Coordination of mA mRNA Methylation and Gene Transcriptome in Sugarcane Response to Drought Stress.

The N-methyladenosine (mA) methylation of mRNA is involved in biological processes essential for plant growth. To explore the mA modification of sugarcane and reveal its regulatory function, methylated RNA immunoprecipitation sequencing (MeRIP-seq) was used to construct the mA map of sugarcane. In this study, mA sites of sugarcane transcriptome were significantly enriched around the stop codon and within 3'-untranslated regions (3'UTR). Gene ontology (GO) analysis showed that the mA modification genes are associated with metabolic biosynthesis. In addition, the mA modification of drought-resistant transcript mRNA increased significantly under drought (DR) treatment, resulting in enhanced mRNA stability, which is involved in regulating sugarcane drought resistance. GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results showed that differentially methylated peak (DMP) modification of differentially expressed genes (DEGs) in DR were particularly associated with abscisic acid (ABA) biosynthesis. The upregulated genes were significantly enriched in the ABA metabolism, ethylene response, fatty acid metabolism, and negative regulation of the abscisic acid activation signaling pathway. These findings provide a basis and resource for sugarcane RNA epigenetic studies and further increase our knowledge of the functions of mA modifications in RNA under abiotic stress.