Fusarium verticillioides FvPex8 is a key component of peroxisomal docking/translocation module that serves important roles in fumonisin biosynthesis but not in virulence

Peroxisomes are ubiquitous organelles in eukaryotic cells that fulfill various important metabolic functions. In this study, we investigated the role of Docking/Translocation Module (DTM) peroxins, mainly FvPex8, FvPex13, FvPex14, and FvPex33, in Fusarium verticillioides virulence and fumonisin B1 (FB1) biosynthesis. Protein interaction experiments suggested that FvPex13 serves as the core subunit of F. verticillioides DTM. When we generated gene deletion mutants ({Delta}Fvpex8, {Delta}Fvpex13, {Delta}Fvpex14, {Delta}Fvpex33, {Delta}Fvpex33/14) and examined whether the expression of other peroxin genes were affected in the DTM mutants, {Delta}Fvpex8 strain showed most drastic changes to PEX gene expression profiles. Deletion mutants exhibited disparity in carbon source utilization and defect in cell wall integrity when stress agents were applied. Under nutrient starvation, mutants also showed higher levels of lipid droplet accumulation. Notably, {Delta}Fvpex8 mutant showed significant FB1 reduction and altered expression of FUM1 and FUM19 genes. However, FvPex13 was primarily responsible for virulence, while {Delta}Fvpex33/14 double mutant also showed virulence defect. In summary, our study suggests that FvPex13 is the core component of DTM, regulating peroxisome membrane biogenesis as well as PTS1- and PTS2-mediated transmembrane cargo transportation. Importantly, we predict FvPex8 as a key component in DTM that affects peroxisome function in FB1 biosynthesis in F. verticillioides.