Fig. 5.

The impact of mutation of flhDC and fliA on the T3SS gene expression in D. dadantii 3937 was examined.

A. Promoter activity of fliA was measured using plasmid pAT-fliA in wild-type strain D. dadantii harbouring empty vector pCL1920, the ΔflhDC harbouring empty vector pCL1920 and ΔflhDC harbouring pCL-flhDC.

B and C. Promoter activity of T3SS regulon genes hrpA, hrpN and hrpL was measured in the D. dadantii 3937 harbouring empty vector pCL1920, the ΔflhDC harbouring empty vector pCL1920, the ΔfliA harbouring empty vector pCL1920, and their complemented strains using reporter plasmids pAT-hrpA, pAT-hrpN and pAT-hrpL respectively. Three independent experiments were performed and three replicates were used in each experiment. Values are a representative of three experiments. Error bars indicate standard errors of the means. Asterisks indicate statistically significant differences of the means (P < 0.05 by Student’s t-test).