Lipopolysaccharides of Pseudomonas spp. that stimulate plant growth

Journal of Bacteriology (Impact Factor: 2.81). 05/1987; 169(4):1441-6.
Source: PubMed


The outer membrane proteins of a series of fluorescent, root-colonizing, plant-growth-stimulating Pseudomonas spp. having been characterized (L. A. de Weger et al., J. Bacteriol. 165:585-594, 1986), the lipopolysaccharides (LPSs) of these strains were examined. The chemical composition of the LPSs of the three best-studied plant-growth-stimulating Pseudomonas strains WCS358, WCS361, and WCS374 and of P. aeruginosa PAO1 as a reference strain was determined and appeared to differ from strain to strain. The 2,6-dideoxy-2-aminosugar quinovasamine was the most abundant compound in the LPS of strain WCS358. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified LPS and of proteinase K-treated cell envelopes revealed ladderlike patterns for most of these strains. These patterns were not substantially influenced by differences in culture conditions. Analysis of proteinase K-treated cell envelopes of 24 root-colonizing Pseudomonas spp. revealed a unique band pattern for each strain, suggesting a great variety in the LPS structures present in these root colonizers. Therefore, electrophoretic analysis of LPS can be used for characterization and identification of the fluorescent root-colonizing Pseudomonas strains.

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Available from: Letty A de Weger
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    • "Pseudomonas isolates can also produce some antibiotic compounds which can inhibit fungi growth [16]. The ability of pseudomonas sp. in stimulating germination and plant growth may be related to some compounds like plant hormones (e.g., gibberellins, cytokinins, indole acetic acid (IAA) and polysaccharides [17] [18] [19]). Using biofertilizers in the biological experiments increased the quantity and quality characters of plant when seeds treated with them [20] [21] [22] [23]. "
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    ABSTRACT: Two experiments were conducted during 2006-2007 in Complete Randomized Design (CRD) to test the biological activity of Pseudomonas bacteria as biocides to protect sesame crop from some fungi and to evaluate its efficiency as plant growth promoting. First experiment investigated the effects of Pseudomonas putida2 and Pseudomonas fluorescens3 on germination and seedlings growth of sesame crop against Pythium, Alternaria and Fusarium under plastic house conditions. Second experiment conducted in large pots to investigate the effects of the two bacterial isolates on some morphological, productive and physiological characters of sesame plants against same fungi under normal conditions. Results showed very low germination and slowly seedlings growth in Pythium, Fusarium and Alternaria treatments respectively, but adding bacterial vaccine of Pseudomonas putida2 and Pseudomonas fluorescens3 as a Biocide to fungi treatments, increased the germination percent and seedlings growth of sesame crop significantly, 20 days after planting compared with control treatment. In the second experiment, control treatment scored germination by 52%, while vaccines of Pseudomonas putida2 and Pseudomonas fluorescence3 treatments increased germination percentage in Fusarium, Pythium and Alternaria treatments significantly in average more than 71%. Both isolates increased significantly Leaf number per plant, leaf area per plant, height of plant, branches number per plant, total dry weight of shoot per plant and chlorophyll content compared with other and control treatments. Similar significant effect for both isolates was recorded in seeds number per pod per plant, total weight of 1,000 seeds per plant and pods number per plant and percentage of N, P, K in total dry weight of shoot per plant and oil percentage in seeds per plant compared with other and control treatments. P. putida2 increased oil percentage in seeds by 43.3, 48.0 and 45.0% respectively while with P. fluorescens3 increased to 42.7, 44.0 and 43.7% respectively compared with control treatment (27.7%). In general Pseudomonas putida2 increased most of growth characters much higher than Pseudomonas fluorescens3, it may related to siderophores compound and genetic factors.
    Full-text · Article · Jan 2011 · Journal of Agricultural Science and Technology
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    • "Analysis of cell envelope protein patterns (Lugtenberg et al., 1975), and analysis of lipopolysaccharide (LPS) ladder patterns (de Weger et al., 1987) by SDS-polyacrylamide gel electrophoresis was performed as described previously (Goldman & Leive, 1980; Palva & Makela, 1980). Cell envelope protein patterns were analyzed after growth of cells in KB and of cells in BM2 medium supplemented with low (0.02 mM) and high (0.5 mM) Mg 21 concentrations. "
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    ABSTRACT: Pseudomonas fluorescens strain PCL1210, a competitive tomato root tip colonization mutant of the efficient root colonizing wild type strain WCS365, is impaired in the two-component sensor-response regulator system ColR/ColS. Here we show that a putative methyltransferase/wapQ operon is located downstream of colR/colS and that this operon is regulated by ColR/ColS. Since wapQ encodes a putative lipopolysaccharide (LPS) phosphatase, the possibility was studied that the integrity of the outer membrane of PCL1210 was altered. Indeed, it was shown that mutant PCL1210 is more resistant to various chemically unrelated antibiotics which have to pass the outer membrane for their action. In contrast, the mutant is more sensitive to the LPS-binding antibiotic polymyxin B. Mutant PCL1210 loses growth in competition with its wild type when grown in tomato root exudate. Mutants in the methyltransferase/wapQ operon are also altered in their outer membrane permeability and are defective in competitive tomato root tip colonization. A model for the altered outer membrane of PCL1210 is discussed.
    Full-text · Article · Dec 2006 · FEMS Microbiology Ecology
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    • "The pseudomonads are a group of bacteria known to play important ecological roles in the soil habitat [3]. Among the roles of the £uorescent pseudomonads of commercial interest are their ability to act as antagonists against plant pathogens because of their production of siderophores and antibiotics [4] [5]. An unintended consequence of the application of the herbicides could be the in£uence on the microbial ecological balance of the soil, leading to a signi¢cant change of the quality of the population. "
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    ABSTRACT: A total of 77 strains of genetically different fluorescent Pseudomonas strains were isolated from an agricultural soil. In pure culture growth experiments the strains were screened for their ability to grow in various concentrations of the sulfonylurea herbicides metsulfuron methyl, chlorsulfuron and thifensulfuron methyl. We found that the presence of the herbicides resulted in a reduction of the growth of the fluorescent pseudomonads. Metsulfuron methyl was shown to be toxic to a major proportion of the strains in low concentrations. Chlorsulfuron was found to be less toxic in low concentrations but toxic in high concentrations. Thifensulfuron methyl was toxic only to a minority of the strains. Indirectly, the growth-reducing effect of the sulfonylurea herbicides was shown to be caused by an inhibition of the enzyme acetolactate synthase. The enzyme is involved in the synthesis of the branched amino acids valine, leucine and isoleucine, and we demonstrated that the toxic effects of the sulfonylurea herbicides could be neutralized when the strains were grown in the presence of an excess amount of the three amino acids.
    Preview · Article · Jan 2006 · FEMS Microbiology Letters
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