Whole-genome DNA methylation patterns of Oryza sativa (L.) and Oryza glumaepatula (Steud) genotypes associated with aluminum response.

Abstract

Epigenetic mechanisms in crops have emerged as a fundamental factor in plant adaptation and acclimation to biotic and abiotic stresses. Among described epigenetic mechanisms, DNA methylation has been defined as the most studied epigenetic modification involved in several developmental processes. It has been shown that contrasting methylation marks are associated with gene expression variations between cultivated and wild crop species. In this study, we analyzed single‐base resolution methylome maps for Oryza sativa (a cultivated species) and Oryza glumaepatula (a wild species) genotypes grown under control conditions. Our results showed that overall, genome‐wide methylation profiles are mainly conserved between both species, nevertheless, there are several differentially methylated regions with species‐specific methylation patterns. In addition, we analyzed the association of identified DNA methylation marks in relation with Aluminum‐tolerance levels of studied genotypes. We found several differentially methylated regions (DMRs) and DMR‐associated genes (DAGs) that are linked with Al tolerance. Some of these DAGs have been previously reported as differentially expressed under Al exposure in O. sativa . Complementarily a Transposable Elements (TE) analysis revealed that specific aluminum related genes have associated‐TEs potentially regulated by DNA methylation. Interestingly, the DMRs and DAGs between Al‐tolerant and susceptible genotypes were different between O. sativa and O. glumaepatula, suggesting that methylation patterns related to Al responses are unique for each rice species. Our findings provide novel insights into DNA methylation patterns in wild and cultivated rice genotypes and their possible role in the regulation of plant stress responses.