Transcriptome-wide N 6 -methyladenosine profiling reveals growth-defense trade-offs in the response of rice to brown planthopper (Nilaparvata lugens) infestation.

Background: N ⁶ -Methyladenosine (m ⁶ A) is a common messenger RNA (mRNA) modification that affects various physiological processes in stress responses. However, the role of m ⁶ A modifications in plants responses to herbivore stress remains unclear.
Results: Here, we found that an infestation of brown planthopper (Nilaparvata lugens) female adults enhanced the resistance of rice to N. lugens. The m ⁶ A methylome analysis of N. lugens-infested and uninfested rice samples was performed to explore the interaction between rice and N. lugens. The m ⁶ A methylation mainly occurred in genes that were actively expressed in rice following N. lugens infestation, while an analysis of the whole-genomic mRNA distribution of m ⁶ A showed that N. lugens infestation caused an overall decrease in the number of m ⁶ A methylation sites across the chromosomes. The m ⁶ A methylation of genes involved in the m ⁶ A modification machinery and several defense-related phytohormones (jasmonic acid and salicylic acid) pathways was increased in N. lugens-infested rice compared to that in uninfested rice. In contrast, m ⁶ A modification levels of growth-related phytohormone (auxin and gibberellin) biosynthesis-related genes were significantly attenuated during N. lugens infestation, accompanied by the down-regulated expression of these transcripts, indicating that rice growth was restricted during N. lugens attack to rapidly optimize resource allocation for plant defense. Integrative analysis of the differential patterns of m ⁶ A methylation and the corresponding transcripts showed a positive correlation between m ⁶ A methylation and transcriptional regulation.
Conclusion: The m ⁶ A modification is an important strategy for regulating the expression of genes involved in rice defense and growth during rice-N. lugens interactions. These findings provide new ideas for formulating strategies to control herbivorous pests. © 2024 Society of Chemical Industry.
(© 2024 Society of Chemical Industry.)