Professor Oklahoma State University Stillwater, Oklahoma
Body of Abstract: At the posttranscriptional level, the stress-responsive transcripts undergo alternative splicing, miRNA-mediated regulation, alternative polyadenylation among others. Recent studies have established that the mRNA acquire different modifications such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), andN1-methyladenosine (m1A)and represents a novel layer of post-transcriptional regulation affecting the fate of mRNA life cycle. The importance of m6A in plant growth and development has been appreciated but its significance under stress conditions is only emerging. To assess the role of m6A modification during plant stress responses, we analyzed Me-RIP-seq profiles in Arabidopsis. The results revealed large scale shifts in this modification under stress. The m6A modification is known to affect transcript stability, degradation as well as translation, therefore we examined these processes. Interestingly, we found that the stress-enriched m6A-containing transcripts are more stable and positively correlated with the translation. The significance of the m6A epitranscriptome on abiotic stress tolerance was further assessed using the mta mutant in which the major m6A methyltransferase gene was mutated. The mutant exhibited hypersensitivity to these abiotic stresses as determined by growth, biomass and ROS accumulation coupled with the impaired expression of genes that confers stress tolerance. Taken together, our findings suggest that the m6A epitranscriptome play critical roles in abiotic stress responses of Arabidopsis.