DNA N6-Adenine Methylation in Arabidopsis thaliana

DNA methylation on N6-adenine (6mA) has recently been found to be a potentially epigenetic mark in several unicellular and multicellular eukaryotes. However, its distribution patterns and potential functions in land plants, which are primary producers for most ecosystems, remain largely unknown. Here we report global profiling of 6mA sites at single-nucleotide resolution in the genome of Arabidopsis thaliana at different developmental stages using single-molecule real-time sequencing. 6mA sites are widely distributed across the Arabidopsis genome and enriched over the pericentromeric heterochromatin regions. 6mA occurs more frequently in gene bodies than intergenic regions. Analysis of 6mA methylomes and RNA sequencing data demonstrates that 6mA frequency positively correlates with the gene expression level and the transition from vegetative to reproductive growth in Arabidopsis. Our results uncover 6mA as a DNA mark associated with actively expressed genes in Arabidopsis, suggesting that 6mA serves as a hitherto unknown epigenetic mark in land plants. [Display omitted] •DNA methylation on N6-adenine (6mA) widely occurs in the Arabidopsis genome•6mA is more enriched on gene bodies than intergenic regions•6mA is a dynamic DNA modification during Arabidopsis development•6mA is associated with actively expressed genes in Arabidopsis Characterization of DNA methylation in plants has until now focused mainly on 5-methylcytosine (5mC), which is associated with gene repression. Liang et al. now reveal that methylation on N6-adenine (6mA) is a dynamic DNA modification that is enriched on gene bodies and associated with actively expressed genes in Arabidopsis.