ABSTRACT PR10/Bet v1‐like proteins are key mediators of plant defence responses against microbial pathogens. Verticillium wilt, caused by the soil‐borne fungus Verticillium dahliae , represents a major threat to global cotton production, yet the functions of PR10/Bet v1‐like proteins in cotton resistance to this disease remain poorly understood. In this study, we characterise GhSTH‐2 , a PR10/Bet v1‐like protein family in cotton, which is strongly upregulated at early stages of V. dahliae infection. Our results demonstrated that GhSTH‐2 acts as a positive regulator of Verticillium wilt resistance and directly interacts with both the V. dahliae effector protein VdEPG1 and the redox‐related protein GhTXNDC9. Silencing of GhSTH‐2 in cotton compromised disease resistance, reduced reactive oxygen species (ROS) bursts, impaired lignin deposition, and downregulated the expression of ROS‐producing genes. Conversely, overexpression of GhSTH‐2 enhanced ROS production and disease resistance in Arabidopsis thaliana . Notably, ROS production was reduced in Δ VdEPG1 ‐infected plants, accompanied by downregulated expression of GhSTH‐2 and GhTXNDC9 , and VdEPG1 was found to suppress GhSTH‐2‐triggered programmed cell death (PCD) and ROS accumulation. Collectively, these results suggest that GhSTH‐2 contributes to cotton immunity by modulating ROS signalling through molecular associations with GhTXNDC9 and VdEPG1, highlighting its potential as a genetic target for enhancing Verticillium wilt resistance.
Zhang et al. (Sun,) studied this question.