Golgi-localized calcium/manganese transporters FgGdt1 and FgPmr1 regulate fungal development and virulence by maintaining Ca and Mn homeostasis in Fusarium graminearum.

Calcium and manganese transporters play important roles in regulating Ca and Mn homeostasis in cells, which is necessary for the normal physiological activities of eukaryotes. Gdt1 and Pmr1 function as calcium/manganese transporters in the Golgi apparatus. However, the functions of Gdt1 and Pmr1 have not been previously characterized in the plant pathogenic fungus Fusarium graminearum. Here, we identified and characterized the biological functions of FgGdt1 and FgPmr1 in F. graminearum. Our study shows that FgGdt1 and FgPmr1 are both localized to the cis- and medial-Golgi. Disruption of FgGdt1 or FgPmr1 in F. graminearum caused serious defects in vegetative growth, conidiation, sexual development and significantly decreased virulence in wheat but increased deoxynivalenol (DON) production. Importantly, FgGdt1 is involved in Ca and Mn homeostasis and the severe phenotypic defects of the ΔFggdt1 mutant were largely due to loss of FgGdt1 function in Mn transportation. FgGdt1-mCherry colocalizes with FgPmr1-GFP at the Golgi, and FgGDT1 exerts its biological function upstream of FgPMR1. Taken together, our results collectively demonstrate that the cis- and medial-Golgi-localized proteins FgGdt1 and FgPmr1 regulate Ca and Mn homeostasis of the Golgi apparatus, and this function is important in modulating the growth, development, DON biosynthesis and pathogenicity of F. graminearum.