Arabidopsis glycosyltransferase UGT86A1 promotes plant adaptation to salt and drought stresses.

UDP-glycosyltransferases (UGTs) are the largest glycosyltransferase family developed during the evolution of the plant kingdom. However, their physiological significance in abiotic stress adaptation in land plants is largely unknown. In this study, we identified a UGT gene from Arabidopsis thaliana, UGT86A1, that was significantly induced by salt and drought stresses. To explore the potential biological role of UGT86A1 in salt and drought stress response, we created ugt86a1 knockout mutants and UGT86A1-overexpressing transgenic lines, and analyzed seed germination, seedling development and root growth. The results showed that ugt86a1 mutants are sensitive to drought and salt stresses, while overexpression lines show stronger resistance compared with WT, confirming the positive regulation role of UGT86A1 in abiotic stress response. Our following study indicated that UGT86A1 enhances plant resistance against salt and drought stresses via increasing soluble sugar concentration and promoting ROS scavenging capacity, thereby reducing the damage to plant organs and cells. Moreover, we identified that UGT86A1 largely contributes to the upregulation of multiple stress-induced genes under salt and drought stress conditions. Therefore, our results demonstrated that UGT86A1 is a crucial responsive gene to salt and drought stresses in a land plant, thus promoting the understanding of the physiological significance of the UGT family in plant evolution.