Figure 6.

Antifungal activity of 2-HOT against C. higginsianum and C. orbiculare. A, Arabidopsis leaves that were drop inoculated with spore suspensions of C. higginsianum containing 2-HOT (0, 25, and 50 µm). Images were obtained 7 d after inoculation. Red dots indicate drop-inoculated leaves. B, Number of leaves forming lesions after infection with C. higginsianum. Statistical analyses were performed on three independent infection experiments. Photographs of the infected plants are shown in A and Supplemental Figure S5. C, Effect of 2-HOT on the germination rate of C. higginsianum spores on Arabidopsis leaves. Drops containing spores and the indicated compounds were placed on the leaves and viewed after 1 d. none, Solvent only (0.3% ethanol). Vertical bars indicate sd of three repeated experiments. D, Cucumber cotyledons were drop inoculated with spore suspensions of another species of Colletotrichum, C. orbiculare, containing 2-HOT (0, 25, and 50 µm). Images were obtained 7 d after the inoculation. E, Effect of 2-HOT on the germination rate of C. orbiculare spores. Drops containing spores and the indicated compounds were placed on a microscope slide and viewed after 3 h. none, Solvent only (0.3% ethanol). Vertical bars indicate sd of three repeated experiments. F, Photographs of the germination rate of C. orbiculare spores. Spore suspensions with or without 2-HOT-containing spores and the indicated compounds were placed on a microscope slide and viewed after 3 h. Ap, Appressorium; Co, conidia; none, spore suspension (0.3% ethanol).