Figure 5.

Swimming motility and fliC expression in Ralstonia solanacearum strains. (a) To analyse swimming motility, R. solanacearum OE1‐1, ralfuranone‐deficient mutant (ΔralA) and complemented ΔralA mutant (ralA‐comp) strains were grown on one‐quarter‐strength M63 medium solidified with 0.25% agar. The ΔralA mutant was also incubated on agar‐solidified, one‐quarter‐strength M63 medium containing 20 μm ralfuranones A, B, J, K or L. (b) To examine fliC expression, R. solanacearum strains OE1‐1, ΔralA and ralA‐comp were cultured in one‐quarter‐strength M63 medium. The ΔralA mutant was also cultured in one‐quarter‐strength M63 medium containing 20 μm ralfuranones A, B, J, K or L. Total RNA was extracted from a bacterial culture [optical density at 600 nm (OD₆₀₀) = 0.3]. The rpoD gene was used as an internal control for quantitative real‐time polymerase chain reaction. The gene expression levels are presented relative to the rpoD expression level. The experiment was conducted at least twice using independent samples, with similar results. Results for a single representative sample are provided. Values are presented as the mean ± standard deviation of three replicates. Asterisks indicate values that are significantly different from those of the ΔralA strain (P < 0.05, t‐test).