Functional analysis of aromatic biosynthetic pathways in <i>Pseudomonas putida</i> KT2440

Molina‐Henares, María Antonia; García-Salamanca, Adela; Molina‐Henares, Antonio J.; Torre, J. de la; Herrera, Mariano; Ramos, Juan L.; Duque, Estrella

doi:10.1111/j.1751-7915.2008.00062.x

Cited by 23 publications

(25 citation statements)

References 45 publications

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“…, 2007). This study established that, in P. putida KT2440, aromatic amino acid biosynthesis takes place through an interplay of convergent pathways for phenylalanine and tyrosine and a single highly conserved biosynthetic pathway for tryptophan synthesis (Molina‐Henares et al. , 2009).…”

Section: Introductionmentioning

confidence: 85%

Identification of conditionally essential genes for growth ofPseudomonas putidaKT2440 on minimal medium through the screening of a genome‐wide mutant library

Molina‐Henares

Torre

García-Salamanca

et al. 2010

Environmental Microbiology

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SummaryIn silico models for Pseudomonas putida KT2440 metabolism predict 68 genes to be essential for growth on minimal medium. In this study a genomewide collection of single-gene P. putida KT2440 knockouts was generated by mini-Tn5 transposon mutagenesis and used to identify genes essential for growth in minimal medium with glucose. Our screening of the knockout library allowed us to rescue mutants for 48 different knockouts that were conditionally essential for growth on minimal medium. The in vivo screening showed that 24 of these mutants had a insertion in genes proposed to be conditionally essential based on in silico models, whereas another 24 newly implicated conditionally essential genes have been found. For 10 of the in silico proposed conditionally essential genes not found in the screening, knockout mutants were available at the Pseudomonas Reference Culture Collection. These mutants were tested for conditional growth on minimal medium, but none of them was shown to be essential, suggesting that the in silico proposal was inaccurate. Among the set of identified conditionally essential genes were a number of genes involved in the biosynthesis of certain amino acids and vitamins. Auxotrophs for all amino acids predicted by the in silico models were found and, in addition, we also found auxotrophs for proline, serine, threonine and methionine, as well as auxotrophs for biotin, nicotinate and vitamin B12 that were not predicted in silico. Metabolic tests were performed to validate the mutants' phenotypes. Auxotrophies for L-Arg, L-Leu, L-Pro and L-Cys were bypassed by external addition of the corresponding D-amino acids, suggesting the existence of number of D-to L-amino acid racemases encoded by the KT2440 genome. Therefore, the in vivo high-throughput analysis presented here provides relevant insights into the metabolic cross-road of biosynthetic pathways in this microorganism, as well as valuable information for the fine tuning of current in silico metabolic models.

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Section: Introductionmentioning

confidence: 85%

Identification of conditionally essential genes for growth ofPseudomonas putidaKT2440 on minimal medium through the screening of a genome‐wide mutant library

Molina‐Henares

Torre

García-Salamanca

et al. 2010

Environmental Microbiology

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“…Transcripts for the trpAB operon also showed large increases in the cells recovered from plants. In P. putida, trpAB is induced by TrpI in response to indole 3-glycerol phosphate (InGP), whereas trpEFGDC is repressed by TrpI in response to tryptophan (19). Transcripts of trpEFGDC in B728a decreased approximately twofold in both in planta sites (Table S3), suggesting the presence of tryptophan both on and in the leaves.…”

Section: P Syringae Encounters Distinct Environments In Epiphytic Vementioning

confidence: 99%

“…In contrast, the ∼4.2-fold induction of trpAB in epiphytic cells and 1.6-fold induction in apoplastic cells suggest the presence of InGP. A likely source of InGP on leaves is from TrpA-mediated conversion of indole to InGP, which may be converted to tryptophan via TrpAB (19). A likely source of the indole is from the plant, as suggested by the recent demonstration that P. syringae infection of Arabidopsis plants resulted in an increase in Arabidopsis transcripts involved in the synthesis of indole derivatives (17).…”

Section: P Syringae Encounters Distinct Environments In Epiphytic Vementioning

confidence: 99%

Transcriptional responses of Pseudomonas syringae to growth in epiphytic versus apoplastic leaf sites

Yu¹,

Lund

Scott

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

196

268

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Some strains of the foliar pathogen Pseudomonas syringae are adapted for growth and survival on leaf surfaces and in the leaf interior. Global transcriptome profiling was used to evaluate if these two habitats offer distinct environments for bacteria and thus present distinct driving forces for adaptation. The transcript profiles of Pseudomonas syringae pv. syringae B728a support a model in which leaf surface, or epiphytic, sites specifically favor flagellar motility, swarming motility based on 3-(3-hydroxyalkanoyloxy)alkanoic acid surfactant production, chemosensing, and chemotaxis, indicating active relocation primarily on the leaf surface. Epiphytic sites also promote high transcript levels for phenylalanine degradation, which may help counteract phenylpropanoidbased defenses before leaf entry. In contrast, intercellular, or apoplastic, sites favor the high-level expression of genes for GABA metabolism (degradation of these genes would attenuate GABA repression of virulence) and the synthesis of phytotoxins, two additional secondary metabolites, and syringolin A. These findings support roles for these compounds in virulence, including a role for syringolin A in suppressing defense responses beyond stomatal closure. A comparison of the transcriptomes from in planta cells and from cells exposed to osmotic stress, oxidative stress, and iron and nitrogen limitation indicated that water availability, in particular, was limited in both leaf habitats but was more severely limited in the apoplast than on the leaf surface under the conditions tested. These findings contribute to a coherent model of the adaptations of this widespread bacterial phytopathogen to distinct habitats within its host.endophyte | epiphyte | phyllosphere

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“…The bacterial strains cloning vectors and plasmids used in this study have been described before (Molina-Henares et al, 2009;Matilla et al, 2010). Pseudomonas putida BIRD-1 and its mutant derivatives were routinely grown in M9 minimal medium supplemented with glucose [0.5% (w/v)] as the carbon source (Abril et al, 1989).…”

Section: Strains Plasmids and Culture Mediamentioning

confidence: 99%

Analysis of the plant growth‐promoting properties encoded by the genome of the rhizobacterium Pseudomonas putida BIRD‐1

Roca

Pizarro‐Tobías

Udaondo

et al. 2012

Environmental Microbiology

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Pseudomonas putida BIRD-1 is a plant growth-promoting rhizobacterium whose genome size is 5.7 Mbp. It adheres to plant roots and colonizes the rhizosphere to high cell densities even in soils with low moisture. This property is linked to its ability to synthesize trehalose, since a mutant deficient in the synthesis of trehalose exhibited less tolerance to desiccation than the parental strain. The genome of BIRD-1 encodes a wide range of proteins that help it to deal with reactive oxygen stress generated in the plant rhizosphere. BIRD-1 plant growth-promoting rhizobacteria properties derive from its ability to enhance phosphorous and iron solubilization and to produce phytohormones. BIRD-1 is capable of solubilizing insoluble inorganic phosphate forms through acid production. The genome of BIRD-1 encodes at least five phosphatases related to phosphorous solubilization, one of them being a phytase that facilitates the utilization of phytic acid, the main storage form of phosphorous in plants. Pyoverdine is the siderophore produced by this strain, a mutant that in the FvpD siderophore synthase failed to grow on medium without supplementary iron, but the mutant was as competitive as the parental strain in soils because it captures the siderophores produced by other microbes. BIRD-1 overproduces indole-3-acetic acid through convergent pathways.

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Functional analysis of aromatic biosynthetic pathways in Pseudomonas putida KT2440

Cited by 23 publications

References 45 publications

Identification of conditionally essential genes for growth ofPseudomonas putidaKT2440 on minimal medium through the screening of a genome‐wide mutant library

Identification of conditionally essential genes for growth ofPseudomonas putidaKT2440 on minimal medium through the screening of a genome‐wide mutant library

Transcriptional responses of Pseudomonas syringae to growth in epiphytic versus apoplastic leaf sites

Analysis of the plant growth‐promoting properties encoded by the genome of the rhizobacterium Pseudomonas putida BIRD‐1

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