Stage-Specific Genetic Interaction Between and During Vegetative Growth and Conidiation in

CK1 casein kinases are well conserved in filamentous fungi. However, their functions are not well characterized in plant pathogens. In , deletion of caused severe growth defects and loss of conidiation, fertility, and pathogenicity. Interestingly, the mutant was not stable and often produced fast-growing spontaneous suppressors. Suppressor mutations were frequently identified in the gene by sequencing analyses. Deletion of the entire or disruptions of its conserved C-terminal region could suppress the defects of in hyphal growth and conidiation, indicating the genetic relationship between and . Furthermore, the mutant showed defects in polarized growth, cell wall integrity, internalization of FgRho1 and vacuole fusion, which were all partially suppressed by deletion of . Overall, our results indicate a stage-specific functional relationship between and , possibly via FgRho1 signaling for regulating polarized hyphal growth and cell wall integrity.