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Janse van Rensburg H, Stengele K, Schlaeppi K. Understanding plant responsiveness to microbiome feedbacks. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102603. [PMID: 39024858 DOI: 10.1016/j.pbi.2024.102603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 06/28/2024] [Accepted: 06/30/2024] [Indexed: 07/20/2024]
Abstract
Plant microbiome interactions are bidirectional with processes leading to microbiome assembly and processes leading to effects on plants, so called microbiome feedbacks. With belowground focus we systematically decomposed both of these directions into plant and (root and rhizosphere) microbiome components to identify methodological challenges and research priorities. We found that the bidirectionality of plant microbiome interactions presents a challenge for genetic studies. Establishing causality is particularly difficult when a plant mutant has both, an altered phenotype and an altered microbiome. Is the mutation directly affecting the microbiome (e.g., through root exudates), which then causes an altered phenotype of the plant and/or is the altered microbiome the consequence of the mutation altering the plant's phenotype (e.g., root architecture)? Here, we put forward that feedback experiments allow to separate cause and effect and furthermore, they are useful for investigating plant interactions with complex microbiomes in natural soils. They especially allow to investigate the plant genetic basis how plants respond to soil microbiomes and we stress that such microbiome feedbacks are understudied compared to the mechanisms contributing to microbiome assembly. Thinking towards application, this may allow to develop crops with both abilities to assemble a beneficial microbiome and to actively exploit its feedbacks.
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Affiliation(s)
| | - Katja Stengele
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Klaus Schlaeppi
- Department of Environmental Sciences, University of Basel, Basel, Switzerland.
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2
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Backman T, Latorre SM, Symeonidi E, Muszyński A, Bleak E, Eads L, Martinez-Koury PI, Som S, Hawks A, Gloss AD, Belnap DM, Manuel AM, Deutschbauer AM, Bergelson J, Azadi P, Burbano HA, Karasov TL. A phage tail-like bacteriocin suppresses competitors in metapopulations of pathogenic bacteria. Science 2024; 384:eado0713. [PMID: 38870284 DOI: 10.1126/science.ado0713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 04/24/2024] [Indexed: 06/15/2024]
Abstract
Bacteria can repurpose their own bacteriophage viruses (phage) to kill competing bacteria. Phage-derived elements are frequently strain specific in their killing activity, although there is limited evidence that this specificity drives bacterial population dynamics. Here, we identified intact phage and their derived elements in a metapopulation of wild plant-associated Pseudomonas genomes. We discovered that the most abundant viral cluster encodes a phage remnant resembling a phage tail called a tailocin, which bacteria have co-opted to kill bacterial competitors. Each pathogenic Pseudomonas strain carries one of a few distinct tailocin variants that target the variable polysaccharides in the outer membrane of co-occurring pathogenic Pseudomonas strains. Analysis of herbarium samples from the past 170 years revealed that the same tailocin and bacterial receptor variants have persisted in Pseudomonas populations. These results suggest that tailocin genetic diversity can be mined to develop targeted "tailocin cocktails" for microbial control.
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Affiliation(s)
- Talia Backman
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Sergio M Latorre
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
- Research Group for Ancient Genomics and Evolution, Department of Molecular Biology, Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Efthymia Symeonidi
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Ella Bleak
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Lauren Eads
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | | | - Sarita Som
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Aubrey Hawks
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Andrew D Gloss
- Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - David M Belnap
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA
| | - Allison M Manuel
- Mass Spectrometry and Proteomics Core, The University of Utah, Salt Lake City, UT 84112, USA
| | - Adam M Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Joy Bergelson
- Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Hernán A Burbano
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
- Research Group for Ancient Genomics and Evolution, Department of Molecular Biology, Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Talia L Karasov
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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Lucas-Elío P, ElAlami T, Martínez A, Sanchez-Amat A. Marinomonas mediterranea synthesizes an R-type bacteriocin. Appl Environ Microbiol 2024; 90:e0127323. [PMID: 38169292 PMCID: PMC10870725 DOI: 10.1128/aem.01273-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/17/2023] [Indexed: 01/05/2024] Open
Abstract
Prophages integrated into bacterial genomes can become cryptic or defective prophages, which may evolve to provide various traits to bacterial cells. Previous research on Marinomonas mediterranea MMB-1 demonstrated the production of defective particles. In this study, an analysis of the genomes of three different strains (MMB-1, MMB-2, and MMB-3) revealed the presence of a region named MEDPRO1, spanning approximately 52 kb, coding for a defective prophage in strains MMB-1 and MMB-2. This prophage seems to have been lost in strain MMB-3, possibly due to the presence of spacers recognizing this region in an I-F CRISPR array in this strain. However, all three strains produce remarkably similar defective particles. Using strain MMB-1 as a model, mass spectrometry analyses indicated that the structural proteins of the defective particles are encoded by a second defective prophage situated within the MEDPRO2 region, spanning approximately 13 kb. This finding was further validated through the deletion of this second defective prophage. Genomic region analyses and the detection of antimicrobial activity of the defective prophage against other Marinomonas species suggest that it is an R-type bacteriocin. Marinomonas mediterranea synthesizes antimicrobial proteins with lysine oxidase activity, and the synthesis of an R-type bacteriocin constitutes an additional mechanism in microbial competition for the colonization of habitats such as the surface of marine plants.IMPORTANCEThe interactions between bacterial strains inhabiting the same environment determine the final composition of the microbiome. In this study, it is shown that some extracellular defective phage particles previously observed in Marinomonas mediterranea are in fact R-type bacteriocins showing antimicrobial activity against other Marinomonas strains. The operon coding for the R-type bacteriocin has been identified.
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Affiliation(s)
- Patricia Lucas-Elío
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
| | - Tarik ElAlami
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
| | - Alicia Martínez
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
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4
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Ishii T, Tsuchida N, Hemelda NM, Saito K, Bao J, Watanabe M, Toyoda A, Matsubara T, Sato M, Toyooka K, Ishihama N, Shirasu K, Matsui H, Toyoda K, Ichinose Y, Hayashi T, Kawaguchi A, Noutoshi Y. Rhizoviticin is an alphaproteobacterial tailocin that mediates biocontrol of grapevine crown gall disease. THE ISME JOURNAL 2024; 18:wrad003. [PMID: 38365227 PMCID: PMC10811719 DOI: 10.1093/ismejo/wrad003] [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: 07/25/2023] [Revised: 10/27/2023] [Accepted: 11/06/2023] [Indexed: 02/18/2024]
Abstract
Tailocins are headless phage tail structures that mediate interbacterial antagonism. Although the prototypical tailocins, R- and F-pyocins, in Pseudomonas aeruginosa, and other predominantly R-type tailocins have been studied, their presence in Alphaproteobacteria remains unexplored. Here, we report the first alphaproteobacterial F-type tailocin, named rhizoviticin, as a determinant of the biocontrol activity of Allorhizobium vitis VAR03-1 against crown gall. Rhizoviticin is encoded by a chimeric prophage genome, one providing transcriptional regulators and the other contributing to tail formation and cell lysis, but lacking head formation genes. The rhizoviticin genome retains a nearly intact early phage region containing an integrase remnant and replication-related genes critical for downstream gene transcription, suggesting an ongoing transition of this locus from a prophage to a tailocin-coding region. Rhizoviticin is responsible for the most antagonistic activity in VAR03-1 culture supernatant against pathogenic A. vitis strain, and rhizoviticin deficiency resulted in a significant reduction in the antitumorigenic activity in planta. We identified the rhizoviticin-coding locus in eight additional A. vitis strains from diverse geographical locations, highlighting a unique survival strategy of certain Rhizobiales bacteria in the rhizosphere. These findings advance our understanding of the evolutionary dynamics of tailocins and provide a scientific foundation for employing rhizoviticin-producing strains in plant disease control.
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Affiliation(s)
- Tomoya Ishii
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Natsuki Tsuchida
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
- Present address: Division of Biological Science, Nara Institute of Science and Technology (NAIST), Ikoma, Nara 630-0192, Japan
| | - Niarsi Merry Hemelda
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Department of Biology, University of Indonesia, Depok 16424, Indonesia
| | - Kirara Saito
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Present address: Kyushu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, Miyakonojo, Miyazaki 885-0091, Japan
| | - Jiyuan Bao
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Megumi Watanabe
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Takehiro Matsubara
- Okayama University Hospital Biobank, Okayama University Hospital, Okayama 700-8558, Japan
| | - Mayuko Sato
- Mass Spectrometry and Microscopy Unit, Technology Platform Division, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Kiminori Toyooka
- Mass Spectrometry and Microscopy Unit, Technology Platform Division, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Nobuaki Ishihama
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
| | - Ken Shirasu
- Plant Immunity Research Group, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan
- Graduate School of Science, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hidenori Matsui
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Kazuhiro Toyoda
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Yuki Ichinose
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Akira Kawaguchi
- Western Region Agricultural Research Center (WARC), National Agricultural and Food Research Organization (NARO), Fukuyama, Hiroshima 721-8514, Japan
| | - Yoshiteru Noutoshi
- Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
- Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan
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5
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Booth SC, Smith WPJ, Foster KR. The evolution of short- and long-range weapons for bacterial competition. Nat Ecol Evol 2023; 7:2080-2091. [PMID: 38036633 PMCID: PMC10697841 DOI: 10.1038/s41559-023-02234-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 09/22/2023] [Indexed: 12/02/2023]
Abstract
Bacteria possess a diverse range of mechanisms for inhibiting competitors, including bacteriocins, tailocins, type VI secretion systems and contact-dependent inhibition (CDI). Why bacteria have evolved such a wide array of weapon systems remains a mystery. Here we develop an agent-based model to compare short-range weapons that require cell-cell contact, with long-range weapons that rely on diffusion. Our model predicts that contact weapons are useful when an attacking strain is outnumbered, facilitating invasion and establishment. By contrast, ranged weapons tend to be effective only when attackers are abundant. We test our predictions with the opportunistic pathogen Pseudomonas aeruginosa, which naturally carries multiple weapons, including CDI and diffusing tailocins. As predicted, short-range CDI can function at low and high frequencies, while long-range tailocins require high frequency and cell density to function effectively. Head-to-head competition experiments with the two weapon types further support our predictions: a tailocin attacker defeats CDI only when it is numerically dominant, but then we find it can be devastating. Finally, we show that the two weapons work well together when one strain employs both. We conclude that short- and long-range weapons serve different functions and allow bacteria to fight both as individuals and as a group.
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Affiliation(s)
- Sean C Booth
- Department of Biology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - William P J Smith
- Department of Biology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
- Division of Evolution, Infection and Genomics, University of Manchester, Manchester, UK
| | - Kevin R Foster
- Department of Biology, University of Oxford, Oxford, UK.
- Department of Biochemistry, University of Oxford, Oxford, UK.
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Heiman CM, Vacheron J, Keel C. Evolutionary and ecological role of extracellular contractile injection systems: from threat to weapon. Front Microbiol 2023; 14:1264877. [PMID: 37886057 PMCID: PMC10598620 DOI: 10.3389/fmicb.2023.1264877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Contractile injection systems (CISs) are phage tail-related structures that are encoded in many bacterial genomes. These devices encompass the cell-based type VI secretion systems (T6SSs) as well as extracellular CISs (eCISs). The eCISs comprise the R-tailocins produced by various bacterial species as well as related phage tail-like structures such as the antifeeding prophages (Afps) of Serratia entomophila, the Photorhabdus virulence cassettes (PVCs), and the metamorphosis-associated contractile structures (MACs) of Pseudoalteromonas luteoviolacea. These contractile structures are released into the extracellular environment upon suicidal lysis of the producer cell and play important roles in bacterial ecology and evolution. In this review, we specifically portray the eCISs with a focus on the R-tailocins, sketch the history of their discovery and provide insights into their evolution within the bacterial host, their structures and how they are assembled and released. We then highlight ecological and evolutionary roles of eCISs and conceptualize how they can influence and shape bacterial communities. Finally, we point to their potential for biotechnological applications in medicine and agriculture.
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Affiliation(s)
- Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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7
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Villar-Moreno R, Tienda S, Gutiérrez-Barranquero JA, Carrión VJ, de Vicente A, Cazorla FM, Arrebola E. Interplay between rhizospheric Pseudomonas chlororaphis strains lays the basis for beneficial bacterial consortia. FRONTIERS IN PLANT SCIENCE 2022; 13:1063182. [PMID: 36589057 PMCID: PMC9797978 DOI: 10.3389/fpls.2022.1063182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Pseudomonas chlororaphis (Pc) representatives are found as part of the rhizosphere-associated microbiome, and different rhizospheric Pc strains frequently perform beneficial activities for the plant. In this study we described the interactions between the rhizospheric Pc strains PCL1601, PCL1606 and PCL1607 with a focus on their effects on root performance. Differences among the three rhizospheric Pc strains selected were first observed in phylogenetic studies and confirmed by genome analysis, which showed variation in the presence of genes related to antifungal compounds or siderophore production, among others. Observation of the interactions among these strains under lab conditions revealed that PCL1606 has a better adaptation to environments rich in nutrients, and forms biofilms. Interaction experiments on plant roots confirmed the role of the different phenotypes in their lifestyle. The PCL1606 strain was the best adapted to the habitat of avocado roots, and PCL1607 was the least, and disappeared from the plant root scenario after a few days of interaction. These results confirm that 2 out 3 rhizospheric Pc strains were fully compatible (PCL1601 and PCL1606), efficiently colonizing avocado roots and showing biocontrol activity against the fungal pathogen Rosellinia necatrix. The third strain (PCL1607) has colonizing abilities when it is alone on the root but displayed difficulties under the competition scenario, and did not cause deleterious effects on the other Pc competitors when they were present. These results suggest that strains PCL1601 and PCL1606 are very well adapted to the avocado root environment and could constitute a basis for constructing a more complex beneficial microbial synthetic community associated with avocado plant roots.
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Affiliation(s)
- Rafael Villar-Moreno
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Sandra Tienda
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Jose A. Gutiérrez-Barranquero
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Víctor J. Carrión
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Antonio de Vicente
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Francisco M. Cazorla
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Eva Arrebola
- Mango and Avocado Microbiology Group, Department of Microbiology, Faculty of Sciences, University of Málaga, Málaga, Spain
- Department of Microbiology and Plant Protection, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
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Sun W, Liang X, Zhu C, Xu Y, Ding Y, Huang YP. Regulation of maltocin synthesis in Stenotrophomonas maltophilia by positive and negative regulators. Res Microbiol 2022; 173:103956. [DOI: 10.1016/j.resmic.2022.103956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/25/2022] [Accepted: 05/05/2022] [Indexed: 11/30/2022]
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9
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Boak EN, Kirolos S, Pan H, Pierson LS, Pierson EA. The Type VI Secretion Systems in Plant-Beneficial Bacteria Modulate Prokaryotic and Eukaryotic Interactions in the Rhizosphere. Front Microbiol 2022; 13:843092. [PMID: 35464916 PMCID: PMC9022076 DOI: 10.3389/fmicb.2022.843092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 03/04/2022] [Indexed: 01/15/2023] Open
Abstract
Rhizosphere colonizing plant growth promoting bacteria (PGPB) increase their competitiveness by producing diffusible toxic secondary metabolites, which inhibit competitors and deter predators. Many PGPB also have one or more Type VI Secretion System (T6SS), for the delivery of weapons directly into prokaryotic and eukaryotic cells. Studied predominantly in human and plant pathogens as a virulence mechanism for the delivery of effector proteins, the function of T6SS for PGPB in the rhizosphere niche is poorly understood. We utilized a collection of Pseudomonas chlororaphis 30-84 mutants deficient in one or both of its two T6SS and/or secondary metabolite production to examine the relative importance of each T6SS in rhizosphere competence, bacterial competition, and protection from bacterivores. A mutant deficient in both T6SS was less persistent than wild type in the rhizosphere. Both T6SS contributed to competitiveness against other PGPB or plant pathogenic strains not affected by secondary metabolite production, but only T6SS-2 was effective against strains lacking their own T6SS. Having at least one T6SS was also essential for protection from predation by several eukaryotic bacterivores. In contrast to diffusible weapons that may not be produced at low cell density, T6SS afford rhizobacteria an additional, more immediate line of defense against competitors and predators.
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Affiliation(s)
- Emily N Boak
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States
| | - Sara Kirolos
- Department of Biology, Texas A&M University, College Station, TX, United States
| | - Huiqiao Pan
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States.,Department of Embryology, Carnegie Institution for Science, Baltimore, MD, United States
| | - Leland S Pierson
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
| | - Elizabeth A Pierson
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, United States.,Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, United States
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10
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Antimicrobial Weapons of Pseudomonas aeruginosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:223-256. [DOI: 10.1007/978-3-031-08491-1_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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11
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Snopková K, Dufková K, Chamrád I, Lenobel R, Čejková D, Kosina M, Hrala M, Holá V, Sedláček I, Šmajs D. Pyocin-mediated antagonistic interactions in Pseudomonas spp. isolated in James Ross Island, Antarctica. Environ Microbiol 2021; 24:1294-1307. [PMID: 34735036 DOI: 10.1111/1462-2920.15809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/15/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022]
Abstract
Interactions within bacterial communities are frequently mediated by the production of antimicrobial agents. Despite the increasing interest in research of new antimicrobials, studies describing antagonistic interactions among cold-adapted microorganisms are still rare. Our study assessed the antimicrobial interactions of 36 Antarctic Pseudomonas spp. and described the genetic background of these interactions in selected strains. The overall bacteriocinogeny was greater compared to mesophilic Pseudomonas non-aeruginosa species. R-type tailocins were detected on transmission electron micrographs in 16 strains (44.4%); phylogenetic analysis of the corresponding gene clusters revealed that the P. prosekii CCM 8878 tailocin was related to the Rp3 group, whereas the tailocin in Pseudomonas sp. CCM 8880 to the Rp4 group. Soluble antimicrobials were produced by eight strains (22.-2%); gene mining found pyocin L homologues in the genomes of P. prosekii CCM 8881 and CCM 8879 and pyocin S9-like homologues in P. prosekii CCM 8881 and Pseudomonas sp. CCM 8880. Analysis of secretomes confirmed the production of all S- and L-type pyocin genes. Our results suggest that bacteriocin-based inhibition plays an important role in interactions among Antarctic soil bacteria, and these native, cold-adapted microorganisms could be a promising source of new antimicrobials.
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Affiliation(s)
- Kateřina Snopková
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Kristýna Dufková
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Ivo Chamrád
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 241/27, Olomouc-Holice, 779 00, Czech Republic
| | - René Lenobel
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 241/27, Olomouc-Holice, 779 00, Czech Republic
| | - Darina Čejková
- Veterinary Research Institute, Hudcova 296/70, Brno, 621 00, Czech Republic
| | - Marcel Kosina
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Matěj Hrala
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Veronika Holá
- Faculty of Medicine, Institute for Microbiology, Masaryk University and St. Anne's University Hospital Brno, Pekařská 664/53, Brno, 656 91, Czech Republic
| | - Ivo Sedláček
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
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12
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Carim S, Azadeh AL, Kazakov AE, Price MN, Walian PJ, Lui LM, Nielsen TN, Chakraborty R, Deutschbauer AM, Mutalik VK, Arkin AP. Systematic discovery of pseudomonad genetic factors involved in sensitivity to tailocins. THE ISME JOURNAL 2021; 15:2289-2305. [PMID: 33649553 PMCID: PMC8319346 DOI: 10.1038/s41396-021-00921-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/14/2021] [Accepted: 02/01/2021] [Indexed: 12/13/2022]
Abstract
Tailocins are bactericidal protein complexes produced by a wide variety of bacteria that kill closely related strains and may play a role in microbial community structure. Thanks to their high specificity, tailocins have been proposed as precision antibacterial agents for therapeutic applications. Compared to tailed phages, with whom they share an evolutionary and morphological relationship, bacterially produced tailocins kill their host upon production but producing strains display resistance to self-intoxication. Though lipopolysaccharide (LPS) has been shown to act as a receptor for tailocins, the breadth of factors involved in tailocin sensitivity, and the mechanisms behind resistance to self-intoxication, remain unclear. Here, we employed genome-wide screens in four non-model pseudomonads to identify mutants with altered fitness in the presence of tailocins produced by closely related pseudomonads. Our mutant screens identified O-antigen composition and display as most important in defining sensitivity to our tailocins. In addition, the screens suggest LPS thinning as a mechanism by which resistant strains can become more sensitive to tailocins. We validate many of these novel findings, and extend these observations of tailocin sensitivity to 130 genome-sequenced pseudomonads. This work offers insights into tailocin-bacteria interactions, informing the potential use of tailocins in microbiome manipulation and antibacterial therapy.
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Affiliation(s)
- Sean Carim
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Ashley L Azadeh
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Alexey E Kazakov
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Morgan N Price
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Peter J Walian
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Lauren M Lui
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Torben N Nielsen
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Romy Chakraborty
- Climate and Ecosystem Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vivek K Mutalik
- Innovative Genomics Institute, University of California, Berkeley, CA, USA.
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Adam P Arkin
- Innovative Genomics Institute, University of California, Berkeley, CA, USA.
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Bioengineering, University of California, Berkeley, CA, USA.
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13
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Bertani I, Zampieri E, Bez C, Volante A, Venturi V, Monaco S. Isolation and Characterization of Pseudomonas chlororaphis Strain ST9; Rhizomicrobiota and in Planta Studies. PLANTS 2021; 10:plants10071466. [PMID: 34371669 PMCID: PMC8309335 DOI: 10.3390/plants10071466] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/12/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
The development of biotechnologies based on beneficial microorganisms for improving soil fertility and crop yields could help to address many current agriculture challenges, such as food security, climate change, pest control, soil depletion while decreasing the use of chemical fertilizers and pesticides. Plant growth-promoting (PGP) microbes can be used as probiotics in order to increase plant tolerance/resistance to abiotic/biotic stresses and in this context strains belonging to the Pseudomonas chlororaphis group have shown to have potential as PGP candidates. In this study a new P. chlororaphis isolate is reported and tested for (i) in vitro PGP features, (ii) whole-genome sequence analysis, and (iii) its effects on the rhizosphere microbiota composition, plant growth, and different plant genes expression levels in greenhouse experiments. Results showed that P. chlororaphis ST9 is an efficient rice root colonizer which integrates into the plant resident-microbiota and affects the expression of several plant genes. The potential use of this P. chlororaphis strain as a plant probiotic is discussed.
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Affiliation(s)
- Iris Bertani
- International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy; (I.B.); (C.B.)
| | - Elisa Zampieri
- Council for Agricultural Research and Economics-Research Centre for Cereal and Industrial Crops, s.s. 11 to Torino, km 2.5, 13100 Vercelli, Italy; (E.Z.); (A.V.)
- Institute for Sustainable Plant Protection, National Research Council, Strada delle Cacce 73, 10135 Turin, Italy
| | - Cristina Bez
- International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy; (I.B.); (C.B.)
| | - Andrea Volante
- Council for Agricultural Research and Economics-Research Centre for Cereal and Industrial Crops, s.s. 11 to Torino, km 2.5, 13100 Vercelli, Italy; (E.Z.); (A.V.)
- Council for Agricultural Research and Economics-Research Centre for Vegetable and Ornamental Crops, Corso Inglesi 508, 18038 Sanremo, Italy
| | - Vittorio Venturi
- International Centre for Genetic Engineering and Biotechnology, 34149 Trieste, Italy; (I.B.); (C.B.)
- Correspondence: (V.V.); (S.M.)
| | - Stefano Monaco
- Council for Agricultural Research and Economics-Research Centre for Cereal and Industrial Crops, s.s. 11 to Torino, km 2.5, 13100 Vercelli, Italy; (E.Z.); (A.V.)
- Correspondence: (V.V.); (S.M.)
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14
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Vacheron J, Heiman CM, Keel C. Live cell dynamics of production, explosive release and killing activity of phage tail-like weapons for Pseudomonas kin exclusion. Commun Biol 2021; 4:87. [PMID: 33469108 PMCID: PMC7815802 DOI: 10.1038/s42003-020-01581-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 12/07/2020] [Indexed: 01/29/2023] Open
Abstract
Interference competition among bacteria requires a highly specialized, narrow-spectrum weaponry when targeting closely-related competitors while sparing individuals from the same clonal population. Here we investigated mechanisms by which environmentally important Pseudomonas bacteria with plant-beneficial activity perform kin interference competition. We show that killing between phylogenetically closely-related strains involves contractile phage tail-like devices called R-tailocins that puncture target cell membranes. Using live-cell imaging, we evidence that R-tailocins are produced at the cell center, transported to the cell poles and ejected by explosive cell lysis. This enables their dispersal over several tens of micrometers to reach targeted cells. We visualize R-tailocin-mediated competition dynamics between closely-related Pseudomonas strains at the single-cell level, both in non-induced condition and upon artificial induction. We document the fatal impact of cellular self-sacrifice coupled to deployment of phage tail-like weaponry in the microenvironment of kin bacterial competitors, emphasizing the necessity for microscale assessment of microbial competitions.
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Affiliation(s)
- Jordan Vacheron
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Clara Margot Heiman
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland
| | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, CH-1015, Lausanne, Switzerland.
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15
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Zboralski A, Filion M. Genetic factors involved in rhizosphere colonization by phytobeneficial Pseudomonas spp. Comput Struct Biotechnol J 2020; 18:3539-3554. [PMID: 33304453 PMCID: PMC7711191 DOI: 10.1016/j.csbj.2020.11.025] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 12/13/2022] Open
Abstract
Plant growth-promoting rhizobacteria (PGPR) actively colonize the soil portion under the influence of plant roots, called the rhizosphere. Many plant-beneficial Pseudomonas spp. have been characterized as PGPR. They are ubiquitous rod-shaped motile Gram-negative bacteria displaying a high metabolic versatility. Their capacity to protect plants from pathogens and improve plant growth closely depends on their rhizosphere colonization abilities. Various molecular and cellular mechanisms are involved in this complex process, such as chemotaxis, biofilm formation, secondary metabolites biosynthesis, metabolic versatility, and evasion of plant immunity. The burst in Pseudomonas spp. genome sequencing in recent years has been crucial to better understand how they colonize the rhizosphere. In this review, we discuss the recent advances regarding these mechanisms and the underlying bacterial genetic factors required for successful rhizosphere colonization.
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Affiliation(s)
- Antoine Zboralski
- Department of Biology, Université de Moncton, Moncton, NB E1A 3E9, Canada
| | - Martin Filion
- Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada
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16
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Thappeta KRV, Ciezki K, Morales-Soto N, Wesener S, Goodrich-Blair H, Stock SP, Forst S. R-type bacteriocins of Xenorhabdus bovienii determine the outcome of interspecies competition in a natural host environment. MICROBIOLOGY-SGM 2020; 166:1074-1087. [PMID: 33064635 DOI: 10.1099/mic.0.000981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Xenorhabdus species are bacterial symbionts of Steinernema nematodes and pathogens of susceptible insects. Different species of Steinernema nematodes carrying specific species of Xenorhabdus can invade the same insect, thereby setting up competition for nutrients within the insect environment. While Xenorhabdus species produce both diverse antibiotic compounds and prophage-derived R-type bacteriocins (xenorhabdicins), the functions of these molecules during competition in a host are not well understood. Xenorhabdus bovienii (Xb-Sj), the symbiont of Steinernema jollieti, possesses a remnant P2-like phage tail cluster, xbp1, that encodes genes for xenorhabdicin production. We show that inactivation of either tail sheath (xbpS1) or tail fibre (xbpH1) genes eliminated xenorhabdicin production. Preparations of Xb-Sj xenorhabdicin displayed a narrow spectrum of activity towards other Xenorhabdus and Photorhabdus species. One species, Xenorhabdus szentirmaii (Xsz-Sr), was highly sensitive to Xb-Sj xenorhabdicin but did not produce xenorhabdicin that was active against Xb-Sj. Instead, Xsz-Sr produced high-level antibiotic activity against Xb-Sj when grown in complex medium and lower levels when grown in defined medium (Grace's medium). Conversely, Xb-Sj did not produce detectable levels of antibiotic activity against Xsz-Sr. To study the relative contributions of Xb-Sj xenorhabdicin and Xsz-Sr antibiotics in interspecies competition in which the respective Xenorhabdus species produce antagonistic activities against each other, we co-inoculated cultures with both Xenorhabdus species. In both types of media Xsz-Sr outcompeted Xb-Sj, suggesting that antibiotics produced by Xsz-Sr determined the outcome of the competition. In contrast, Xb-Sj outcompeted Xsz-Sr in competitions performed by co-injection in the insect Manduca sexta, while in competition with the xenorhabdicin-deficient strain (Xb-Sj:S1), Xsz-Sr was dominant. Thus, xenorhabdicin was required for Xb-Sj to outcompete Xsz-Sr in a natural host environment. These results highlight the importance of studying the role of antagonistic compounds under natural biological conditions.
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Affiliation(s)
- Kishore Reddy Venkata Thappeta
- University of Wisconsin, Milwaukee, WI, USA.,Singapore Institute of Food and Biotechnology Innovation (SIFBI), A*STAR, Singapore
| | - Kristin Ciezki
- Aurora Health Care, Milwaukee, WI, USA.,University of Wisconsin, Milwaukee, WI, USA
| | - Nydia Morales-Soto
- Eck Institute for Global Health, University of Notre Dame, IN, USA.,University of Wisconsin, Milwaukee, WI, USA
| | | | - Heidi Goodrich-Blair
- University of Tennessee, Knoxville, TN, USA.,University of Wisconsin, Madison, WI, USA
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17
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Rooney WM, Chai R, Milner JJ, Walker D. Bacteriocins Targeting Gram-Negative Phytopathogenic Bacteria: Plantibiotics of the Future. Front Microbiol 2020; 11:575981. [PMID: 33042091 PMCID: PMC7530242 DOI: 10.3389/fmicb.2020.575981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/25/2020] [Indexed: 12/12/2022] Open
Abstract
Gram-negative phytopathogenic bacteria are a significant threat to food crops. These microbial invaders are responsible for a plethora of plant diseases and can be responsible for devastating losses in crops such as tomatoes, peppers, potatoes, olives, and rice. Current disease management strategies to mitigate yield losses involve the application of chemicals which are often harmful to both human health and the environment. Bacteriocins are small proteinaceous antibiotics produced by bacteria to kill closely related bacteria and thereby establish dominance within a niche. They potentially represent a safer alternative to chemicals when used in the field. Bacteriocins typically show a high degree of selectivity toward their targets with no off-target effects. This review outlines the current state of research on bacteriocins active against Gram-negative phytopathogenic bacteria. Furthermore, we will examine the feasibility of weaponizing bacteriocins for use as a treatment for bacterial plant diseases.
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Affiliation(s)
- William M. Rooney
- Plant Science Group, School of Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Ray Chai
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Joel J. Milner
- Plant Science Group, School of Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Daniel Walker
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
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18
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Tienda S, Vida C, Lagendijk E, de Weert S, Linares I, González-Fernández J, Guirado E, de Vicente A, Cazorla FM. Soil Application of a Formulated Biocontrol Rhizobacterium, Pseudomonas chlororaphis PCL1606, Induces Soil Suppressiveness by Impacting Specific Microbial Communities. Front Microbiol 2020; 11:1874. [PMID: 32849458 PMCID: PMC7426498 DOI: 10.3389/fmicb.2020.01874] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/16/2020] [Indexed: 12/14/2022] Open
Abstract
Biocontrol bacteria can be used for plant protection against some plant diseases. Pseudomonas chlororaphis PCL1606 (PcPCL1606) is a model bacterium isolated from the avocado rhizosphere with strong antifungal antagonism mediated by the production of 2-hexyl, 5-propil resorcinol (HPR). Additionally, PcPCL1606 has biological control against different soil-borne fungal pathogens, including the causal agent of the white root rot of many woody crops and avocado in the Mediterranean area, Rosellinia necatrix. The objective of this study was to assess whether the semicommercial application of PcPCL1606 to soil can potentially affect avocado soil and rhizosphere microbial communities and their activities in natural conditions and under R. necatrix infection. To test the putative effects of PcPCL1606 on soil eukaryotic and prokaryotic communities, a formulated PcPCL1606 was prepared and applied to the soil of avocado plants growing in mesocosm experiments, and the communities were analyzed by using 16S/ITS metagenomics. PcPCL1606 survived until the end of the experiments. The effect of PcPCL1606 application on prokaryotic communities in soil and rhizosphere samples from natural soil was not detectable, and very minor changes were observed in eukaryotic communities. In the infested soils, the presence of R. necatrix strongly impacted the soil and rhizosphere microbial communities. However, after PcPCL1606 was applied to soil infested with R. necatrix, the prokaryotic community reacted by increasing the relative abundance of few families with protective features against fungal soilborne pathogens and organic matter decomposition (Chitinophagaceae, Cytophagaceae), but no new prokaryotic families were detected. The treatment of PcPCL1606 impacted the fungal profile, which strongly reduced the presence of R. necatrix in avocado soil and rhizosphere, minimizing its effect on the rest of the microbial communities. The bacterial treatment of formulated PcPCL1606 on avocado soils infested with R. necatrix resulted in biological control of the pathogen. This suppressiveness phenotype was analyzed, and PcPCL1606 has a key role in suppressiveness induction; in addition, this phenotype was strongly dependent on the production of HPR.
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Affiliation(s)
- Sandra Tienda
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Carmen Vida
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Ellen Lagendijk
- Koppert Biological Systems, Berkel en Rodenrijs, Netherlands
| | - Sandra de Weert
- Koppert Biological Systems, Berkel en Rodenrijs, Netherlands
| | - Irene Linares
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Jorge González-Fernández
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Estación Experimental “La Mayora”, Algarrobo, Spain
| | - Emilio Guirado
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Estación Experimental “La Mayora”, Algarrobo, Spain
| | - Antonio de Vicente
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
| | - Francisco M. Cazorla
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, IHSM-UMA-CSIC, Málaga, Spain
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19
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Comparative Analysis of the Core Proteomes among the Pseudomonas Major Evolutionary Groups Reveals Species-Specific Adaptations for Pseudomonas aeruginosa and Pseudomonas chlororaphis. DIVERSITY 2020. [DOI: 10.3390/d12080289] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The Pseudomonas genus includes many species living in diverse environments and hosts. It is important to understand which are the major evolutionary groups and what are the genomic/proteomic components they have in common or are unique. Towards this goal, we analyzed 494 complete Pseudomonas proteomes and identified 297 core-orthologues. The subsequent phylogenomic analysis revealed two well-defined species (Pseudomonas aeruginosa and Pseudomonas chlororaphis) and four wider phylogenetic groups (Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas syringae, Pseudomonas putida) with a sufficient number of proteomes. As expected, the genus-level core proteome was highly enriched for proteins involved in metabolism, translation, and transcription. In addition, between 39–70% of the core proteins in each group had a significant presence in each of all the other groups. Group-specific core proteins were also identified, with P. aeruginosa having the highest number of these and P. fluorescens having none. We identified several P. aeruginosa-specific core proteins (such as CntL, CntM, PlcB, Acp1, MucE, SrfA, Tse1, Tsi2, Tse3, and EsrC) that are known to play an important role in its pathogenicity. Finally, a holin family bacteriocin and a mitomycin-like biosynthetic protein were found to be core-specific for P. cholororaphis and we hypothesize that these proteins may confer a competitive advantage against other root-colonizers.
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20
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Abstract
Bacteria have evolved a wide range of mechanisms to harm and kill their competitors, including chemical, mechanical and biological weapons. Here we review the incredible diversity of bacterial weapon systems, which comprise antibiotics, toxic proteins, mechanical weapons that stab and pierce, viruses, and more. The evolution of bacterial weapons is shaped by many factors, including cell density and nutrient abundance, and how strains are arranged in space. Bacteria also employ a diverse range of combat behaviours, including pre-emptive attacks, suicidal attacks, and reciprocation (tit-for-tat). However, why bacteria carry so many weapons, and why they are so often used, remains poorly understood. By comparison with animals, we argue that the way that bacteria live - often in dense and genetically diverse communities - is likely to be key to their aggression as it encourages them to dig in and fight alongside their clonemates. The intensity of bacterial aggression is such that it can strongly affect communities, via complex coevolutionary and eco-evolutionary dynamics, which influence species over space and time. Bacterial warfare is a fascinating topic for ecology and evolution, as well as one of increasing relevance. Understanding how bacteria win wars is important for the goal of manipulating the human microbiome and other important microbial systems.
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21
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Kandel PP, Baltrus DA, Hockett KL. Pseudomonas Can Survive Tailocin Killing via Persistence-Like and Heterogenous Resistance Mechanisms. J Bacteriol 2020; 202:e00142-20. [PMID: 32312747 PMCID: PMC7283598 DOI: 10.1128/jb.00142-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 04/16/2020] [Indexed: 12/14/2022] Open
Abstract
Phage tail-like bacteriocins (tailocins) are bacterially produced protein toxins that mediate competitive interactions between cocolonizing bacteria. Both theoretical and experimental research has shown there are intransitive interactions between bacteriocin-producing, bacteriocin-sensitive, and bacteriocin-resistant populations, whereby producers outcompete sensitive cells, sensitive cells outcompete resistant cells, and resistant cells outcompete producers. These so-called rock-paper-scissors dynamics explain how all three populations occupy the same environment, without one driving the others extinct. Using Pseudomonas syringae as a model, we demonstrate that otherwise sensitive cells survive bacteriocin exposure through a physiological mechanism. This mechanism allows cells to survive bacteriocin killing without acquiring resistance. We show that a significant fraction of the target cells that survive a lethal dose of tailocin did not exhibit any detectable increase in survival during a subsequent exposure. Tailocin persister cells were more prevalent in stationary- rather than log-phase cultures. Of the fraction of cells that gained detectable resistance, there was a range from complete (insensitive) to incomplete (partially sensitive) resistance. By using genomic sequencing and genetic engineering, we showed that a mutation in a hypothetical gene containing 8 to 10 transmembrane domains causes tailocin high persistence and that genes of various glycosyltransferases cause incomplete and complete tailocin resistance. Importantly, of the several classes of mutations, only those causing complete tailocin resistance compromised host fitness. This result indicates that bacteria likely utilize persistence to survive bacteriocin-mediated killing without suffering the costs associated with resistance. This research provides important insight into how bacteria can escape the trap of fitness trade-offs associated with gaining de novo tailocin resistance.IMPORTANCE Bacteriocins are bacterially produced protein toxins that are proposed as antibiotic alternatives. However, a deeper understanding of the responses of target bacteria to bacteriocin exposure is lacking. Here, we show that target cells of Pseudomonas syringae survive lethal bacteriocin exposure through both physiological persistence and genetic resistance mechanisms. Cells that are not growing rapidly rely primarily on persistence, whereas those growing rapidly are more likely to survive via resistance. We identified various mutations in lipopolysaccharide biogenesis-related regions involved in tailocin persistence and resistance. By assessing host fitness of various classes of mutants, we showed that persistence and subtle resistance are mechanisms P. syringae uses to survive competition and preserve host fitness. These results have important implications for developing bacteriocins as alternative therapeutic agents.
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Affiliation(s)
- Prem P Kandel
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - David A Baltrus
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Kevin L Hockett
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, Pennsylvania, USA
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
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22
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Anderson AJ, Kim YC. Insights into plant-beneficial traits of probiotic Pseudomonas chlororaphis isolates. J Med Microbiol 2020; 69:361-371. [DOI: 10.1099/jmm.0.001157] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas chlororaphisisolates have been studied intensively for their beneficial traits.P. chlororaphisspecies function as probiotics in plants and fish, offering plants protection against microbes, nematodes and insects. In this review, we discuss the classification ofP. chlororaphisisolates within four subspecies; the shared traits include the production of coloured antimicrobial phenazines, high sequence identity between housekeeping genes and similar cellular fatty acid composition. The direct antimicrobial, insecticidal and nematocidal effects ofP. chlororaphisisolates are correlated with known metabolites. Other metabolites prime the plants for stress tolerance and participate in microbial cell signalling events and biofilm formation among other things. Formulations ofP. chlororaphisisolates and their metabolites are currently being commercialized for agricultural use.
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Affiliation(s)
- Anne J. Anderson
- Department of Biological Engineering, Utah State University, Logan UT84322, USA
| | - Young Cheol Kim
- Department of Applied Biology, Chonnam National University, Gwangju 61186, Republic of Korea
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23
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Characterization of the bacteriocins and the PrtR regulator in a plant-associated Pseudomonas strain. J Biotechnol 2020; 307:182-192. [DOI: 10.1016/j.jbiotec.2019.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 09/16/2019] [Accepted: 11/03/2019] [Indexed: 11/20/2022]
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24
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Beaton A, Lood C, Cunningham-Oakes E, MacFadyen A, Mullins AJ, Bestawy WE, Botelho J, Chevalier S, Coleman S, Dalzell C, Dolan SK, Faccenda A, Ghequire MGK, Higgins S, Kutschera A, Murray J, Redway M, Salih T, da Silva AC, Smith BA, Smits N, Thomson R, Woodcock S, Welch M, Cornelis P, Lavigne R, van Noort V, Tucker NP. Community-led comparative genomic and phenotypic analysis of the aquaculture pathogen Pseudomonas baetica a390T sequenced by Ion semiconductor and Nanopore technologies. FEMS Microbiol Lett 2019; 365:4951603. [PMID: 29579234 PMCID: PMC5909648 DOI: 10.1093/femsle/fny069] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 03/21/2018] [Indexed: 12/29/2022] Open
Abstract
Pseudomonas baetica strain a390T is the type strain of this recently described species and here we present its high-contiguity draft genome. To celebrate the 16th International Conference on Pseudomonas, the genome of P. baetica strain a390T was sequenced using a unique combination of Ion Torrent semiconductor and Oxford Nanopore methods as part of a collaborative community-led project. The use of high-quality Ion Torrent sequences with long Nanopore reads gave rapid, high-contiguity and -quality, 16-contig genome sequence. Whole genome phylogenetic analysis places P. baetica within the P. koreensis clade of the P. fluorescens group. Comparison of the main genomic features of P. baetica with a variety of other Pseudomonas spp. suggests that it is a highly adaptable organism, typical of the genus. This strain was originally isolated from the liver of a diseased wedge sole fish, and genotypic and phenotypic analyses show that it is tolerant to osmotic stress and to oxytetracycline.
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Affiliation(s)
- Ainsley Beaton
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Cédric Lood
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium.,Laboratory of Gene Technology, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium
| | - Edward Cunningham-Oakes
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Park Place, Cardiff CF10 3AX, UK
| | - Alison MacFadyen
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Midlothian EH25 9RG, Scotland, UK
| | - Alex J Mullins
- Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Park Place, Cardiff CF10 3AX, UK
| | - Walid El Bestawy
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - João Botelho
- UCIBIO/REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira no. 228 Porto 4050-313, Portugal
| | - Sylvie Chevalier
- Laboratoire Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen, 55, rue St Germain, Evreux 27000, France
| | - Shannon Coleman
- Lower Mall Research Station, University of British Columbia, 2259 Lower Mall, Vancouver, BC V6T 1Z4, Canada
| | - Chloe Dalzell
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Stephen K Dolan
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Alberto Faccenda
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Maarten G K Ghequire
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium
| | - Steven Higgins
- Department of Plant and Microbial Biology, University of Zürich, Zürich 8008, Switzerland
| | - Alexander Kutschera
- Department of Phytopathology, Center of Life and Food Sciences, Technical University of Munich, Weihenstephan D-85354, Germany
| | - Jordan Murray
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Martha Redway
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Talal Salih
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Ana C da Silva
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Brian A Smith
- School of Plant Sciences, The University of Arizona, P.O. Box 210036, Forbes Building, 303 Tucson, Arizona 85721-0036, USA
| | - Nathan Smits
- Laboratory of Gene Technology, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium
| | - Ryan Thomson
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Stuart Woodcock
- Department of Biological Chemistry, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Hopkins Building, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Pierre Cornelis
- Laboratoire Microbiologie Signaux et Microenvironnement (LMSM), Université de Rouen, 55, rue St Germain, Evreux 27000, France
| | - Rob Lavigne
- Laboratory of Gene Technology, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium
| | - Vera van Noort
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, bus 2460, Leuven B-3001, Belgium
| | - Nicholas P Tucker
- Strathclyde Institute of Pharmacy and Biomedical Science, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
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25
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Zhou Y, Gao X. Characterization of Biofilm Formed by Phenanthrene-Degrading Bacteria on Rice Root Surfaces for Reduction of PAH Contamination in Rice. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E2002. [PMID: 31195653 PMCID: PMC6603869 DOI: 10.3390/ijerph16112002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/28/2019] [Accepted: 05/31/2019] [Indexed: 01/13/2023]
Abstract
One effective method in to reduce the uptake of organic contaminants by plants is the development of a root barrier. In this study, the characterization of biofilm structure and function by phenanthrene-degrading Pseudomonas sp. JM2-gfp on rice root surfaces were carried out. Our results showed that root surfaces from three rice species, namely Liaojing401, Koshihikari, and Zhenzhuhong all present hydrophobicity and a high initial adhesion of strain JM2-gfp. Matured robust biofilm formation occurred at 48 h on the root surfaces. The biofilm exhibited cell dense aggregates and biomass embedded in the extracellular polymeric substance (EPS) matrix. EPS composition results showed that the proteins, carbohydrates, lipids and nucleic acids are produced in the biofilm, while the content varied with rice species. Under the initial concentration of phenanthrene 50 mg·L-1, the residual phenanthrene in plant roots from 'Zhengzhuhong', 'Koshihikari' and 'Liaojing401' with biofilm mediated were significantly decreased by 71.9%, 69.3% and 58.7%, respectively, compared to those without biofilm groups after 10 days of exposure. Thus, the biofilm colonized on roots plays an important role of degradation in order to reduce the level of phenanthrene uptake of plants. Thereby, the present work provides significant new insights into lowering the environmental risks of polycyclic aromatic hydrocarbons (PAHs) in crop products from contaminated agriculture soils.
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Affiliation(s)
- Yuman Zhou
- Liaoning Key Laboratory of Molecular Recognition and Imaging, School of Bioengineering, Dalian University of Technology, Dalian 116023, China.
| | - Xiaorong Gao
- Liaoning Key Laboratory of Molecular Recognition and Imaging, School of Bioengineering, Dalian University of Technology, Dalian 116023, China.
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26
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Patz S, Becker Y, Richert-Pöggeler KR, Berger B, Ruppel S, Huson DH, Becker M. Phage tail-like particles are versatile bacterial nanomachines - A mini-review. J Adv Res 2019; 19:75-84. [PMID: 31341672 PMCID: PMC6629978 DOI: 10.1016/j.jare.2019.04.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 04/06/2019] [Accepted: 04/14/2019] [Indexed: 11/27/2022] Open
Abstract
Suggestion to simplify and unify the nomenclature of phage tail-like particles. Discovery of kosakonicin, a new bacteriocin and tailocin. Microscopy of kosakonicin from Kosakonia radicincitans DSM 16656. Discovery of multiple tail fiber genes in the kosakonicin gene cluster. Discovery of large genetic diversity in the kosakonicin tail fiber locus among ten Kosakonia strains.
Type VI secretion systems and tailocins, two bacterial phage tail-like particles, have been reported to foster interbacterial competition. Both nanostructures enable their producer to kill other bacteria competing for the same ecological niche. Previously, type VI secretion systems and particularly R-type tailocins were considered highly specific, attacking a rather small range of competitors. Their specificity is conferred by cell surface receptors of the target bacterium and receptor-binding proteins on tailocin tail fibers and tail fiber-like appendages of T6SS. Since many R-type tailocin gene clusters contain only one tail fiber gene it was appropriate to expect small R-type tailocin target ranges. However, recently up to three tail fiber genes and broader target ranges have been reported for one plant-associated Pseudomonas strain. Here, we show that having three tail fiber genes per R-type tailocin gene cluster is a common feature of several strains of Gram-negative (often plant-associated) bacteria of the genus Kosakonia. Knowledge about the specificity of type VI secretion systems binding to target bacteria is even lower than in R-type tailocins. Although the mode of operation implicated specific binding, it was only published recently that type VI secretion systems develop tail fiber-like appendages. Here again Kosakonia, exhibiting up to three different type VI secretion systems, may provide valuable insights into the antagonistic potential of plant-associated bacteria. Current understanding of the diversity and potential of phage tail-like particles is fragmentary due to various synonyms and misleading terminology. Consistency in technical terms is a precondition for concerted and purposeful research, which precedes a comprehensive understanding of the specific interaction between bacteria producing phage tail-like particles and their targets. This knowledge is fundamental for selecting and applying tailored, and possibly engineered, producer bacteria for antagonizing plant pathogenic microorganisms.
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Affiliation(s)
- Sascha Patz
- Algorithms in Bioinformatics, Center for Bioinformatics, University of Tübingen, 72074 Tübingen, Germany
| | - Yvonne Becker
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute - Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany
| | - Katja R Richert-Pöggeler
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institute - Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany
| | - Beatrice Berger
- Institute for National and International Plant Health, Julius Kühn-Institute - Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany
| | - Silke Ruppel
- Leibniz Institute of Vegetable and Ornamental Crops, 14979 Grossbeeren, Germany
| | - Daniel H Huson
- Algorithms in Bioinformatics, Center for Bioinformatics, University of Tübingen, 72074 Tübingen, Germany
| | - Matthias Becker
- Institute for National and International Plant Health, Julius Kühn-Institute - Federal Research Centre for Cultivated Plants, 38104 Braunschweig, Germany.,Leibniz Institute of Vegetable and Ornamental Crops, 14979 Grossbeeren, Germany
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27
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Arrebola E, Tienda S, Vida C, de Vicente A, Cazorla FM. Fitness Features Involved in the Biocontrol Interaction of Pseudomonas chlororaphis With Host Plants: The Case Study of PcPCL1606. Front Microbiol 2019; 10:719. [PMID: 31024497 PMCID: PMC6469467 DOI: 10.3389/fmicb.2019.00719] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/21/2019] [Indexed: 12/31/2022] Open
Abstract
The goal of this mini review is to summarize the relevant contribution of some beneficial traits to the behavior of the species Pseudomonas chlororaphis, and using that information, to give a practical point of view using the model biocontrol strain P. chlororaphis PCL1606 (PcPCL1606). Among the group of plant-beneficial rhizobacteria, P. chlororaphis has emerged as a plant- and soil-related bacterium that is mainly known because of its biological control of phytopathogenic fungi. Many traits have been reported to be crucial during the multitrophic interaction involving the plant, the fungal pathogen and the soil environment. To explore the different biocontrol-related traits, the biocontrol rhizobacterium PcPCL1606 has been used as a model in recent studies. This bacterium is antagonistic to many phytopathogenic fungi and displays effective biocontrol against fungal phytopathogens. Antagonistic and biocontrol activities are directly related to the production of the compound 2-hexyl, 5-propyl resorcinol (HPR), despite the production of other antifungal compounds. Furthermore, PcPCL1606 has displayed additional traits regarding its fitness in soil and plant root environments such as soil survival, efficient plant root colonization, cell-to-cell interaction or promotion of plant growth.
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Affiliation(s)
- Eva Arrebola
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" IHSM, UMA-CSIC, Málaga, Spain
| | - Sandra Tienda
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" IHSM, UMA-CSIC, Málaga, Spain
| | - Carmen Vida
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" IHSM, UMA-CSIC, Málaga, Spain
| | - Antonio de Vicente
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" IHSM, UMA-CSIC, Málaga, Spain
| | - Francisco M Cazorla
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" IHSM, UMA-CSIC, Málaga, Spain
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28
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Ghequire MGK, Öztürk B, De Mot R. Lectin-Like Bacteriocins. Front Microbiol 2018; 9:2706. [PMID: 30483232 PMCID: PMC6240691 DOI: 10.3389/fmicb.2018.02706] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/23/2018] [Indexed: 12/22/2022] Open
Abstract
Bacteria produce a diverse array of antagonistic compounds to restrict growth of microbial rivals. Contributing to this warfare are bacteriocins: secreted antibacterial peptides, proteins and multi-protein complexes. These compounds typically eliminate competitors closely related to the producer. Lectin-like bacteriocins (LlpAs) constitute a distinct class of such proteins, produced by Pseudomonas as well as some other proteobacterial genera. LlpAs share a common architecture consisting of two B-lectin domains, followed by a short carboxy-terminal extension. Two surface-exposed moieties on susceptible Pseudomonas cells are targeted by the respective lectin modules. The carboxy-terminal domain binds D-rhamnose residues present in the lipopolysaccharide layer, whereas the amino-terminal domain interacts with a polymorphic external loop of the outer-membrane protein insertase BamA, hence determining selectivity. The absence of a toxin-immunity module as found in modular bacteriocins and other polymorphic toxin systems, hints toward a novel mode of killing initiated at the cellular surface, not requiring bacteriocin import. Despite significant progress in understanding the function of LlpAs, outstanding questions include the secretion machinery recruited by lectin-like bacteriocins for their release, as well as a better understanding of the environmental signals initiating their expression.
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Affiliation(s)
| | - Başak Öztürk
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen, Braunschweig, Germany
| | - René De Mot
- Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
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29
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Pseudomonas chlororaphis Produces Multiple R-Tailocin Particles That Broaden the Killing Spectrum and Contribute to Persistence in Rhizosphere Communities. Appl Environ Microbiol 2018; 84:AEM.01230-18. [PMID: 30030224 DOI: 10.1128/aem.01230-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/10/2018] [Indexed: 12/18/2022] Open
Abstract
R-tailocins are high-molecular-weight bacteriocins resembling bacteriophage tails. Pseudomonas chlororaphis 30-84 is a plant growth-promoting rhizobacterial (PGPR) strain that produces two distinct R-tailocin particles with different killing spectra. The two R-tailocins have different evolutionary histories but are released by the same lysis cassette. A previous study showed that both tailocins are important for pairwise competition with susceptible rhizosphere-colonizing strains; however, the broader role of tailocins in competition with the native rhizosphere microbiome was not tested. Genomic analysis of the P. chlororaphis 30-84 R-tailocin gene cluster uncovered the presence of three tail fiber genes in the tailocin 2 genetic module that could potentially result in tailocin 2 particles having different tail fibers and thus a wider killing spectrum. In this study, the tail fibers were found to incorporate onto different tailocin 2 particles, each with a distinct killing spectrum. A loss of production of one or both tailocins resulted in decreased P. chlororaphis 30-84 persistence within the wheat rhizosphere when in competition with the native microflora but not bulk soil. The capacity to produce three different versions of a single tailocin, each having one of three different types of tail fibers, is a previously unreported mechanism that leads to a broader R-tailocin killing spectrum. This study also provides evidence for the function of R-tailocins in competition with rhizosphere microbiome communities but not in bulk soil.IMPORTANCE Although R-tailocin gene clusters typically encode one tail fiber protein, three tail fiber-resembling genes were identified in association with one of the two sets of R-tailocin genes within the tailocin cluster of P. chlororaphis 30-84 and other sequenced P. chlororaphis strain genomes. This study confirmed that P. chlororaphis 30-84 not only produces two distinct tailocins, but that one of them is produced with three different types of tail fibers. This is a previously unreported strategy to increase the breadth of strains targeted by an R-tailocin. Our finding that R-tailocins produced by a PGPR Pseudomonas strain enhanced its persistence within the wheat rhizosphere microbiome confirms that R-tailocin production contributes to the population dynamics of rhizobacterial communities.
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30
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Príncipe A, Fernandez M, Torasso M, Godino A, Fischer S. Effectiveness of tailocins produced by Pseudomonas fluorescens SF4c in controlling the bacterial-spot disease in tomatoes caused by Xanthomonas vesicatoria. Microbiol Res 2018; 212-213:94-102. [DOI: 10.1016/j.micres.2018.05.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/13/2018] [Accepted: 05/12/2018] [Indexed: 01/24/2023]
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31
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Abstract
Lectin-like bacteriocins (LlpAs) are secreted by proteobacteria and selectively kill strains of their own or related species, and they are composed of two B-lectin domains with divergent sequences. In Pseudomonas spp., initial binding of these antibacterial proteins to cells is mediated by the carboxy-terminal domain through d-rhamnose residues present in the common polysaccharide antigen of their lipopolysaccharide, whereas the amino-terminal domain accounts for strain selectivity of killing. Here, we show that spontaneous LlpA-resistant mutants carry mutations in one of three surface-exposed moieties of the essential β-barrel outer membrane protein insertase BamA, the core component of the BAM complex. Polymorphism of this loop in different Pseudomonas groups is linked to LlpA susceptibility, and targeted cells all share the same signature motif in this loop. Since heterologous expression of such a bamA gene confers LlpA susceptibility upon a resistant strain, BamA represents the primary bacteriocin selectivity determinant in pseudomonads. Contrary to modular bacteriocins that require uptake via the Tol or Ton system, parasitism of BamA as an LlpA receptor advocates a novel bacteriocin killing mechanism initiated by impairment of the BAM machinery. Bacteria secrete a variety of molecules to eliminate microbial rivals. Bacteriocins are a pivotal group of peptides and proteins that assist in this fight, specifically killing related bacteria. In Gram-negative bacteria, these antibacterial proteins often comprise distinct domains for initial binding to a target cell’s surface and subsequent killing via enzymatic or pore-forming activity. Here, we show that lectin-like bacteriocins, a family of bacteriocins that lack the prototypical modular toxin architecture, also stand out by parasitizing BamA, the core component of the outer membrane protein assembly machinery. A particular surface-exposed loop of BamA, critical for its function, serves as a key discriminant for cellular recognition, and polymorphisms in this loop determine whether a strain is susceptible or immune to a particular bacteriocin. These findings suggest a novel mechanism of contact-dependent killing that does not require cellular uptake. The evolutionary advantage of piracy of an essential cellular compound is highlighted by the observation that contact-dependent growth inhibition, a distinct antagonistic system, can equally take advantage of this receptor.
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