Analysis of the SKWP effectors to bacterial fitness in host plant by a novel competition assay

Abstract

ObjectiveBy testing the internal bacterial growth of SKWP mutants generated in Ralstonia solanacearum strain OE1-1, we evaluated the contribution of these SKWP effectors to bacterial fitness towards host plants. MethodsThe deletion mutant and complementation mutant of R. solanacearum OE1-1 were constructed. A competition assay in mixed infection was adopted to evaluate the contribution of the SKWP to bacterial fitness in tobacco (Nicotiana tabacum cv. Bright Yellow) and eggplant (Solanum melongena cv. Senryo-nigou). ResultsEggplant was the appropriate host for competitive index (CI) assay of R. solanacearum strain OE1-1. All 6 SKWP mutants affected bacterial fitness in eggplant to some extent while SKWP4 appeared to be most important. ConclusionThe SKWP effectors were important for bacterial proliferation in eggplant tissues according to the CI analysis, which paving a new way for further identification of the function on whole SKWP family.