Figure 6. PsVPS1 is required for pathogenicity. A.

Pathogenicity tests on soybean (Hefeng 47) using zoospores from P6497 and PsVPS1-silenced mutants (T22, T30, and T47) inoculated on hypocotyls of etiolated seedlings. Etiolated seedlings were drop-inoculated with equal numbers of effective zoospores (100/10 µl) for 48 h, after which the samples were photographed. Experiments were repeated at least three times. B. Microscopic observations of invasive hyphae in soybean hypocotyls epidermal cells (infectious ostioles, red arrowhead; infectious hyphae, black arrowhead). After 48 hpi, the epidermis of seedling hypocotyls was soaked in Trypan Blue for 20 min, and then washed with SDW. The experiments were repeated three times in all mutants with similar results. Bar indicates 20 µm.