Structural and Mechanistic Insights into FgGWT1 as the Target of Aminopyrifen in Fusarium graminearum : from Binding Pockets Identification to Functional Validation

Fusarium head blight (FHB), caused by Fusarium graminearum, is a globally devastating wheat disease. Currently fungicides face various limitations, including inconsistent effectiveness and resistance risks. Here, we dissect the interaction between aminopyrifen and its target FgGWT1 using molecular dynamics simulation, site-directed mutagenesis, and field trials. FgGWT1 is an ER-resident protein essential for growth, reproduction, and pathogenicity. Deletion of FgGWT1 unexpectedly upregulates TRI gene expression and DON accumulation, revealing a negative regulatory role in mycotoxin biosynthesis. Homology modeling and molecular dynamics simulations further identify five potential binding pockets. Mutagenesis of key residues within these pockets reduces aminopyrifen sensitivity and attenuates pathogenicity, providing functional evidence. Moreover, field evaluations demonstrated the practical potential of aminopyrifen. This work establishes a structural framework for FgGWT1 inhibition, identifies residues governing inhibitor binding and virulence, and provides mechanistic insights for next-generation fungicide development targeting the GPI anchor pathway.