N6-Methyladenosine dynamic changes and differential methylation in wheat grain development

Main conclusion More methylation changes occur in late interval than in early interval of wheat seed development with protein and the starch synthesis-related pathway enriched in the later stages. Wheat seed development is a critical process to determining wheat yield and quality, which is controlled by genetics, epigenetics and environments. The N6-methyladenosine (m 6 A) modification is a reversible and dynamic process and plays regulatory role in plant development and stress responses. To better understand the role of m 6 A in wheat grain development, we characterized the m 6 A modification at 10 day post-anthesis (DPA), 20 DPA and 30 DPA in wheat grain development. m 6 A-seq identified 30,615, 30,326, 27,676 high confidence m 6 A peaks from the 10DPA, 20DPA, and 30DPA, respectively, and enriched at 3'UTR. There were 29,964, 29,542 and 26,834 unique peaks identified in AN0942_10d, AN0942_20d and AN0942_30d. One hundred and forty-two genes were methylated by m 6 A throughout seed development, 940 genes methylated in early grain development (AN0942_20d vs AN0942_10d), 1542 genes in late grain development (AN0942_30d vs AN0942_20d), and 1190 genes between early and late development stage (AN0942_30d vs AN0942_10d). KEGG enrichment analysis found that protein-related pathways and the starch synthesis-related pathway were significantly enriched in the later stages of seed development. Our results provide novel knowledge on m 6 A dynamic changes and its roles in wheat grain development.