Transcriptional and antagonistic responses of Pseudomonas fluorescens Pf0-1 to phylogenetically different bacterial competitors

• Published in: The ISME Journal Vol. 5; no. 6; pp. 973 - 985
• Main Authors: Garbeva, Paolina, Silby, Mark W, Raaijmakers, Jos M, Levy, Stuart B, Boer, Wietse de
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.06.2011; Oxford University Press; Nature Publishing Group
• Subjects: 631/158/853; 631/208/199; 631/326/2565/855; 631/326/41; aeruginosa; Agar; Alphaproteobacteria - growth & development; Amino Acids - metabolism; Anti-Bacterial Agents - biosynthesis; Antibiosis; Antibiotics; Antimicrobial agents; Bacillus; Bacillus - growth & development; Bacteria; Bacterial Proteins - genetics; Bacteroidetes - growth & development; Biomedical and Life Sciences; biosynthesis; Brevundimonas; chemical communication; Competition; corynebacterium-glutamicum; DNA microarrays; Ecology; Evolutionary Biology; Gene expression; Gene Expression Regulation, Bacterial; Gram-negative bacteria; growth; Life Sciences; Metabolic response; Metabolites; microarray analyses; microbial community composition; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; natural environments; Nutrients; Original; original-article; Pedobacter; Phylogeny; Pseudomonas fluorescens; Pseudomonas fluorescens - genetics; Pseudomonas fluorescens - growth & development; Pseudomonas fluorescens - metabolism; Ribosomal Proteins - genetics; Secondary metabolites; Signal Transduction; Soil; soil bacteria; Soil environment; Soil Microbiology; Soil microorganisms; Soils; Survival; Transcription; Transcription, Genetic; inter-specific interactions; transcriptional responses; bacterial competition; antibiosis
• ISSN: 1751-7362; 1751-7370; 1751-7370
• DOI: 10.1038/ismej.2010.196

The ability of soil bacteria to successfully compete with a range of other microbial species is crucial for their growth and survival in the nutrient-limited soil environment. In the present work, we studied the behavior and transcriptional responses of soil-inhabiting Pseudomonas fluorescens strain Pf0-1 on nutrient-poor agar to confrontation with strains of three phylogenetically different bacterial genera, that is, Bacillus , Brevundimonas and Pedobacter . Competition for nutrients was apparent as all three bacterial genera had a negative effect on the density of P. fluorescens Pf0-1; this effect was most strong during the interaction with Bacillus . Microarray-based analyses indicated strong differences in the transcriptional responses of Pf0-1 to the different competitors. There was higher similarity in the gene expression response of P. fluorescens Pf0-1 to the Gram-negative bacteria as compared with the Gram-positive strain. The Gram-negative strains did also trigger the production of an unknown broad-spectrum antibiotic in Pf0-1. More detailed analysis indicated that expression of specific Pf0-1 genes involved in signal transduction and secondary metabolite production was strongly affected by the competitors’ identity, suggesting that Pf0-1 can distinguish among different competitors and fine-tune its competitive strategies. The results presented here demonstrate that P. fluorescens Pf0-1 shows a species-specific transcriptional and metabolic response to bacterial competitors and provide new leads in the identification of specific cues in bacteria–bacteria interactions and of novel competitive strategies, antimicrobial traits and genes.