[Regulation of rsc1285 gene in type III secretion system in Ralstonia solanacearum].

OBJECTIVE: Rsc1285 is one of the putative T3SS-regulated factors in Ralstonia solanacearum, and the regulation of Rsc1285 on T3SS and pathogenicity was characterized. METHODS: The rsc1285 deletion mutants were constructed by homologous recombination and characterized by complementation. RESULTS: The rsc1285 mutant was significantly less virulent than the wild-type strain to infect tomato plants. Rsc1285 controls the expression of hrpB and HrpB-regulating genes, but it is dispensable for the expression of hrpG and prhG. CONCLUSION: R. solanacearum uses Rsc1285 to control the T3SS and pathogenicity via a novel pathway, and this finding provides insights into overall infection mode of R. solanacearum.