FIG 4 .

The low-cell-density-mimicking R. solanacearum ΔphcA mutant uses the nutrients better than the wild-type strain. (A) For each category of available xylem nutrients shown, the stacked bars indicate the number of nutrients that were present in sap from R. solanacearum-infected plants that supported growth of the wild-type strain only (blue), the ΔphcA mutant only (red), both strains (light gray), or neither strain (dark gray). Bacterial growth was scored by measuring A₆₀₀ levels over 72 h at 28°C in minimal broth supplemented with a 10 mM concentration of each indicated nutrient (Table S3) as the sole carbon or nitrogen source. (B) R. solanacearum ΔphcA grew better than the wild-type strain under low-iron conditions. R. solanacearum strains were grown aerobically in BMM broth supplemented with increasing concentrations of ferric chloride (FeCl₃). Bacterial growth was measured as absorbance at 600 nm at 24 h. The data show results from three biological replicates, each performed with three technical replicates (n = 9). Asterisks indicate differences between the strains (ANOVA, P value < 0.001).