Fgk3 interacts with FgMetR to regulate mycelial growth, conidia development, DON production, and pathogenicity in Fusarium graminearum

Glycogen synthase kinase-3 (Gsk3) is a potential drug target in human medicine, controlling many substrates in cellular processes. In this study, FgMetR was identified as a putative binding partner of Fgk3, the Fusarium graminearum ortholog of Gsk3, although the specific functions of both proteins remain uncharacterized. Notably, the physical interaction between FgMetR and Fgk3 was confirmed via yeast two-hybrid (Y2H) assays, and both proteins were shown to co-localize within the nucleus. FgMetR was vital for mycelial growth, conidia development, deoxynivalenol (DON) production, oxidative stress response, and pathogenicity in F. graminearum. RNA-seq showed the Fgk3 and FgMetR co-regulated ABC transporters pathway and secondary metabolite biosynthesis. This study identified FgMetR as a new interacting protein of Fgk3, and demonstrated its crucial role in the growth, conidiation, DON production, and virulence of F. graminearum. It advanced the understanding of Fgk3 function in filamentous fungi and provided a theoretical basis for preventing Fusarium-related diseases.