N~6-Methyladenine DNA Methylation in Japonica and Indica Rice Genomes and Its Association with Gene Expression, Plant Development, and Stress Responses

【摘要】：N6-Methyladenine(6 mA) DNA methylation has recently been implicated as a potential new epigenetic marker in eukaryotes, including the dicot model Arabidopsis thaliana. However, the conservation and divergence of 6 mA distribution patterns and functions in plants remain elusive. Here we report high-quality 6 mA methylomes at single-nucleotide resolution in rice based on substantially improved genome sequences of two rice cultivars, Nipponbare(Nip; Japonica) and 93-11(Indica). Analysis of 6 mA genomic distribution and its association with transcription suggest that 6 mA distribution and function is rather conserved between rice and Arabidopsis. We found that 6 mA levels are positively correlated with the expression of key stressrelated genes, which may be responsible for the difference in stress tolerance between Nip and 93-11.Moreover, we showed that mutations in DDM1 cause defects in plant growth and decreased 6 mA level.Our results reveal that 6 mA is a conserved DNA modification that is positively associated with gene expression and contributes to key agronomic traits in plants.