DDM1 Shapes Transgenerational Epigenetic Inheritance of Diverse Chromatin States

Transgenerational epigenetic inheritance (TEI) enables plants to transmit adaptive chromatin states across generations. However, the mechanisms by which these states are maintained and stabilised during TEI remain unclear. Here, we investigate the TEI of repressive marks (H3K27me3 and DNA methylation) together with the active mark H3K4me3, which are associated with distinct reinforcement mechanisms, using reciprocal crosses of Arabidopsis ecotypes Col-0 and C24. We show that all three marks undergo TEI but exhibit distinct inheritance patterns depending on their reinforcement mechanisms. These inheritance patterns are modulated by DDM1, which coordinates the propagation of repressive chromatin states. Our results indicate that chromatin remodelling, through its effects on nucleosome organisation and histone variant dynamics, plays a key role in shaping TEI via chromatin context in plants.