Summary Fusarium oxysporum f. sp. niveum ( Fon ) is a soil‐borne fungus causing vascular Fusarium wilt on watermelon; however, the molecular network regulating Fon virulence remains to be elucidated. Here, we report the function and mechanism of nucleotide sugar transporters (Nsts) in Fon . Fon genome harbours nine FonNst genes with distinct functions in vegetative growth, asexual production, cell wall stress response and viru...