarized the relationship and differences between PTGS and TGS, the current achievement in the study of RNA silencing spreading, as well as the discrepancy of exogenous and endogenous gene silencing, and discussed the underlying reasons in the end.