A Kinesin Vdkin2 Required for Vacuole Formation, Mycelium Growth, and Penetration Structure Formation of .

The soil-borne vascular fungus infects hundreds of dicotyledonous plants, causing severe wilt diseases. During the initial colonization, develops a penetration peg to enable infection of cotton roots. In some phytopathogenic fungi, vacuoles play a critical role in normal formation of the infection structure. Kinesin 2 protein is associated with vacuole formation in . To identify the function of vacuoles in the infection structure, we identified , an ortholog of kinesin 2, in and investigated its function through gene knockout. mutants showed severe defects in virulence and were suppressed during initial infection and root colonization based on observation of green fluorescent protein-labeled . We also found that deletion of compromised penetration peg formation and the derived septin neck. Disruption strains were viable and showed normal microsclerotia formation, whereas mycelium growth and conidial production were reduced, with shorter and more branched hyphae. Furthermore, the mutant, unlike wild-type , lacked a large basal vacuole, accompanied by a failure to generate concentrated lipid droplets. Taken together, regulates vacuole formation by , which is required for conidiation, mycelium growth, and penetration structure formation during initial plant root infection.