Epitranscriptomic mRNA modifications governing plant stress responses: underlying mechanism and potential application.

Plants inevitably encounter environmental adversities, including abiotic and biotic stresses, which significantly impede plant growth and reduce crop yield. Thus, fine-tuning the fate and function of stress-responsive RNAs is indispensable for plant survival under such adverse conditions. Recently, post-transcriptional RNA modifications have been studied as a potent route to regulate plant gene expression under stress. Among over 160 mRNA modifications identified to date, N 6 -methyladenosine (m 6 A) in mRNAs is notable because of its multifaceted roles in plant development and stress response. Recent transcriptome-wide mapping has revealed the distribution and patterns of m 6 A in diverse stress-responsive mRNAs in plants, building a foundation for elucidating the molecular link between m 6 A and stress response. Moreover, the identification and characterization of m 6 A writers, readers and erasers in Arabidopsis and other model crops have offered insights into the biological roles of m 6 A in plant abiotic stress responses. Here, we review the recent progress of research on mRNA modifications, particularly m 6 A, and their dynamics, distribution, regulation and biological functions in plant stress responses. Further, we posit potential strategies for breeding stress-tolerant crops by engineering mRNA modifications and propose the future direction of research on RNA modifications to gain a much deeper understanding of plant stress biology.