FIG 7.

Comparative RNA-seq and phenotypic analysis between wild-type SBW25 and the isogenic mutant devoid of hutC. (A) Volcano plot displaying the differentially expressed genes. Green dots represent upregulated genes, whereas red dots indicate downregulated genes in the ΔhutC mutant. (B) Promoter activities of ′lacZ fusions to P_ntrBC and its variant P_ntrBC-mut2 in the wild-type background. β-Galactosidase assays were performed for cells grown in the defined medium at 6 h after inoculation. Values are means and standard errors from four replicate cultures. (C) Expression of P_plcC-lacZ fusion in wild-type and ΔhutC mutant backgrounds. (D) Agar plates showing the spreading of the wild-type (WT) and ΔhutC strains in LB and minimal salt medium supplemented with succinate (Suc) (20 mM) and histidine (His) (10 mM) or urocanate (Uro) (10 mM). Photos were taken 16 and 36 h after inoculation in 0.3% and 0.5% agar, respectively. (E) Diameters were measured for ten replicate plates in the succinate-plus-histidine medium. (F) Growth dynamics of wild-type SBW25 and the ΔhutC mutant in minimal broth of succinate plus histidine. (G to I) Production of pyoverdine, expressed as relative fluorescence units (RFU), was measured in ten media at 12 (G), 24 (H), and 48 (I) hours after inoculation. Data are means and standard errors from four replicate cultures. Asterisks indicate significant differences (P < 0.05).