Figure 6.

Effect of TolC on expression of genes related to curli biosynthesis. The csgB and csgD expression levels were detected by real-time qRT-PCR. The WT strain (dark columns) and ΔtolC mutant strain (light columns) were grown in M9 or 1/2 M9 medium at 28°C for 1, 3, or 5 days. Ct values were calculated relative to those of the housekeeping rrsG gene using the ΔΔCt method, with the ΔtolC mutant strain values representing the fold change relative to those of the WT strain, which were considered 1. Bars with different hatching patterns represent the average relative expression levels using RNAs from three independent bacterial cultures. Values are shown in means ± standard error of the mean. Statistically significant fold changes between the WT and ΔtolC mutant strains were determined using one-tailed unpaired Student's t-tests. ∗P < 0.05; ∗∗P < 0.01.