S‐nitrosylation of RABG3E positively regulates vesicle trafficking to promote salt tolerance

Abstract Nitric oxide (NO) is a key signaling molecule affecting the response of plants to salt stress; however, the underlying molecular mechanism is poorly understood. In this study, we conducted a phenotype analysis and found that the small GTPase RABG3E (RAB7) promotes salt tolerance in Arabidopsis thaliana . NO promotes the S ‐nitrosylation of RAB7 at Cys‐171, which in turn helps maintain the ion balance in salt‐stressed plants. Furthermore, the S ‐nitrosylation of RAB7 at Cys‐171 enhances the enzyme's GTPase activity, thereby promoting vesicle trafficking and increasing its interaction with phosphatidylinositol phosphates—especially phosphatidylinositol‐4‐phosphate (PI4P). Exogenously applied PI4P increases vesicle trafficking and promotes salt tolerance depending on the S ‐nitrosylation of RAB7 at Cys‐171. These findings illustrate a unique mechanism in salt tolerance, by which NO regulates vesicle trafficking and ion homeostasis through the S ‐nitrosylation of RAB7 and its interaction with PI4P.