Transgenerational Epigenetic Inheritance of Diverse Chromatin States in Plants
Transgenerational epigenetic inheritance (TEI) enables the plant to transmit adaptive chromatin states across generations. However, the mechanism by which these states are maintained and stabilized during TEI remains unclear. Reinforcement loops mediated by reader-writer feedback are thought to ensure the stability of epigenetic marks, but the contribution of chromatin remodelers is poorly understood. Here we investigated the transgenerational stability of repressive marks (H3K27me3, DNA methylation) alongside the active mark H3K4me3 using reciprocal crosses of Arabidopsis thaliana ecotypes Col (Col-0) and C24. We found that all three marks transmitted across generations but show diverse transmission patterns depending on their reinforcement mechanism. Repressive marks propagated, stably coordinated by chromatin remodeler DDM1, which maintains chromatin accessibility integrates reader writer feedback and facilitates siRNA guided DNA methylation. Together our findings support a mechanistic model in which chromatin remodeling contributes to TEI by regulating nucleosome spacing and histone variations, thereby modulating the catalytic and binding activity of the readers and writers. This study provides mechanistic insight into how chromatin remodeler shapes TEI in plants.