Shaping inheritance: how distinct reproductive strategies influence DNA methylation memory in plants

DNA methylation is a major epigenetic mark involved in the silencing of genes and transposable elements (TEs). DNA methylation varies significantly across the plant life cycle, but is efficiently reinforced during reproduction, ensuring stable silencing of TEs. Plants are remarkably flexible in their mode of reproduction and numerous species, including crops, can propagate asexually, skipping one or more of these critical reinforcement steps. In this review, we summarize recent advances in the characterization of DNA methylation inheritance in sexual and asexual plants. We argue that because most epigenetic reinforcement appears to occur during seed formation, methylomes of asexual seeds should resemble that of their sexual counterparts. Conversely, clonally propagated plants are expected to be hypomethylated and undergo frequent stochastic epigenetic changes. Last, we provide insights on how the use of nonmodel organisms will advance our understanding of epigenetic inheritance in plants.

Automated summary

DNA methylation is a key epigenetic mark that plays a role in gene silencing and transposable elements' (TEs) repression. It varies significantly throughout the plant life cycle, but is efficiently reinforced during reproduction to maintain stable TE silencing. Plant reproduction can occur through different modes, including asexual propagation, which bypasses critical reinforcement steps. This review summarizes recent progress in understanding DNA methylation inheritance in sexual and asexual plants. It suggests that the methylomes of asexual seeds should resemble those of sexual counterparts, whereas clonally propagated plants are expected to have hypomethylated genomes with frequent stochastic epigenetic changes. The use of nonmodel organisms holds promise for advancing our knowledge of epigenetic inheritance in plants.