真核生物基因表达受到染色质结构的调控,组蛋白与DNA的共价修饰构成表观遗传标签,并在植物胁迫应答如防御病原菌侵染过程中起重要作用。病原菌侵染可引起基因组整体DNA甲基化模式变化及胁迫应答基因的位点特异性去甲基化,导致植物抗性基因表达上调或下调,并进一步调控植物对病原菌的胁迫应答;组蛋白去乙酰化酶HDAC通过茉莉酸途径增强植物对病原菌的胁迫应答;此外,染色质重塑复合物Swr1复合体通过识别DNA基元和组蛋白乙酰化修饰状态靶向基因启动子,负调控SA敏感基因。该文从DNA甲基化、组蛋白乙酰化、甲基化修饰,染色质重塑等方面着重阐述植物与病原菌互作过程中发生的主要事件的分子基础及其研究进展。
The gene expression in eukaryotic is regulated by chromatin structure.Epigenetic markers(like DNA methylation and histone modification) play an important role in the defense responses of plant.For example,plant DNA methylation patterns can be altered by pathogen infection,and pathogen-induced locus-specific demethylation can influence the expression of defense genes.Histone deacetylases(HDACs) promote defense responses against pathogens depended on jasmonic acid(JA) pathway.Furthermore,the chromatin remodeling complexes Swr1 may be targeted to gene promoters by the recognition of histone acetylation patterns and DNA motifs,which inhibited the expression of salicylic acid(SA)-sensitive genes.In this review,we focused on the underlying mechanisms of plant-pathogen interaction and the latest advances of epigenetics,such as DNA methylation,histone acetylation,histone methylation and chromatin remodeling.