Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores.

Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted.

Discovery of Cyclic Lipopeptides Ralstopeptins A and B from Species Complex and Analysis of Biosynthetic Gene Evolution.

species complex (RSSC) strains are plant pathogens that produce lipopeptides (ralstonins and ralstoamides) by the polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) enzyme hybrid. Recently, ralstonins were found to be key molecules in the parasitism of RSSC to other hosts, and fungi. The PKS-NRPS genes of RSSC strains in the GenBank database suggest the production of additional lipopeptides, although it has not been confirmed to date.

Genome- and Mass Spectrometry-Guided Discovery of Ralstoamides A and B from Species Complex.

Strains of species complex (RSSC) are devastating plant pathogens distributed globally with a wide host range and genetic diversity. Many RSSC strains harbor the polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) hybrid gene / for ralstonin production. We report that ralstoamides A () and B (), which are ralstonin-like but shorter lipopeptides, were discovered from the Japanese strains using accumulated RSSC genome data and LC/MS-based metabolite analysis.