Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Sapporo, Hokkaido 062-8517, Japan.
Int J Mol Sci. 2021 Apr 16;22(8):4125. doi: 10.3390/ijms22084125.
DNA methylation maintains genome stability and regulates gene expression in plants. RNA-directed DNA methylation (RdDM) is critical for appropriate methylation. However, no efficient tools are available for the investigation of the functions of specific DNA methylation. In this study, the cucumber mosaic virus vector was used for targeted DNA methylation. Methylation was rapidly induced but gradually decreased from the 3' end of the target endogenous sequence in , suggesting a mechanism to protect against the ectopic introduction of DNA methylation. Increasing 24-nt siRNAs blocked this reduction in methylation by down-regulating and . RdDM relies on the sequence identity between RNA and genomic DNA; however, this identity does not appear to be the sole determinant for efficient DNA methylation. The current findings provide new insight into the regulation of DNA methylation and promote additional effort to develop efficient targeted DNA methylation in plants.
DNA 甲基化维持基因组稳定性并调节植物中的基因表达。RNA 指导的 DNA 甲基化（RdDM）对于适当的甲基化至关重要。然而，目前还没有有效的工具可用于研究特定 DNA 甲基化的功能。在本研究中，使用黄瓜花叶病毒载体进行靶向 DNA 甲基化。在 中，从靶内源序列的 3' 端迅速诱导甲基化，但逐渐减少，表明存在一种机制来防止外源 DNA 甲基化的引入。增加 24-nt siRNAs 通过下调 和 来阻止这种甲基化的减少。RdDM 依赖于 RNA 和基因组 DNA 之间的序列同一性；然而，这种同一性似乎不是有效 DNA 甲基化的唯一决定因素。目前的研究结果为 DNA 甲基化的调控提供了新的见解，并促进了进一步努力在植物中开发有效的靶向 DNA 甲基化。
