Detection of plant-modulated alterations in antifungal gene expression in Pseudomonas fluorescens CHA0 on roots by flow cytometry.

Détails

ID Serval
serval:BIB_C150B7680037
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Detection of plant-modulated alterations in antifungal gene expression in Pseudomonas fluorescens CHA0 on roots by flow cytometry.
Périodique
Applied and Environmental Microbiology
Auteur(s)
de Werra P., Baehler E., Huser A., Keel C., Maurhofer M.
ISSN
1098-5336[electronic], 0099-2240[linking]
Statut éditorial
Publié
Date de publication
2008
Volume
74
Numéro
5
Pages
1339-1349
Langue
anglais
Résumé
The biocontrol activity of the root-colonizing Pseudomonas fluorescens strain CHA0 is largely determined by the production of antifungal metabolites, especially 2,4-diacetylphloroglucinol. The expression of these metabolites depends on abiotic and biotic environmental factors, in particular, elements present in the rhizosphere. In this study, we have developed a new method for the in situ analysis of antifungal gene expression using flow cytometry combined with green fluorescent protein (GFP)-based reporter fusions to the phlA and prnA genes essential for the production of the antifungal compounds 2,4-diacetylphloroglucinol and pyrrolnitrin, respectively, in strain CHA0. Expression of phlA-gfp and prnA-gfp in CHA0 cells harvested from the rhizosphere of a set of plant species as well as from the roots of healthy, leaf pathogen-attacked, and physically stressed plants were analyzed using a FACSCalibur. After subtraction of background fluorescence emitted by plant-derived particles and CHA0 cells not carrying the gfp reporters, the average gene expression per bacterial cell could be calculated. Levels of phlA and prnA expression varied significantly in the rhizospheres of different plant species. Physical stress and leaf pathogen infection lowered phlA expression levels in the rhizosphere of cucumber. Our results demonstrate that the newly developed approach is suitable to monitor differences in levels of antifungal gene expression in response to various plant-derived factors. An advantage of the method is that it allows quantification of bacterial gene expression in rhizosphere populations at a single-cell level. To our best knowledge, this is the first study using flow cytometry for the in situ analysis of biocontrol gene expression in a plant-beneficial bacterium in the rhizosphere.
Mots-clé
Antifungal Agents/biosynthesis, Flow Cytometry, Gene Expression Regulation, Bacterial, Pest Control, Biological/methods, Phloroglucinol/analogs & derivatives, Phloroglucinol/metabolism, Plant Roots/microbiology, Pseudomonas fluorescens/metabolism, Pyrrolnitrin/biosynthesis, Species Specificity
Pubmed
Web of science
Création de la notice
13/02/2008 12:58
Dernière modification de la notice
03/03/2018 21:07
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