Involvement of Ralfuranone Production in the Virulence of Ralstonia solanacearum OE1‐1. Issue 17 (22nd September 2014) - Kai, Kenji
Abstract Ralstonia solanacearum causes a destructive disease called "bacterial wilt" in numerous plant species. Its virulence is controlled by the transcriptional regulator PhcA, the activity of which is, in turn, regulated in a cell‐density dependent manner, termed quorum sensing. We herein described the identification and characterization of ralfuranones J–L, new PhcA‐regulated secondary metabolites, and the known derivatives, ralfuranones A and B, from R. solanacearum strain OE1‐1. Their structures were determined by spectroscopic and chemical methods. These ralfuranones were also detected in vascular exudates from host plants infected with OE1‐1. Deletion of ralA, which encodes an enzyme for ralfuranone biosynthesis, reduced the virulence of OE1‐1 in tomato plants. Virulence was restored by complementation of the ralA gene. The results suggest that ralfuranones play important roles in the virulence of OE1‐1.