Figure 4.

Virulence assay of Ralstonia solanacearum prhP mutants in (a) tomato plants with petiole inoculation, (b) tomato plants with soil‐soaking inoculation, (c) tobacco plants with leaf infiltration and (d) tobacco plants with soil‐soaking inoculation. The Δfcs/Δnag refers to RQ6207 (RK5050, Δfcs, Δnag). For the soil‐soaking inoculation, a bacterial suspension was poured into pot soil of plants at a final concentration of 10⁷ cfu/g of soil. For the petiole inoculation, 3 µL of bacterial suspension at 10⁸ cfu/mL was dropped onto the freshly cut surface of petioles. For the leaf infiltration, about 50 µL of bacterial suspension at 10⁸ cfu/mL was infiltrated into tobacco leaves with a blunt‐end syringe. Wilt symptoms were inspected daily and scored on a disease index scale from 0 to 4 (0, no wilting; 1, 1–25% wilting; 2, 26–50% wilting; 3, 51–75% wilting; and 4, 76–100% wilted or dead). Each assay was repeated at least with four biological replicates and each trial contained at least 12 plants. Mean values of all results were averaged and presented with SD (error bars), but the SD is not presented in figures for aesthetic reasons. Statistical significance between the prhP mutant (RQ5649) and the wild‐type strain (RK5050) was assessed using a post hoc Dunnett test following ANOVA. Significance level: ** indicates P < 0.01.