FlhDC and FliA positively regulate the virulence of D. dadantii 3937 on Chinese cabbage (Brassica campestris). Bacterial cells of the wild-type D. dadantii harbouring empty vector pCL1920, ΔfliA harbouring empty vector pCL1920, ΔfliA harbouring plasmid pCL1920-fliA, ΔflhDC harbouring empty pCL1920, ΔflhDC harbouring pCL1920-flhDC, ΔflhDC harbouring pCL1920-ecpC and ΔflhDC harbouring pCL1920-rsmB strains were inoculated in the leaves of Chinese cabbage. The maceration symptom was measured 24 h post-inoculation. Maceration assays were performed as described in the Experimental procedures. Error bars indicate standard errors of the means. Asterisks indicate statistically significant differences of the means (P < 0.05 by Student’s t-test).