Figure 5.

Deficiency in pathogenicity and appressorial formation of ChSte7 disruption mutants on leaves of Arabidopsis plants. (a) The ChSte7 disruption attenuated pathogenicity on Arabidopsis leaves. Conidia suspensions of wild-type strain Ch-1, ChSte7 disruption mutants ΔChSte7-26 and ΔChSte7-48, and complementation strain CΔChSte7-26-20 were sprayed onto the Arabidopsis leaves incubated at 25°C for 5 days. (b) Conidial suspensions of wild-type strain, ChSte7 disruption mutants, and complementation strain were inoculated onto the surfaces of Arabidopsis leaves and incubated for 4 days. The appressoria of the ChSte7 disruption mutants were not formed, whereas the appressoria of CΔChSte7-26-20 and Ch-1 penetrated epidermal cells and produced abundant invasive hyphae. Ap, appressoria; Co, conidia; Ih, invasive hyphae. Scale bar = 20 μm. (c) Development of infection structures by wild-type strain, ChSte7 disruption mutants, and complementation strain on Arabidopsis leaves at 4 dpi. Ratings for infection structures were given as a percentage of the preceding structure. In each experiment, at least 300 appressoria per strain were examined. Means and standard deviations were calculated from three repeated experiments. Asterisks indicate values significantly different from the wild-type (LSD, P < 0.05), and standard error bars are shown.