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Quorum-sensing effects in the antagonistic rhizosphere bacterium Serratia plymuthica HRO-C48

Müller, Henry ; Westendorf, Christian ; Leitner, Erich ; Chernin, Leonid ; Riedel, Kathrin ; Schmidt, Silvia ; Eberl, Leo ; Berg, Gabriele

In: FEMS Microbiology Ecology, 2009, vol. 67, no. 3, p. 468-478

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    Titre
    • Quorum-sensing effects in the antagonistic rhizosphere bacterium Serratia plymuthica HRO-C48
    Auteur
    • Müller, Henry. Department of Environmental Biotechnology, Graz University of Technology, Graz, Austria
    • Westendorf, Christian. Department of Environmental Biotechnology, Graz University of Technology, Graz, Austria
    • Leitner, Erich. Department of Food Chemistry and Technology, Graz University of Technology, Graz, Austria
    • Chernin, Leonid. Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agriculture Biotechnology, Hebrew University of Jerusalem, Rehovot, Israel
    • Riedel, Kathrin. Department of Microbiology, Institute of Plant Biology, University of Zürich, Zürich, Switzerland
    • Schmidt, Silvia. Department of Microbiology, Institute of Plant Biology, University of Zürich, Zürich, Switzerland
    • Eberl, Leo. Department of Microbiology, Institute of Plant Biology, University of Zürich, Zürich, Switzerland
    • Berg, Gabriele. Department of Environmental Biotechnology, Graz University of Technology, Graz, Austria
    Type de document
    • Postprint
    Identifiant OAI-PMH
    • oai:doc.rero.ch:303066
    Summary
    The rhizosphere-associated bacterium Serratia plymuthica HRO-C48 is not only able to suppress symptoms caused by soil-borne pathogens but is also able to stimulate growth of plants. Detailed knowledge about the underlying mechanisms and regulation are crucial for the application in biocontrol strategies. To analyse the influence of N-acyl homoserine lactone (AHL)-mediated communication on the biocontrol activity, the AHL-degrading lactonase AiiA was heterologously expressed in the strain, resulting in abolished AHL production. The comparative analysis of the wild type and AHL negative mutants led to the identification of new AHL-regulated phenotypes. In the pathosystem Verticillium dahliae-oilseed rape, the essential role of AHL-mediated signaling for disease suppression was demonstrated. In vitro, the regulatory function of AHLs in the synthesis of the plant growth hormone indole-3-acetic acid is shown for the first time. Additionally, swimming motility was found to be negatively AHL regulated. In contrast, production of extracellular hydrolytic enzymes is shown to be positively AHL-regulated. HRO-C48 emits a broad spectrum of volatile organic compounds that are involved in antifungal activity and, interestingly, whose relative abundances are influenced by quorum sensing (QS). This study shows that QS is crucial for biocontrol activity of S. plymuthica and discusses the impact for the application of the strain as a biocontrol agent