Strawberry methylome dynamics

In plants, environmental stresses can induce a wide range of phenotypic changes by acting on epigenetic configurations, e.g., at the level of DNA methylation. It has been shown that DNA methylation is one of the few heritable epigenetic marks and is important to keep silence transposable elements (TEs). Although DNA methylation is an essential epigenetic mechanism, fundamental aspects of its contribution to stress response mechanisms remain obscure. In this study, we use whole-genome methylome sequencing (WGBS) to study the epigenome dynamics of wild strawberry (Fragaria vesca) in response to variable environmental conditions. We showed that the F. vesca methylome responds with great plasticity to ecologically relevant events and that thermal stress results in substantial genome-wide loss of DNA methylation. Stress-induced differential methylation, particularly for non-symmetrical methylation, occurred in hot-spots in potential centromeric regions. Additionally, we identified differentially methylated regions (DMRs) within promoter regions of transcription factor (TF) superfamilies involved in plant stress-response and assessed the effects of the changes on gene expression. This study present methylation patterns in F. vesca and reveal widespread DNA methylation changes in response to abiotic and hormone stresses. These findings will facilitate our understanding of links between DNA methylation and the modulation of gene expression in plants subjected to environmental stresses.