MYB37 enhances drought tolerance by maintaining ROS homeostasis and alleviating photosynthetic inhibition in...

Drought is a major abiotic stress that severely limits crop productivity. MYB transcription factors are critical regulators in plant response to environmental stresses. Although previous studies have shown that overexpression of MYB37 improves drought and salt tolerance in Arabidopsis thaliana, its underlying mechanism remains elusive. Here, we demonstrate that MYB37 directly binds to the promoters of ALDH3I1, APX1 and CPN20, and activates their expression under drought conditions, as revealed by ChIP-seq, EMSA and dual-luciferase assays. A conserved binding motif (5'- YYACCWMMH -3') was identified, and genome-wide analysis suggests that MYB37 may directly regulate a significant number of ROS metabolism-related genes in Arabidopsis. Overexpression of MYB37 led to reduced accumulation of superoxide anion (O₂^-), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), while maintaining normal photosynthetic electron transfer and alleviating photoinhibition of PSII and PSI under drought stress. These findings indicate that MYB37 enhances drought tolerance by maintaining ROS homeostasis and protecting the photosynthetic machinery through transcriptional activation of key ROS-scavenging genes.