The m6A reader AvECT11 regulates ROS metabolism to mediate waterlogging tolerance in Actinidia valvata.

N6-methyladenosine (m6A) is the most abundant RNA modification in eukaryotes and plays a pivotal role in regulating RNA metabolism, including gene expression and translation efficiency. Despite the emerging importance of epitranscriptomic regulation in stress responses, the m6A-mediated adaptive mechanisms to waterlogging stress remain unexplored. Here we identified significantly downregulated AvECT11 as a hypoxia-responsive m6A reader coordinating waterlogging tolerance in Actinidia valvata and Arabidopsis thaliana. Through phenotypic analyses of A. thaliana overexpressing AvECT11 subjected to waterlogging stress and reoxygenation, we found that AvECT11 is a positive regulator for waterlogging stress. Physiological assessments of transgenic roots of A. valvata, including root activity, root conductivity, malondialdehyde (MDA) content, oxygen free radical (O2-), catalase (CAT) activity, and hydrogen peroxide (H2O2) levels, collectively demonstrated that AvECT11 contributes to waterlogging tolerance in A. valvata. Transcriptomic analysis revealed that AvECT11 heavily influences gene expression during waterlogging response in roots, especially genes involved in the reactive oxygen species (ROS) and hydrogen peroxide metabolism, electron transport chain, and regulation of response to alcohol. We further showed that AvECT11 directly binds to transcripts of stress-responsive transcription factors AvARR11-1/2 and ROS metabolism related genes AvATHM4, affecting the stability of their mRNA. These results provide new insights into the molecular mechanisms linking m6A modification for plants to waterlogging adaptation.