FIG 5.

VdSsk2 of Verticillium dahliae is essential to mount the wild-type response to osmotic agents, fungicides, calcofluor white (CFW), and Congo red (CR). (A) The colony morphology of the wild-type strain XS11, the ΔVdSsk2 and ΔVdSte11 strains, and the respective complemented strains grown on complete medium (CM) or CM supplemented with 0.8 M NaCl, 1.2 M sorbitol, 10 μg/ml fludioxonil, and 5 μg/ml iprodione. Photographs were taken at 8 days. Bar = 1 cm. (B) Colony diameters of the indicated strains. Values are means ± standard deviations (error bars) for three replicates, and asterisks show values that are significantly different (P < 0.01). (C) Chitin distribution was observed in strain XS11, the ΔVdSsk2 strain, and the VdSsk2 complemented strain grown in CM liquid supplemented with 0.6 M NaCl for 4 days. Conidia and hyphae were stained with 10 mg/ml CFW for 5 min. The CFW signal was imaged by fluorescence microscopy, and images were also captured by bright-field microscopy (BF). Bars = 10 μm. (D) The colony morphology of the above XS11 strains were grown on CM containing CFW and CR at 25°C for 5 days. Bar = 0.5 cm. (E) Relative growth inhibition of colonies of each strain. Values are means ± standard deviations (error bars) for three replicates, and asterisks show values that are significantly different (P < 0.01). (F) Expression of three genes associated with cell wall biosynthesis was analyzed by RT-qPCR and normalized against the expression of V. dahliae β-tubulin (7). Values are means plus standard deviations (error bars) for three independent experiments, and asterisks show values that are significantly different (P < 0.01).