Abstract
N 6-methyladenosine (m6A) is a common messenger RNA (mRNA) modification that affects diverse physiological processes in stress responses. However, the role of m6A modification in plants coping with herbivore stress remains unclear. Here we found that an infestation of brown planthopper (BPH) Nilaparvata lugensfemale adults enhanced the rice resistance to BPH. An m6A methylome analysis of BPH-infested and un-infested rice samples were measured to explore the interaction between rice and BPH. m6A methylation occurs mainly in genes actively expressed in rice following BPH infestation, while an analysis of the whole-genomic mRNA distribution of m6A showed that BPH infestation caused an overall decrease in the number of m6A methylation sites across the chromosomes. Genes involved in components of the m6A modification machinery, BPH resistance, and several defense-related (such as JA, SA and cellulose) pathways were heavily methylated by m6A in BPH-infested rice compared to those in un-infested rice. In contrast, m6A modification levels of growth-related phytohormones (auxin and gibberellin) biosynthesis-related genes were significantly attenuated under BPH attack, accompanied by downregulated expression of these transcripts, indicating that rice growth was restricted during BPH attack to rapidly optimize resource allocation for plant defense. Integrative analysis of the differential patterns of m6A methylation and the corresponding transcripts showed a positive correlation between m6A methylation and transcriptional regulation. In conclusion, the process of m6A modification acts as an important strategy for regulating expression of genes involved in rice defense and growth during rice-BPH interaction.