DNA甲基化在植物与双生病毒互作中的作用

Molecular Mechanisms of DNA Methylation in Plant-Geminivirus Interaction

DNA甲基化是一种重要的表观遗传修饰,在维持基因组稳定、调控基因表达、转座子沉默以及植物抗逆等过程中具有重要作用.基因组为单链环状DNA的双生病毒复制过程中形成的双链DNA与组蛋白结合形成微染色体,可诱导并成为DNA甲基化的靶标.而相应地,双生病毒在与植物长期斗争中,进化出多种不同类型的抑制子并且通过不同的策略来抑制DNA甲基化以逃脱植物的防御反应.本文将结合植物与病毒互作中的研究重点,简述DNA甲基化在植物抗双生病毒方面的研究进展,并围绕双生病毒编码的蛋白抑制DNA甲基化的机制进行综述,以更好地理解植物中DNA甲基化介导的表观遗传调控在植物与双生病毒互作中的作用.

DNA methylation is a fundamental epigenetic mark that has been implicated in maintaining genome stability, regulating gene expression, controlling transposon silencing and defending against pathogen invasion. It also serves as a potent defense against single-stranded DNA containing geminiviruses. During this process, geminiviral minichromosomes are subject to DNA methylation, leading to transcriptional gene silencing. As a counterdefense, geminiviruses have developed diverse strategies to interfere with the methyl cycles or target methyltransferase component of the RNA-directed DNA methylation pathway of their host plants through evolution. This review describes our current knowledge of the antiviral role of DNA methylation in geminivirus infection. Research advances on the epigenetic arms race between plant and geminivirus will help understand the molecular basis of plant-geminivirus interaction.