Effect of RNA-binding protein nuclear accommodation of mitochondria 8-FgNam8 on deoxynivalenol production and virulence of mycotoxigenic Fusarium graminearum.

RNA-binding proteins (RBPs) are important regulators in RNA metabolism and gene expression in eukaryotes. Emerging studies support that RBPs play important roles in human development, metabolism and various diseases. However, the function of fungal RBPs is less identified and understood. The present study identifies an RBP FgNam8 which is U1 auxiliary component nuclear accommodation of mitochondria 8 (Nam8). The FgNam8 contains three RNA recognition motifs (RRM) and localizes to the cytoplasm and nucleus in F. graminearum. The ΔFgNam8 is reduced in vegetative growth and production of conidia. RNA-seq analyses show multiple RNA-associated biological processes and secondary metabolite biosynthesis pathways are altered in the ΔFgNam8. Furthermore, ΔFgNam8 is significantly reduced in deoxynivalenol (DON) production and virulence. More importantly, we verify the NDR (nuclear Dbf2-related) protein kinase FgCot1 interacts with FgNam8. Taken together, our results indicate that FgNam8 is important for the vegetative development, conidia production, DON production and virulence of F. graminearum, which may help to provide a candidate target for the treatment of Fusarium disease.