Discovery of a Novel Fusarium Graminearum Mitogen-Activated Protein Kinase (FgGpmk1) Inhibitor for the Treatment of Fusarium Head Blight

Mitogen-activated protein kinase FgGpmk1 plays vital roles in the development and virulence of Fusarium graminearum (F. graminearum), the causative agent of Fusarium head blight (FHB). However, to date, the druggability of FgGpmk1 still needs verification, and small molecules targeting FgGpmk1 have never been reported. Here, we reported the discovery of a novel inhibitor 94 targeting FgGpmk1. First, a novel hit (compound 21) with an EC₅₀ value of 13.01 μg·mL^-1 against conidial germination of F. graminearum was identified through virtual screening. Then, guided by molecular modeling, compound 94 with an EC₅₀ value of 3.46 μg·mL^-1 was discovered, and it can inhibit the phosphorylation level of FgGpmk1 and influence the nuclear localization of its downstream FgSte12. Moreover, 94 can inhibit deoxynivalenol biosynthesis without any damage to the host. This study reported a group of FgGpmk1 inhibitors with a novel scaffold, which paves the way for the development of potent fungicides to FHB management.