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.