Fig. 4. Camalexin production, disease development, and cell death progressions in Col-0 and defense-defective mutants. (A) The accumulation of camalexin 48 h after inoculation of Col-0, dnd1-1, and acd2-2 with A. brassicicola strains Ab42464 and Ab40857. Bars with different letters indicate that the corresponding data are significantly different (Duncan’s multiple range test; P < 0.05). The experiment was performed more than three times with similar results. (B) Disease development in Arabidopsis Col-0 wild type and mutants challenged with A. brassicicola strains Ab42464 and Ab40857. The upper panel shows the diameter of a lesion formed 5 days after A. brassicicola inoculation on 5-week-old Arabidopsis leaves. The data points represent the averages with standard errors of measurements of 50 lesions. The lower panel shows the de novo-formed conidia per lesion on the leaves inoculated with A. brassicicola. The data points represent averages with standard errors of measurements of 10 lesions. Bars with different letters indicate that the corresponding data are significantly different (Duncan’s multiple range test; P < 0.05). The experiment was performed more than three times with similar results. (C) Cell death during the early infection stage of an incompatible interaction. Leaves were harvested 12 h after challenge with Ab40857 and stained with trypan blue. Representative samples among 20 leaves from 10 plants are shown. (D) Quantitative analyses of cell death. Samples were harvested as in (C). The data represent averages with standard errors of 5 measurements from 10 plants. Bars with different letters indicate that the corresponding data are significantly different (Duncan’s multiple range test; P < 0.05).