Transcriptome-wide N 6 -methyladenosine profiling of rice responding to
brown planthopper ( Nilaparvata lugens ) infestation reveals
growth–defense trade-offs
Abstract
N 6-methyladenosine (m 6A) is
a common messenger RNA (mRNA) modification that affects diverse
physiological processes in stress responses. However, the role of m
6A modification in plants coping with herbivore stress
remains unclear. Here we found that an infestation of brown planthopper
(BPH) Nilaparvata lugens female adults enhanced the rice
resistance to BPH. An m 6A methylome analysis of
BPH-infested and un-infested rice samples were measured to explore the
interaction between rice and BPH. m 6A methylation
occurs mainly in genes actively expressed in rice following BPH
infestation, while an analysis of the whole-genomic mRNA distribution of
m 6A showed that BPH infestation caused an overall
decrease in the number of m 6A methylation sites
across the chromosomes. Genes involved in components of the m
6A modification machinery, BPH resistance, and several
defense-related (such as JA, SA and cellulose) pathways were heavily
methylated by m 6A in BPH-infested rice compared to
those in un-infested rice. In contrast, m 6A
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 m
6A methylation and the corresponding transcripts
showed a positive correlation between m 6A methylation
and transcriptional regulation. In conclusion, the process of m
6A modification acts as an important strategy for
regulating expression of genes involved in rice defense and growth
during rice-BPH interaction.