Departments of Biology and Plant Science, The Pennsylvania State University, University Park, PA, USA.
Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, USA.
Nat Commun. 2020 May 5;11(1):2214. doi: 10.1038/s41467-020-16036-8.
MSH1 is a plant-specific protein. RNAi suppression of MSH1 results in phenotype variability for developmental and stress response pathways. Segregation of the RNAi transgene produces non-genetic msh1 'memory' with multi-generational inheritance. First-generation memory versus non-memory comparison, and six-generation inheritance studies, identifies gene-associated, heritable methylation repatterning. Genome-wide methylome analysis integrated with RNAseq and network-based enrichment studies identifies altered circadian clock networks, and phytohormone and stress response pathways that intersect with circadian control. A total of 373 differentially methylated loci comprising these networks are sufficient to discriminate memory from nonmemory full sibs. Methylation inhibitor 5-azacytidine diminishes the differences between memory and wild type for growth, gene expression and methylation patterning. The msh1 reprogramming is dependent on functional HISTONE DEACETYLASE 6 and methyltransferase MET1, and transition to memory requires the RNA-directed DNA methylation pathway. This system of phenotypic plasticity may serve as a potent model for defining accelerated plant adaptation during environmental change.
MSH1 是一种植物特异性蛋白。MSH1 的 RNAi 抑制导致发育和应激反应途径的表型变异。RNAi 转基因的分离产生具有多代遗传的非遗传 msh1“记忆”。第一代记忆与非记忆的比较，以及六代遗传研究，确定了与基因相关的、可遗传的甲基化重新模式化。与 RNAseq 和基于网络的富集研究相结合的全基因组甲基组分析鉴定出改变的生物钟网络，以及与生物钟控制相交的植物激素和应激反应途径。这些网络包含的 373 个差异甲基化基因座足以区分记忆和非记忆全同胞。甲基化抑制剂 5-氮杂胞苷可减少记忆和野生型之间在生长、基因表达和甲基化模式方面的差异。msh1 重编程依赖于功能组蛋白去乙酰化酶 6 和甲基转移酶 MET1，并且向记忆的转变需要 RNA 指导的 DNA 甲基化途径。这种表型可塑性系统可能成为定义环境变化期间植物加速适应的有力模型。
