Contribution of phenazine antibiotic biosynthesis to the ecological competence of fluorescent pseudomonads in soil habitats

Mazzola, Mark; Cook, Robert; Thomashow, Linda S.; Weller, David M.; Pierson, Leland S.

doi:10.1128/aem.58.8.2616-2624.1992

Cited by 345 publications

(157 citation statements)

References 46 publications

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“…No significant differential expression could be observed for the genes phnA and pqsA, and similar PQS and HHQ levels were shown under the applied test conditions. The phenazine pyocyanin is a heterocyclic redox-active pigment that exert toxic effects on other prokaryotes and eukaryotes (Mazzola et al, 1992;Mahajan-Miklos et al, 1999), and is produced in response to PQS signalling (Déziel et al, 2004). Recently, Dietrich and colleagues (2006) demonstrated that pyocyanin acts as a terminal signalling molecule in the PQScontrolled QS pathway.…”

Section: Discussionmentioning

confidence: 99%

Use of the rotating wall vessel technology to study the effect of shear stress on growth behaviour of Pseudomonas aeruginosa PA01

Crabbé

Boever

Houdt

et al. 2008

Environmental Microbiology

114

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The biofilm phenotype of Pseudomonas aeruginosa enables this opportunistic pathogen to develop resistance to the immune system and antimicrobial agents. Pseudomonas aeruginosa biofilms are generated under varying levels of shear stress, depending on the infection site. In the lung mucus of cystic fibrosis (CF) patients, P. aeruginosa forms matrix-enclosed microcolonies which cause chronic infections representing the major cause of mortality in CF patients. The lung mucus of CF patients is probably characterized by low fluid shear as the main shear-causing factor, i.e. mucociliary clearance, is absent. In this study, the influence of fluid shear on the growth behaviour of P. aeruginosa PA01 was investigated using a low-shear suspension culture device, the rotating wall vessel (RWV). Cultivation in low shear induced a self-aggregating phenotype of P. aeruginosa PA01, resulting in the formation of biofilms in suspension similar to what has been described in CF mucus. The addition of a ceramic bead to the culture medium in the RWV created a higher-shear condition which led to the formation of surface-attached rather than suspension biofilms. In low-shear culture conditions, a significant increase of the rhl N-butanoyl-l-homoserine lactone (C(4)-HSL) directed quorum sensing (QS) system, and the psl polysaccharide synthetic locus was demonstrated using gene expression analysis. Accordingly, the low-shear condition induced a higher production of rhamnolipids, which is controlled by the C(4)-HSL QS-system and is known to play a role in CF lung pathology. These results indicate that fluid shear has an impact on the growth phenotype of P. aeruginosa which might play a role in CF lung infections caused by this bacterium.

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Section: Discussionmentioning

confidence: 99%

Use of the rotating wall vessel technology to study the effect of shear stress on growth behaviour of Pseudomonas aeruginosa PA01

Crabbé

Boever

Houdt

et al. 2008

Environmental Microbiology

114

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“…PCA is produced in concentrations exceeding 1 mg g 21 root by rhizobacteria in dryland wheat fields throughout the low-precipitation zone of the Columbia Plateau, a major wheat-producing region in central Washington and Oregon, USA (Mavrodi et al, 2012a). Moreover, PCA has been shown to promote the colonization of wheat roots by fluorescent pseudomonads (Mazzola et al, 1992). However, PCA-producing (PCA 1 ) rhizobacteria are not abundant in irrigated fields or in highprecipitation areas within the Columbia Plateau (Mavrodi et al, 2012a,b;.…”

Section: Introductionmentioning

confidence: 99%

Phenazine‐1‐carboxylic acid and soil moisture influence biofilm development and turnover of rhizobacterial biomass on wheat root surfaces

LeTourneau

Marshall

Cliff

et al. 2018

Environmental Microbiology

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Phenazine-1-carboxylic acid (PCA) is produced by rhizobacteria in dryland but not in irrigated wheat fields of the Pacific Northwest, USA. PCA promotes biofilm development in bacterial cultures and bacterial colonization of wheat rhizospheres. However, its impact upon biofilm development has not been demonstrated in the rhizosphere, where biofilms influence terrestrial carbon and nitrogen cycles with ramifications for crop and soil health. Furthermore, the relationships between soil moisture and the rates of PCA biosynthesis and degradation have not been established. In this study, expression of PCA biosynthesis genes was upregulated relative to background transcription, and persistence of PCA was slightly decreased in dryland relative to irrigated wheat rhizospheres. Biofilms in dryland rhizospheres inoculated with the PCA-producing (PCA ) strain Pseudomonas synxantha 2-79RN were more robust than those in rhizospheres inoculated with an isogenic PCA-deficient (PCA ) mutant strain. This trend was reversed in irrigated rhizospheres. In dryland PCA rhizospheres, the turnover of N-labelled rhizobacterial biomass was slower than in the PCA and irrigated PCA treatments, and incorporation of bacterial N into root cell walls was observed in multiple treatments. These results indicate that PCA promotes biofilm development in dryland rhizospheres, and likely influences crop nutrition and soil health in dryland wheat fields.

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“…The most likely such benefit is suppression of nearby fungal or bacterial competitors. For strains such as Pseudomonas fluorescens 2-79 and P. aureofaciens 30-84, the production of phenazine antibiotics contributes to competitiveness on the roots of wheat (Mazzola et al 1992). In contrast, for P. fluorescens F113, the production of the antibiotic 2,4-diacetylphloroglucinol does not appear to be a factor in the competitiveness of the strain on the roots of sugarbeet (Carroll et al 1995).…”

Section: Special Featurementioning

confidence: 98%

Cooperation in the Rhizosphere and the “Free Rider” Problem

Denison

Bledsoe

Kahn

et al. 2003

Ecology

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Rhizobial bacteria, endomycorrhizal fungi (also known as arbuscular mycorrhizas), and pseudomonad bacteria associated with plant roots can provide substantial benefits to the plants by fixing nitrogen, supplying phosphorus, or controlling root pathogens, respectively. A significant fraction of plant photosynthetic carbon may be used by these associated microorganisms, both to support their beneficial activities and for microbial growth and reproduction. Because many microbial individuals are associated with each individual plant, the individual benefit to a microbe that allocates more resources to its own reproduction (thereby allocating less to fixing N2, supplying P, or producing antifungal metabolites) would exceed its individual loss from any resulting reduction in collective benefits (mainly plant carbon substrates). An initially rare “free rider” mutant strain might therefore be expected to displace its more cooperative parental strain. Yet, the mycorrhizal and legume–rhizobium mutualisms have persisted (often coexisting with “cheating”) for millions of years. This paper discusses the importance of microbial cooperation (with plants and with other microbes) and possible reasons for its evolutionary persistence in the rhizosphere. In undisturbed soils, spatial structure can favor kin selection, but this may be counterbalanced by the increased likelihood that future competitors will be among the beneficiaries of current cooperation. In loose associations, direct fitness benefits to microorganisms may explain the evolutionary persistence of activities (e.g., production of antifungal compounds) that can benefit plants as a side effect. In closer, more symbiotic, relationships, host sanctions against individuals or clones that fail to perform their symbiotic function may be more important. New molecular methods and other research tools are facilitating research on this topic, and some of these conclusions soon may be revised. Corresponding Editor: D. A. Phillips. For reprints of this Special Feature, see footnote 1, p. 815

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Contribution of phenazine antibiotic biosynthesis to the ecological competence of fluorescent pseudomonads in soil habitats

Cited by 345 publications

References 46 publications

Use of the rotating wall vessel technology to study the effect of shear stress on growth behaviour of Pseudomonas aeruginosa PA01

Use of the rotating wall vessel technology to study the effect of shear stress on growth behaviour of Pseudomonas aeruginosa PA01

Phenazine‐1‐carboxylic acid and soil moisture influence biofilm development and turnover of rhizobacterial biomass on wheat root surfaces

Cooperation in the Rhizosphere and the “Free Rider” Problem

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