Interpopulation signaling via N-acyl-homoserine lactones among bacteria in the wheat rhizosphere

The biological control bacterium Pseudomonas aureofaciens 30-84 utilizes an N-acyl-homoserine lactone (AHL) signal molecule to control phenazine antibiotic production in the wheat rhizosphere (D. W. Wood and L. S. Pierson III, Gene 168:49-53, 1996). In this study, we demonstrate that naturally co-existing, non-isogenic bacterial populations interact with strain 30-84 at the level of gene expression via the exchange of diffusible signals on wheat roots. Wheat plants from three geographic locations were used to generate a random library of 700 rhizobacterial isolates. Roughly 8% of the isolates from each location restored phenazine gene expression to an AHL-deficient strain of 30-84 in vitro. Five of these isolates were further tested for their ability to influence gene expression of an AHL-deficient reporter of strain 30-84 on wheat roots. All five, isolated from different geographic locations, restored phenazine gene expression by the reporter to wild-type levels. This suggests that in vitro assays can id...

[1]  D. Kaiser,et al.  How and why bacteria talk to each other , 1993, Cell.

[2]  G. Salmond,et al.  The bacterial ‘enigma’: cracking the code of cell–cell communication , 1995, Molecular microbiology.

[3]  E. Greenberg,et al.  Census and consensus in bacterial ecosystems: the LuxR-LuxI family of quorum-sensing transcriptional regulators. , 1996, Annual review of microbiology.

[4]  D. Wood,et al.  Phenazine antibiotic biosynthesis in Pseudomonas aureofaciens 30-84 is regulated by PhzR in response to cell density , 1994, Journal of bacteriology.

[5]  S. Lindow,et al.  An ice nucleation reporter gene system: identification of inducible pathogenicity genes in Pseudomonas syringae pv. phaseolicola. , 1989, The EMBO journal.

[6]  L. Thomashow,et al.  Role of a phenazine antibiotic from Pseudomonas fluorescens in biological control of Gaeumannomyces graminis var. tritici , 1988, Journal of bacteriology.

[7]  G. Salmond,et al.  Quorum sensing: a population-density component in the determination of bacterial phenotype. , 1996, Trends in biochemical sciences.

[8]  K. M. Gray,et al.  Intercellular communication and group behavior in bacteria. , 1997, Trends in microbiology.

[9]  M. Mazzola,et al.  Contribution of phenazine antibiotic biosynthesis to the ecological competence of fluorescent pseudomonads in soil habitats , 1992, Applied and environmental microbiology.

[10]  Gerhard Wanner,et al.  The role of pheromones in bacterial interactions. , 1996 .

[11]  F. Gong,et al.  N-acyl-homoserine lactone-mediated regulation of phenazine gene expression by Pseudomonas aureofaciens 30-84 in the wheat rhizosphere , 1997, Journal of bacteriology.

[12]  D. Wood,et al.  Homoserine lactone-mediated gene regulation in plant-associated bacteria. , 1998, Annual review of phytopathology.

[13]  D. Weller,et al.  Use of mixtures of fluorescent pseudomonads to suppress take-all and improve the growth of wheat , 1994 .

[14]  D. Wood,et al.  The phzI gene of Pseudomonas aureofaciens 30-84 is responsible for the production of a diffusible signal required for phenazine antibiotic production. , 1996, Gene.

[15]  E. Greenberg,et al.  Cross-species induction of luminescence in the quorum-sensing bacterium Vibrio harveyi , 1997, Journal of bacteriology.

[16]  L. Pierson,et al.  Phenazine antibiotic production in Pseudomonas aureofaciens: role in rhizosphere ecology and pathogen suppression , 1996 .

[17]  L. Thomashow,et al.  Cloning and heterologous expression of the phenazine biosynthetic locus from Pseudomonas aureofaciens 30-84. , 1992, Molecular plant-microbe interactions : MPMI.

[18]  K. Rinehart,et al.  Detecting and characterizing N-acyl-homoserine lactone signal molecules by thin-layer chromatography. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[19]  W. Fuqua,et al.  A LuxR-LuxI type regulatory system activates Agrobacterium Ti plasmid conjugal transfer in the presence of a plant tumor metabolite , 1994, Journal of bacteriology.

[20]  J H Lamb,et al.  Quorum sensing and Chromobacterium violaceum: exploitation of violacein production and inhibition for the detection of N-acylhomoserine lactones. , 1997, Microbiology.