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.