Baoqi Li, Mengmeng Zhang, Weinan Sun, Dandan Yue, Yizan Ma, Boyang Zhang, Lingfeng Duan, Maojun Wang, Keith Lindsey, Xinhui Nie, Xianlong Zhang, Xiyan Yang
Plant Biotechnology Journal (2023), doi: 10.1111/pbi.14036
SummaryN6-methyladenosine (m6A) is the most prevalent internal modification present in mRNAs, and isconsidered to participate in a range of developmental and biological processes. Droughtresponse is highly regulated at the genomic, transcriptional and post-transcriptional levels.However, the biological function and regulatory mechanism of m6A modification in the droughtstress response is still poorly understood. We generated a transcriptome-wide m6A map usingdrought-resistant and drought-sensitive varieties of cotton under different water deficientconditions to uncover patterns of m6A methylation in cotton response to drought stress. Theresults reveal that m6A represents a common modification and exhibit dramatic changes indistribution during drought stress. More 5’UTR m6A was deposited in the drought-resistantvariety and was associated with a positive effect on drought resistance by regulating mRNAabundance. Interestingly, we observed that increased m6A abundance was associated withincreased mRNA abundance under drought, contributing to drought resistance, and vice versa.The demethylase GhALKBH10B was found to decrease m6A levels, facilitating the mRNA decayof ABA signal-related genes (GhZEP,GhNCED4andGhPP2CA) and Ca2+signal-related genes(GhECA1,GhCNGC4,GhANN1andGhCML13), and mutation ofGhALKBH10Benhanceddrought resistance at seedling stage in cotton. Virus-induced gene silencing (VIGS) of two Ca2+-related genes,GhECA1andGhCNGC4, reduced drought resistance with the decreased m6Aenrichment on silenced genes in cotton. Collectively, we reveal a novel mechanism of post-transcriptional modification involved in affecting drought response in cotton, by mediating m6Amethylation on targeted transcripts in the ABA and Ca2+signalling transduction pathways.