FIG. 4.

Mutations in pacC affect cation efflux at alkaline but not at acidic ambient pH. Kinetics of cation export was determined in germlings of the F. oxysporum wild-type strain (•), loss-of-function mutant pacC^+/− strain (▪), or dominant activating mutant pacC^c strain (▴). Microconidia were germinated for 12 h in SM containing 0.1 M Li⁺ (wild type and pacC^+/− mutant) or 0.3 M Li⁺ (pacC^c mutant), washed, and transferred to Li⁺-free medium buffered at pH 4.0 (A) or 8.0 (B), and samples were taken at the indicated times.