The Role and Transcriptional Regulatory Mechanism of Rice OsGSTF5 in the Metabolism of Pretilachlor under Fenclorim Induction

Fenclorim (Fen), an herbicide safener, mitigates pretilachlor (Pre)-induced phytotoxicity in rice, although its molecular mechanism remains unclear. Previous studies have shown that Fen significantly induces OsGSTF5 expression. This study revealed via molecular docking and in vitro assays that the OsGSTF5 protein binds to and metabolizes Pre. Unlike the wild-type plants, the OsGSTF5-overexpressing lines presented Pre tolerance. Cloning the OsGSTF5 promoter (2.0 kb) identified a Fen-responsive cis-element (-1100 to -1500 bp). Yeast one-hybrid screening revealed that four transcription factors (EIL, AP2/ERF, DBB, and C2H2 families) bind the promoter, as validated by dual-luciferase and qRT-PCR assays. The research results establish a Fen (safener)-mediated detoxification network with OsGSTF5 as the core, promoting our understanding of herbicide action mechanisms. Additionally, for the first time, this study clarifies the inductive regulatory mechanism of safeners in rice.