Recent discoveries of reversible N6-methyladenosine (m6A) methylation on messenger RNA (mRNA) and mapping of m6A methylomes in mammals and yeast have revealed potential regulatory functions of this RNA modification. In plants, defects in m6A methyltransferase cause an embryo-lethal phenotype, suggesting a critical role of m6A in plant development. Here, we profile m6A transcriptome-wide in two accessions of Arabidopsis thaliana and reveal that m6A is a highly conserved modification of mRNA in plants. Distinct from mammals, m6A in A. thaliana is enriched not only around the stop codon and within 3′-untranslated regions, but also around the start codon. Gene ontology analysis indicates that the unique distribution pattern of m6A in A. thaliana is associated with plant-specific pathways involving the chloroplast. We also discover a positive correlation between m6A deposition and mRNA abundance, suggesting a regulatory role of m6A in plant gene expression. Modification of mRNA with N6-methyladenosine (m6A) is proposed to regulate transcript stability. Here, Jia et al. uncover plant-specific features in the m6A methylome of Arabidopsis, such as methylation enrichment around the start codon, and suggest a positive role in gene expression.

Unique features of the m6A methylome in Arabidopsis thaliana