Natural variation in the hrpL promoter renders the phytopathogen Pseudomonas syringae pv. actinidiae nonpathogenic.

ABSTRACT: The genetic basis underlying loss-of-virulence mutations that arise among natural phytopathogen populations is not well documented. In this study, we examined the virulence of 377 isolates of Pseudomonas syringae pv. actinidiae biovar 3 (Psa3) that were isolated from 76 kiwifruit orchards suffering from bacterial canker disease. Eighty-four nonpathogenic isolates were identified in 40 orchards. A nonpathogenic isolate G166 was found to be defective in hrpL transcription and the downstream type III secretion system (T3SS)-dependent phenotypes. Comparative genomics and complementary expression assay revealed that a single-base "G" insertion in the hrpL promoter blocks gene transcription by reducing promoter activity. The electrophoretic mobility shift assay showed that the genetic variation

SUBMITTER: Xie T 

PROVIDER: S-EPMC9923390 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature