A protocol for chemical competence in phytopathogenic Ralstonia

Here, we present a protocol for the transformation of Ralstonia solanacearum species complex (RSSC) strains by calcium chloride-induced chemical competence. We include a step-by-step protocol with media and solution recipes, quantitative results of the protocol’s efficacy for four of five tested RSSC strains, and an explanation of the logic underlying the protocol development. The protocol involves sequentially treating overnight cultures with a cold calcium chloride solution and a cold calcium chloride/magnesium chloride/glycerol solution, transforming through alternating heat shocks and ice incubations, and recovering cells via an outgrowth in rich medium.