1
|
Yang Q, Yan Q, Zhang B, Zhang LQ, Wu X. Citrate Synthase GltA Modulates the 2,4-Diacetylphloroglucinol Biosynthesis of Pseudomonas fluorescens 2P24 and is Essential for the Biocontrol Capacity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:11892-11901. [PMID: 37523467 PMCID: PMC10416347 DOI: 10.1021/acs.jafc.3c03051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 08/02/2023]
Abstract
Carbon metabolism is critical for microbial physiology and remarkably affects the outcome of secondary metabolite production. The production of 2,4-diacetylphloroglucinol (2,4-DAPG), a bacterial secondary metabolite with a broad spectrum of antibiotic activity, is a major mechanism used by the soil bacterium Pseudomonas fluorescens 2P24 to inhibit the growth of plant pathogens and control disease occurrence. Strain 2P24 has evolved a complex signaling cascade to regulate the production of 2,4-DAPG. However, the role of the central carbon metabolism in modulating 2,4-DAPG production has not been fully determined. In this study, we report that the gltA gene, which encodes citrate synthase, affects the expression of the 2,4-DAPG biosynthesis gene and is essential for the biocontrol capacity of strain 2P24. Our data showed that the mutation of gltA remarkably decreased the biosynthesis of 2,4-DAPG. Consistent with this result, the addition of citrate in strain 2P24 resulted in increased 2,4-DAPG production and decreased levels of RsmA and RsmE. In comparison with the wild-type strain, the gltA mutant was severely impaired in terms of biocontrol activity against the bacterial wilt disease of tomato plants caused by Ralstonia solanacearum. Moreover, the gltA mutant exhibited increased antioxidant activity, and the expression of oxidative, stress-associated genes, including ahpB, katB, and oxyR, was significantly upregulated in the gltA mutant compared to the wild-type strain. Overall, our data indicate that the citrate synthase GltA plays an important role in the production of 2,4-DAPG and oxidative stress and is required for biocontrol capacity.
Collapse
Affiliation(s)
- Qingqing Yang
- Guangxi
Key Laboratory of Agro-Environment and Agro-Product Safety/College
of Agriculture, Guangxi University, Nanning 530004, China
| | - Qing Yan
- Department
of Plant Sciences and Plant Pathology, Montana
State University, Bozeman, Montana 59717, United States
| | - Bo Zhang
- Guangxi
Key Laboratory of Agro-Environment and Agro-Product Safety/College
of Agriculture, Guangxi University, Nanning 530004, China
| | - Li-qun Zhang
- College
of Plant Protection, China Agricultural
University, Beijing 100193, China
| | - Xiaogang Wu
- Guangxi
Key Laboratory of Agro-Environment and Agro-Product Safety/College
of Agriculture, Guangxi University, Nanning 530004, China
| |
Collapse
|
2
|
Vick SHW, Fabian BK, Dawson CJ, Foster C, Asher A, Hassan KA, Midgley DJ, Paulsen IT, Tetu SG. Delving into defence: identifying the Pseudomonas protegens Pf-5 gene suite involved in defence against secreted products of fungal, oomycete and bacterial rhizosphere competitors. Microb Genom 2021; 7. [PMID: 34788213 PMCID: PMC8743541 DOI: 10.1099/mgen.0.000671] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Competitive behaviours of plant growth promoting rhizobacteria (PGPR) are integral to their ability to colonize and persist on plant roots and outcompete phytopathogenic fungi, oomycetes and bacteria. PGPR engage in a range of antagonistic behaviours that have been studied in detail, such as the production and secretion of compounds inhibitory to other microbes. In contrast, their defensive activities that enable them to tolerate exposure to inhibitory compounds produced by their neighbours are less well understood. In this study, the genes involved in the Pseudomonas protegens Pf-5 response to metabolites from eight diverse rhizosphere competitor organisms, Fusarium oxysporum, Rhizoctonia solani, Gaeumannomyces graminis var. tritici, Pythium spinosum, Bacillus subtilis QST713, Pseudomonas sp. Q2-87, Streptomyces griseus and Streptomyces bikiniensis subspecies bikiniensi, were examined. Proximity induced excreted metabolite responses were confirmed for Pf-5 with all partner organisms through HPLC before culturing a dense Pf-5 transposon mutant library adjacent to each of these microbes. This was followed by transposon-directed insertion site sequencing (TraDIS), which identified genes that influence Pf-5 fitness during these competitive interactions. A set of 148 genes was identified that were associated with increased fitness during competition, including cell surface modification, electron transport, nucleotide metabolism, as well as regulatory genes. In addition, 51 genes were identified for which loss of function resulted in fitness gains during competition. These included genes involved in flagella biosynthesis and cell division. Considerable overlap was observed in the set of genes observed to provide a fitness benefit during competition with all eight test organisms, indicating commonalities in the competitive response to phylogenetically diverse micro-organisms and providing new insight into competitive processes likely to take place in the rhizosphere.
Collapse
Affiliation(s)
- Silas H W Vick
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia.,Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, Australia.,Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Belinda K Fabian
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, Australia
| | - Catherine J Dawson
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, Australia
| | - Christie Foster
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia
| | - Amy Asher
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia
| | - Karl A Hassan
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, Australia
| | - David J Midgley
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, Australia
| | - Ian T Paulsen
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, Australia
| | - Sasha G Tetu
- Department of Molecular Sciences, Macquarie University, North Ryde, Australia.,ARC Centre of Excellence in Synthetic Biology, Macquarie University, North Ryde, Australia
| |
Collapse
|
3
|
Functional Analysis of Phenazine Biosynthesis Genes in Burkholderia spp. Appl Environ Microbiol 2021; 87:AEM.02348-20. [PMID: 33741619 DOI: 10.1128/aem.02348-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/09/2021] [Indexed: 01/15/2023] Open
Abstract
Burkholderia encompasses a group of ubiquitous Gram-negative bacteria that includes numerous saprophytes as well as species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored, redox-active secondary metabolites called phenazines. Phenazines contribute to competitiveness, biofilm formation, and virulence in the opportunistic pathogen Pseudomonas aeruginosa, but knowledge of their diversity, biosynthesis, and biological functions in Burkholderia is lacking. In this study, we screened publicly accessible genome sequence databases and identified phenazine biosynthesis genes in multiple strains of the Burkholderia cepacia complex, some isolates of the B. pseudomallei clade, and the plant pathogen B. glumae We then focused on B. lata ATCC 17760 to reveal the organization and function of genes involved in the production of dimethyl 4,9-dihydroxy-1,6-phenazinedicarboxylate. Using a combination of isogenic mutants and plasmids carrying different segments of the phz locus, we characterized three novel genes involved in the modification of the phenazine tricycle. Our functional studies revealed a connection between the presence and amount of phenazines and the dynamics of biofilm growth in flow cell and static experimental systems but at the same time failed to link the production of phenazines with the capacity of Burkholderia to kill fruit flies and rot onions.IMPORTANCE Although the production of phenazines in Burkholderia was first reported almost 70 years ago, the role these metabolites play in the biology of these economically important microorganisms remains poorly understood. Our results revealed that the phenazine biosynthetic pathway in Burkholderia has a complex evolutionary history, which likely involved horizontal gene transfers among several distantly related groups of organisms. The contribution of phenazines to the formation of biofilms suggests that Burkholderia, like fluorescent pseudomonads, may benefit from the unique redox-cycling properties of these versatile secondary metabolites.
Collapse
|
4
|
Coleman SR, Pletzer D, Hancock REW. Contribution of Swarming Motility to Dissemination in a Pseudomonas aeruginosa Murine Skin Abscess Infection Model. J Infect Dis 2020; 224:726-733. [PMID: 33349847 DOI: 10.1093/infdis/jiaa778] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 12/16/2020] [Indexed: 01/21/2023] Open
Abstract
Swarming motility in Pseudomonas aeruginosa is a multicellular adaptation induced by semisolid medium with amino acids as a nitrogen source. By phenotypic screening, we differentiated swarming from other complex adaptive phenotypes, such as biofilm formation, swimming and twitching, by identifying a swarming-specific mutant in ptsP, a metabolic regulator. This swarming-deficient mutant was tested in an acute murine skin abscess infection model. Bacteria were recovered at significantly lower numbers from organs of mice infected with the ∆ptsP mutant. We also tested the synthetic peptide 1018 for activity against different motilities and efficacy in vivo. Treatment with peptide 1018 mimicked the phenotype of the ∆ptsP mutant in vitro, as swarming was inhibited at low concentrations (<2 μg/mL) but not swimming or twitching, and in vivo, as mice had a reduced bacterial load recovered from organs. Therefore, PtsP functions as a regulator of swarming, which in turn contributes to dissemination and colonization in vivo.
Collapse
Affiliation(s)
- Shannon R Coleman
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Daniel Pletzer
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.,Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| |
Collapse
|
5
|
Metabolic and Genomic Traits of Phytobeneficial Phenazine-Producing Pseudomonas spp. Are Linked to Rhizosphere Colonization in Arabidopsis thaliana and Solanum tuberosum. Appl Environ Microbiol 2020; 86:AEM.02443-19. [PMID: 31811040 DOI: 10.1128/aem.02443-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 12/03/2019] [Indexed: 01/01/2023] Open
Abstract
Bacterial rhizosphere colonization is critical for phytobeneficial rhizobacteria such as phenazine-producing Pseudomonas spp. To better understand this colonization process, potential metabolic and genomic determinants required for rhizosphere colonization were identified using a collection of 60 phenazine-producing Pseudomonas strains isolated from multiple plant species and representative of the worldwide diversity. Arabidopsis thaliana and Solanum tuberosum (potato) were used as host plants. Bacterial rhizosphere colonization was measured by quantitative PCR using a newly designed primer pair and TaqMan probe targeting a conserved region of the phenazine biosynthetic operon. The metabolic abilities of the strains were assessed on 758 substrates using Biolog phenotype microarray technology. These data, along with available genomic sequences for all strains, were analyzed in light of rhizosphere colonization. Strains belonging to the P. chlororaphis subgroup colonized the rhizospheres of both plants more efficiently than strains belonging to the P. fluorescens subgroup. Metabolic results indicated that the ability to use amines and amino acids was associated with an increase in rhizosphere colonization capability in A. thaliana and/or in S. tuberosum The presence of multiple genetic determinants in the genomes of the different strains involved in catabolic pathways and plant-microbe and microbe-microbe interactions correlated with increased or decreased rhizosphere colonization capabilities in both plants. These results suggest that the metabolic and genomic traits found in different phenazine-producing Pseudomonas strains reflect their rhizosphere competence in A. thaliana and S. tuberosum Interestingly, most of these traits are associated with similar rhizosphere colonizing capabilities in both plant species.IMPORTANCE Rhizosphere colonization is crucial for plant growth promotion and biocontrol by antibiotic-producing Pseudomonas spp. This colonization process relies on different bacterial determinants which partly remain to be uncovered. In this study, we combined a metabolic and a genomic approach to decipher new rhizosphere colonization determinants which could improve our understanding of this process in Pseudomonas spp. Using 60 distinct strains of phenazine-producing Pseudomonas spp., we show that rhizosphere colonization abilities correlated with both metabolic and genomic traits when these bacteria were inoculated on two distant plants, Arabidopsis thaliana and Solanum tuberosum Key metabolic and genomic determinants presumably required for efficient colonization of both plant species were identified. Upon further validation, these targets could lead to the development of simple screening tests to rapidly identify efficient rhizosphere colonizers.
Collapse
|
6
|
Dual-stressor selection alters eco-evolutionary dynamics in experimental communities. Nat Ecol Evol 2018; 2:1974-1981. [DOI: 10.1038/s41559-018-0701-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/24/2018] [Indexed: 11/08/2022]
|
7
|
Lee GH, Ryu CM. Spraying of Leaf-Colonizing Bacillus amyloliquefaciens Protects Pepper from Cucumber mosaic virus. PLANT DISEASE 2016; 100:2099-2105. [PMID: 30682996 DOI: 10.1094/pdis-03-16-0314-re] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Beneficial plant-associated bacteria protect host plants against pathogens, including viruses. However, leaf-associated (phyllosphere) bacteria have rarely been investigated as potential triggers of plant systemic defense against plant viruses. We found that leaf-colonizing Bacillus amyloliquefaciens strain 5B6 (isolated from a cherry tree leaf) protected Nicotiana benthamiana and pepper plants against Cucumber mosaic virus (CMV). In a field trial, treatment with strain 5B6 significantly reduced the relative contents of CMV coat protein RNA compared with the water control over a 3-year period, as revealed by quantitative reverse-transcription polymerase chain reaction. The expression of Capsicum annuum pathogenesis-related (PR) genes CaPR4, CaPR5, and CaPR10 was upregulated in field-grown pepper plants treated with strain 5B6. In addition, the accumulation of two naturally occurring viruses, Broad bean wilt virus and Pepper mottle virus, was reduced by foliar treatment with strain 5B6, which is similar to the results for benzothiadiazole treatment as a positive control. Taken together, the results suggest that strain 5B6 has strong potential for protecting plants against viruses by increasing defense priming of salicylic acid and jasmonic acid signaling in pepper under field conditions. This is the first report of the protection of a plant against viral diseases by foliar application of leaf-associated bacilli.
Collapse
Affiliation(s)
- Ga Hyung Lee
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, KRIBB, Daejeon 305-806, South Korea
| | - Choong-Min Ryu
- Molecular Phytobacteriology Laboratory, Super-Bacteria Research Center, KRIBB, Daejeon 305-806, South Korea, and Biosystems and Bioengineering Program, University of Science and Technology, Daejeon 305-350, South Korea
| |
Collapse
|
8
|
Jousset A, Eisenhauer N, Merker M, Mouquet N, Scheu S. High functional diversity stimulates diversification in experimental microbial communities. SCIENCE ADVANCES 2016; 2:e1600124. [PMID: 27386573 PMCID: PMC4928988 DOI: 10.1126/sciadv.1600124] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 06/03/2016] [Indexed: 05/30/2023]
Abstract
There is a growing awareness that biodiversity not only drives ecosystem services but also affects evolutionary dynamics. However, different theories predict contrasting outcomes on when do evolutionary processes occur within a context of competition. We tested whether functional diversity can explain diversification patterns. We tracked the survival and diversification of a focal bacterial species (Pseudomonas fluorescens) growing in bacterial communities of variable diversity and composition. We found that high functional diversity reduced the fitness of the focal species and, at the same time, fostered its diversification. This pattern was linked to resource competition: High diversity increased competition on a portion of the resources while leaving most underexploited. The evolved phenotypes of the focal species showed a better use of underexploited resources, albeit at a cost of lower overall growth rates. As a result, diversification alleviated the impact of competition on the fitness of the focal species. We conclude that biodiversity can stimulate evolutionary diversification, provided that sufficient alternative niches are available.
Collapse
Affiliation(s)
- Alexandre Jousset
- J.F. Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Berliner Straße 28, 37073 Göttingen, Germany
- Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, Netherlands
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
- Institute of Biology, Leipzig University, Johannisallee 21, 04103 Leipzig, Germany
| | - Monika Merker
- J.F. Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Berliner Straße 28, 37073 Göttingen, Germany
| | - Nicolas Mouquet
- Institut des Sciences de l’Evolution, UMR 5554, CNRS, Université Montpellier 2, CC 065, Place Eugène Bataillon, 34095 Montpellier, Cedex 05, France
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université Montpellier, CC 093, FR-34095 Montpellier, Cedex 5, France
| | - Stefan Scheu
- J.F. Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Berliner Straße 28, 37073 Göttingen, Germany
| |
Collapse
|
9
|
Bankhead SB, Thomashow LS, Weller DM. Rhizosphere Competence of Wild-Type and Genetically Engineered Pseudomonas brassicacearum Is Affected by the Crop Species. PHYTOPATHOLOGY 2016; 106:554-561. [PMID: 26926486 DOI: 10.1094/phyto-09-15-0244-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
2,4-Diacetylphloroglucinol (2,4-DAPG)-producing Pseudomonas brassicacearum Q8r1-96 is a highly effective biocontrol agent of take-all disease of wheat. Strain Z30-97, a recombinant derivative of Q8r1-96 containing the phzABCDEFG operon from P. synxantha (formerly P. fluorescens) 2-79 inserted into its chromosome, also produces phenazine-1-carboxylic acid. Rhizosphere population sizes of Q8r1-96, Z30-97, and 2-79, introduced into the soil, were assayed during successive growth cycles of barley, navy bean, or pea under controlled conditions as a measure of the impact of crop species on rhizosphere colonization of each strain. In the barley rhizosphere, Z30-96 colonized less that Q8r1-96 when they were introduced separately, and Q8r1-96 out-competed Z30-96 when the strains were introduced together. In the navy bean rhizosphere, Q8r1-96 colonized better than Z30-97 when the strains were introduced separately. However, both strains had similar population densities when introduced together. Strain Q8r1-96 and Z30-97 colonized the pea rhizosphere equally well when each strain was introduced separately, but Z30-97 out-competed Q8r1-96 when they were introduced together. To our knowledge, this is the first report of a recombinant biocontrol strain of Pseudomonas spp. gaining rhizosphere competitiveness on a crop species. When assessing the potential fate of and risk posed by a recombinant Pseudomonas sp. in soil, both the identity of the introduced genes and the crop species colonized by the recombinant strain need to be considered.
Collapse
Affiliation(s)
- Stacey Blouin Bankhead
- First author: Department of Crop and Soil Sciences, Washington State University, Pullman 99164-6420; and second and third authors: U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430
| | - Linda S Thomashow
- First author: Department of Crop and Soil Sciences, Washington State University, Pullman 99164-6420; and second and third authors: U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430
| | - David M Weller
- First author: Department of Crop and Soil Sciences, Washington State University, Pullman 99164-6420; and second and third authors: U.S. Department of Agriculture, Agricultural Research Service, Wheat Health, Genetics and Quality Research Unit, Pullman, WA 99164-6430
| |
Collapse
|
10
|
Godino A, Príncipe A, Fischer S. A ptsP deficiency in PGPR Pseudomonas fluorescens SF39a affects bacteriocin production and bacterial fitness in the wheat rhizosphere. Res Microbiol 2015; 167:178-89. [PMID: 26708985 DOI: 10.1016/j.resmic.2015.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 12/04/2015] [Accepted: 12/07/2015] [Indexed: 11/26/2022]
Abstract
Pseudomonas fluorescens SF39a is a plant-growth-promoting bacterium isolated from wheat rhizosphere. In this report, we demonstrate that this native strain secretes bacteriocins that inhibit growth of phytopathogenic strains of the genera Pseudomonas and Xanthomonas. An S-type pyocin gene was detected in the genome of strain SF39a and named pys. A non-polar pys::Km mutant was constructed. The bacteriocin production was impaired in this mutant. To identify genes involved in bacteriocin regulation, random transposon mutagenesis was carried out. A miniTn5Km1 mutant, called P. fluorescens SF39a-451, showed strongly reduced bacteriocin production. This phenotype was caused by inactivation of the ptsP gene which encodes a phosphoenolpyruvate phosphotransferase (EI(Ntr)) of the nitrogen-related phosphotransferase system (PTS(Ntr)). In addition, this mutant showed a decrease in biofilm formation and protease production, and an increase in surface motility and pyoverdine production compared with the wild-type strain. Moreover, we investigated the ability of strain SF39a-451 to colonize the wheat rhizosphere under greenhouse conditions. Interestingly, the mutant was less competitive than the wild-type strain in the rhizosphere. To our knowledge, this study provides the first evidence of both the relevance of the ptsP gene in bacteriocin production and functional characterization of a pyocin S in P. fluorescens.
Collapse
Affiliation(s)
- Agustina Godino
- Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36-Km 601-5800, Río Cuarto, Córdoba, Argentina.
| | - Analía Príncipe
- Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36-Km 601-5800, Río Cuarto, Córdoba, Argentina.
| | - Sonia Fischer
- Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36-Km 601-5800, Río Cuarto, Córdoba, Argentina.
| |
Collapse
|
11
|
Lee J, Park YH, Kim YR, Seok YJ, Lee CR. Dephosphorylated NPr is involved in an envelope stress response of Escherichia coli. MICROBIOLOGY-SGM 2015; 161:1113-1123. [PMID: 25701731 PMCID: PMC4635465 DOI: 10.1099/mic.0.000056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/10/2015] [Indexed: 01/20/2023]
Abstract
Besides the canonical phosphoenolpyruvate-dependent phosphotransferase system (PTS) for carbohydrate transport, most Proteobacteria possess the so-called nitrogen PTS (PTSNtr) that transfers a phosphate group from phosphoenolpyruvate (PEP) over enzyme INtr (EINtr) and NPr to enzyme IIANtr (EIIANtr). The PTSNtr lacks membrane-bound components and functions exclusively in a regulatory capacity. While EIIANtr has been implicated in a variety of cellular processes such as potassium homeostasis, phosphate starvation, nitrogen metabolism, carbon metabolism, regulation of ABC transporters and poly-β-hydroxybutyrate accumulation in many Proteobacteria, the only identified role of NPr is the regulation of biosynthesis of the lipopolysaccharide (LPS) layer by direct interaction with LpxD in Escherichia coli. In this study, we provide another phenotype related to NPr. Several lines of evidence demonstrate that E. coli strains with increased levels of dephosphorylated NPr are sensitive to envelope stresses, such as osmotic, ethanol and SDS stresses, and these phenotypes are independent of LpxD. The C-terminal region of NPr plays an important role in sensitivity to envelope stresses. Thus, our data suggest that the dephospho-form of NPr affects adaptation to envelope stresses through a C-terminus-dependent mechanism.
Collapse
Affiliation(s)
- Jaeseop Lee
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido 449-728, Republic of Korea
| | - Young-Ha Park
- Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Yeon-Ran Kim
- Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Yeong-Jae Seok
- Department of Biophysics and Chemical Biology, Seoul National University, Seoul 151-742, Republic of Korea.,Department of Biological Sciences and Institute of Microbiology, Seoul National University, Seoul 151-742, Republic of Korea
| | - Chang-Ro Lee
- Department of Biological Sciences, Myongji University, Yongin, Gyeonggido 449-728, Republic of Korea
| |
Collapse
|
12
|
Hernández-Salmerón JE, Valencia-Cantero E, Santoyo G. Genome-wide analysis of long, exact DNA repeats in rhizobia. Genes Genomics 2013. [DOI: 10.1007/s13258-012-0052-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Kwak YS, Weller DM. Take-all of Wheat and Natural Disease Suppression: A Review. THE PLANT PATHOLOGY JOURNAL 2013; 29:125-35. [PMID: 25288939 PMCID: PMC4174779 DOI: 10.5423/ppj.si.07.2012.0112] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 09/19/2012] [Accepted: 09/25/2012] [Indexed: 05/03/2023]
Abstract
In agro-ecosystems worldwide, some of the most important and devastating diseases are caused by soil-borne necrotrophic fungal pathogens, against which crop plants generally lack genetic resistance. However, plants have evolved approaches to protect themselves against pathogens by stimulating and supporting specific groups of beneficial microorganisms that have the ability to protect either by direct inhibition of the pathogen or by inducing resistance mechanisms in the plant. One of the best examples of protection of plant roots by antagonistic microbes occurs in soils that are suppressive to take-all disease of wheat. Take-all, caused by Gaeumannomyces graminis var. tritici, is the most economically important root disease of wheat worldwide. Take-all decline (TAD) is the spontaneous decline in incidence and severity of disease after a severe outbreak of take-all during continuous wheat or barley monoculture. TAD occurs worldwide, and in the United States and The Netherlands it results from a build-up of populations of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent Pseudomonas spp. during wheat monoculture. The antibiotic 2,4-DAPG has a broad spectrum of activity and is especially active against the take-all pathogen. Based on genotype analysis by repetitive sequence-based-PCR analysis and restriction fragment length polymorphism of phlD, a key 2,4-DAPG biosynthesis gene, at least 22 genotypes of 2,4-DAPG producing fluorescent Pseudomonas spp. have been described worldwide. In this review, we provide an overview of G. graminis var. tritici, the take-all disease, Pseudomonas biocontrol agents, and mechanism of disease suppression.
Collapse
Affiliation(s)
- Youn-Sig Kwak
- Department of Applied Biology and Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 660-701, Korea
- Corresponding author. Phone) +82-55-772-1922, FAX) +82-55-772-1929, E-mail)
| | - David M. Weller
- United States Department of Agriculture, Agricultural Research Service, Root Disease and Biological Control Research Unit, Pullman, WA 99164-6430, USA
| |
Collapse
|
14
|
Redondo-Nieto M, Barret M, Morrissey J, Germaine K, Martínez-Granero F, Barahona E, Navazo A, Sánchez-Contreras M, Moynihan JA, Muriel C, Dowling D, O'Gara F, Martín M, Rivilla R. Genome sequence reveals that Pseudomonas fluorescens F113 possesses a large and diverse array of systems for rhizosphere function and host interaction. BMC Genomics 2013; 14:54. [PMID: 23350846 PMCID: PMC3570484 DOI: 10.1186/1471-2164-14-54] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 01/23/2013] [Indexed: 01/04/2023] Open
Abstract
Background Pseudomonas fluorescens F113 is a plant growth-promoting rhizobacterium (PGPR) isolated from the sugar-beet rhizosphere. This bacterium has been extensively studied as a model strain for genetic regulation of secondary metabolite production in P. fluorescens, as a candidate biocontrol agent against phytopathogens, and as a heterologous host for expression of genes with biotechnological application. The F113 genome sequence and annotation has been recently reported. Results Comparative analysis of 50 genome sequences of strains belonging to the P. fluorescens group has revealed the existence of five distinct subgroups. F113 belongs to subgroup I, which is mostly composed of strains classified as P. brassicacearum. The core genome of these five strains is highly conserved and represents approximately 76% of the protein-coding genes in any given genome. Despite this strong conservation, F113 also contains a large number of unique protein-coding genes that encode traits potentially involved in the rhizocompetence of this strain. These features include protein coding genes required for denitrification, diterpenoids catabolism, motility and chemotaxis, protein secretion and production of antimicrobial compounds and insect toxins. Conclusions The genome of P. fluorescens F113 is composed of numerous protein-coding genes, not usually found together in previously sequenced genomes, which are potentially decisive during the colonisation of the rhizosphere and/or interaction with other soil organisms. This includes genes encoding proteins involved in the production of a second flagellar apparatus, the use of abietic acid as a growth substrate, the complete denitrification pathway, the possible production of a macrolide antibiotic and the assembly of multiple protein secretion systems.
Collapse
Affiliation(s)
- Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin, 2, Madrid, 28049, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Naushad HS, Gupta RS. Phylogenomics and molecular signatures for species from the plant pathogen-containing order xanthomonadales. PLoS One 2013; 8:e55216. [PMID: 23408961 DOI: 10.1016/j.biocontrol.2008.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 12/19/2012] [Indexed: 05/20/2023] Open
Abstract
The species from the order Xanthomonadales, which harbors many important plant pathogens and some human pathogens, are currently distinguished primarily on the basis of their branching in the 16S rRNA tree. No molecular or biochemical characteristic is known that is specific for these bacteria. Phylogenetic and comparative analyses were conducted on 26 sequenced Xanthomonadales genomes to delineate their branching order and to identify molecular signatures consisting of conserved signature indels (CSIs) in protein sequences that are specific for these bacteria. In a phylogenetic tree based upon sequences for 28 proteins, Xanthomonadales species formed a strongly supported clade with Rhodanobacter sp. 2APBS1 as its deepest branch. Comparative analyses of protein sequences have identified 13 CSIs in widely distributed proteins such as GlnRS, TypA, MscL, LysRS, LipA, Tgt, LpxA, TolQ, ParE, PolA and TyrB that are unique to all species/strains from this order, but not found in any other bacteria. Fifteen additional CSIs in proteins (viz. CoxD, DnaE, PolA, SucA, AsnB, RecA, PyrG, LigA, MutS and TrmD) are uniquely shared by different Xanthomonadales except Rhodanobacter and in a few cases by Pseudoxanthomonas species, providing further support for the deep branching of these two genera. Five other CSIs are commonly shared by Xanthomonadales and 1-3 species from the orders Chromatiales, Methylococcales and Cardiobacteriales suggesting that these deep branching orders of Gammaproteobacteria might be specifically related. Lastly, 7 CSIs in ValRS, CarB, PyrE, GlyS, RnhB, MinD and X001065 are commonly shared by Xanthomonadales and a limited number of Beta- or Gamma-proteobacteria. Our analysis indicates that these CSIs have likely originated independently and they are not due to lateral gene transfers. The Xanthomonadales-specific CSIs reported here provide novel molecular markers for the identification of these important plant and human pathogens and also as potential targets for development of drugs/agents that specifically target these bacteria.
Collapse
Affiliation(s)
- Hafiz Sohail Naushad
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | | |
Collapse
|
16
|
Erni B. The bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS): an interface between energy and signal transduction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2012. [DOI: 10.1007/s13738-012-0185-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
17
|
The multifactorial basis for plant health promotion by plant-associated bacteria. Appl Environ Microbiol 2011; 77:1548-55. [PMID: 21216911 DOI: 10.1128/aem.01867-10] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
On plants, microbial populations interact with each other and their host through the actions of secreted metabolites. However, the combined action of diverse organisms and their different metabolites on plant health has yet to be fully appreciated. Here, the multifactorial nature of these interactions, at the organismal and molecular level, leading to the biological control of plant diseases is reviewed. To do so, we describe in detail the ecological significance of three different classes of secondary metabolites and discuss how they might contribute to biological control. Specifically, the roles of auxin, acetoin, and phenazines are considered, because they represent very different but important types of secondary metabolites. We also describe how studies of the global regulation of bacterial secondary metabolism have led to the discovery of new genes and phenotypes related to plant health promotion. In conclusion, we describe three avenues for future research that will help to integrate these complex and diverse observations into a more coherent synthesis of bacterially mediated biocontrol of plant diseases.
Collapse
|
18
|
Structural and functional analysis of the type III secretion system from Pseudomonas fluorescens Q8r1-96. J Bacteriol 2010; 193:177-89. [PMID: 20971913 DOI: 10.1128/jb.00895-10] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Pseudomonas fluorescens Q8r1-96 represents a group of rhizosphere strains responsible for the suppressiveness of agricultural soils to take-all disease of wheat. It produces the antibiotic 2,4-diacetylphloroglucinol and aggressively colonizes the roots of cereal crops. In this study, we analyzed the genome of Q8r1-96 and identified a type III protein secretion system (T3SS) gene cluster that has overall organization similar to that of the T3SS gene cluster of the plant pathogen Pseudomonas syringae. We also screened a collection of 30 closely related P. fluorescens strains and detected the T3SS genes in all but one of them. The Q8r1-96 genome contained ropAA and ropM type III effector genes, which are orthologs of the P. syringae effector genes hopAA1-1 and hopM1, as well as a novel type III effector gene designated ropB. These type III effector genes encoded proteins that were secreted in culture and injected into plant cells by both P. syringae and Q8r1-96 T3SSs. The Q8r1-96 T3SS was expressed in the rhizosphere, but mutants lacking a functional T3SS were not altered in their rhizosphere competence. The Q8r1-96 type III effectors RopAA, RopB, and RopM were capable of suppressing the hypersensitive response and production of reactive oxygen species, two plant immune responses.
Collapse
|
19
|
Ebbs SD, Kosma DK, Nielson EH, Machingura M, Baker AJM, Woodrow IE. Nitrogen supply and cyanide concentration influence the enrichment of nitrogen from cyanide in wheat (Triticum aestivum L.) and sorghum (Sorghum bicolor L.). PLANT, CELL & ENVIRONMENT 2010; 33:1152-60. [PMID: 20199620 DOI: 10.1111/j.1365-3040.2010.02136.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Cyanide assimilation by the beta-cyanoalanine pathway produces asparagine, aspartate and ammonium, allowing cyanide to serve as alternate or supplemental source of nitrogen. Experiments with wheat and sorghum examined the enrichment of (15)N from cyanide as a function of external cyanide concentration in the presence or absence of nitrate and/or ammonium. Cyanogenic nitrogen became enriched in plant tissues following exposure to (15)N-cyanide concentrations from 5 to 200 microm, but when exposure occurred in the absence of nitrate and ammonium, (15)N enrichment increased significantly in sorghum shoots at solution cyanide concentrations of > or =50 microm and in wheat roots at 200 microm cyanide. In an experiment with sorghum using (13)C(15)N, there was also a significant difference in the tissue (13)C:(15)N ratio, suggestive of differential metabolism and transport of carbon and nitrogen under nitrogen-free conditions. A reciprocal (15)N labelling study using KC(15)N and (15)NH(4)(+) and wheat demonstrated an interaction between cyanide and ammonium in roots in which increasing solution ammonium concentrations decreased the enrichment from 100 microm cyanide. In contrast, with increasing solution cyanide concentrations there was an increase in the enrichment from ammonium. The results suggest increased transport and assimilation of cyanide in response to decreased nitrogen supply and perhaps to ammonium supply.
Collapse
Affiliation(s)
- Stephen D Ebbs
- Department of Plant Biology and Center for Ecology, Southern Illinois University Carbondale, Carbondale, Illinois 62901-6509, USA.
| | | | | | | | | | | |
Collapse
|
20
|
Regulatory roles of the bacterial nitrogen-related phosphotransferase system. Trends Microbiol 2010; 18:205-14. [DOI: 10.1016/j.tim.2010.02.003] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Revised: 01/27/2010] [Accepted: 02/08/2010] [Indexed: 11/20/2022]
|
21
|
Chauhan P, Nautiyal C. ThepurBgene controls rhizosphere colonization byPantoea agglomerans. Lett Appl Microbiol 2010; 50:205-10. [DOI: 10.1111/j.1472-765x.2009.02779.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
22
|
Temperature-dependent expression of phzM and its regulatory genes lasI and ptsP in rhizosphere isolate Pseudomonas sp. strain M18. Appl Environ Microbiol 2009; 75:6568-80. [PMID: 19717631 DOI: 10.1128/aem.01148-09] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas sp. strain M18, an effective biological control agent isolated from the melon rhizosphere, has a genetic background similar to that of the opportunistic human pathogen Pseudomonas aeruginosa PAO1. However, the predominant phenazine produced by strain M18 is phenazine-1-carboxylic acid (PCA) rather than pyocyanin (PYO); the quantitative ratio of PCA to PYO is 105 to 1 at 28 degrees C in strain M18, while the ratio is 1 to 2 at 37 degrees C in strain PAO1. We first provided evidence that the differential production of the two phenazines in strains M18 and PAO1 is related to the temperature-dependent and strain-specific expression patterns of phzM, a gene involved in the conversion of PCA to PYO. Transcriptional levels of phzM were measured by quantitative real-time PCR, and the activities of both transcriptional and translational phzM'-'lacZ fusions were determined in strains M18 and PAO1, respectively. Using lasI::Gm and ptsP::Gm inactivation M18 mutants, we further show that expression of the phzM gene is positively regulated by the quorum-sensing protein LasI and negatively regulated by the phosphoenolpyruvate phosphotransferase protein PtsP. Surprisingly, the lasI and ptsP regulatory genes were also expressed in a temperature-dependent and strain-specific manner. The differential production of the phenazines PCA and PYO by strains M18 and PAO1 may be a consequence of selective pressure imposed on P. aeruginosa PAO1 and its relative M18 in the two different niches over a long evolutionary process.
Collapse
|
23
|
Couillerot O, Prigent-Combaret C, Caballero-Mellado J, Moënne-Loccoz Y. Pseudomonas fluorescensand closely-related fluorescent pseudomonads as biocontrol agents of soil-borne phytopathogens. Lett Appl Microbiol 2009; 48:505-12. [DOI: 10.1111/j.1472-765x.2009.02566.x] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Nautiyal CS, Srivastava S, Chauhan PS. Rhizosphere Colonization: Molecular Determinants from Plant-Microbe Coexistence Perspective. SOIL BIOLOGY 2008. [DOI: 10.1007/978-3-540-75575-3_4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
25
|
Mercado-Blanco J, Bakker PAHM. Interactions between plants and beneficial Pseudomonas spp.: exploiting bacterial traits for crop protection. Antonie Van Leeuwenhoek 2007; 92:367-89. [PMID: 17588129 DOI: 10.1007/s10482-007-9167-1] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 03/12/2007] [Indexed: 11/29/2022]
Abstract
Specific strains of fluorescent Pseudomonas spp. inhabit the environment surrounding plant roots and some even the root interior. Introducing such bacterial strains to plant roots can lead to increased plant growth, usually due to suppression of plant pathogenic microorganisms. We review the modes of action and traits of these beneficial Pseudomonas bacteria involved in disease suppression. The complex regulation of biological control traits in relation to the functioning in the root environment is discussed. Understanding the complexity of the interactions is instrumental in the exploitation of beneficial Pseudomonas spp. in controlling plant diseases.
Collapse
Affiliation(s)
- Jesús Mercado-Blanco
- Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Apartado 4084, 14080 Cordoba, Spain.
| | | |
Collapse
|