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Brandl MT, Ivanek R, Zekaj N, Belias A, Wiedmann M, Suslow TV, Allende A, Munther DS. Weather stressors correlate with Escherichia coli and Salmonella enterica persister formation rates in the phyllosphere: a mathematical modeling study. ISME COMMUNICATIONS 2022; 2:91. [PMID: 37938340 PMCID: PMC9723732 DOI: 10.1038/s43705-022-00170-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 10/10/2023]
Abstract
Enteric pathogens can enter a persister state in which they survive exposure to antibiotics and physicochemical stresses. Subpopulations of such phenotypic dormant variants have been detected in vivo and in planta in the laboratory, but their formation in the natural environment remains largely unexplored. We applied a mathematical model predicting the switch rate to persister cell in the phyllosphere to identify weather-related stressors associated with E. coli and S. enterica persister formation on plants based on their population dynamics in published field studies from the USA and Spain. Model outputs accurately depicted the bi-phasic decay of bacterial population sizes measured in the lettuce and spinach phyllosphere in these studies. Predicted E. coli persister switch rate on leaves was positively and negatively correlated with solar radiation intensity and wind velocity, respectively. Likewise, predicted S. enterica persister switch rate correlated positively with solar radiation intensity; however, a negative correlation was observed with air temperature, relative humidity, and dew point, factors involved in water deposition onto the phylloplane. These findings suggest that specific environmental factors may enrich for dormant bacterial cells on plants. Our model quantifiably links persister cell subpopulations in the plant habitat with broader physical conditions, spanning processes at different granular scales.
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Affiliation(s)
- Maria T Brandl
- Produce Safety and Microbiology Research Unit, US Department of Agriculture, Agricultural Research Service, Albany, CA, 94710, USA.
| | - Renata Ivanek
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Nerion Zekaj
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, OH, 44115, USA
| | - Alexandra Belias
- Department of Food Science, Cornell University, Ithaca, NY, 14853, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, 14853, USA
| | - Trevor V Suslow
- Department of Plant Sciences, University of California, Davis, CA, 95616, USA
| | - Ana Allende
- Research Group of Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIS, Campus Universitario de Espinardo, Murcia, E-30100, Spain
| | - Daniel S Munther
- Department of Mathematics and Statistics, Cleveland State University, Cleveland, OH, 44115, USA.
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Slack SM, Walters KJ, Outwater CA, Sundin GW. Effect of Kasugamycin, Oxytetracycline, and Streptomycin on In-orchard Population Dynamics of Erwinia amylovora on Apple Flower Stigmas. PLANT DISEASE 2021; 105:1843-1850. [PMID: 33044145 DOI: 10.1094/pdis-07-20-1469-re] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We assessed the effect of three antibiotics (streptomycin, oxytetracycline, and kasugamycin) on populations of the fire blight pathogen Erwinia amylovora on apple flower stigmas during three field seasons. Application timing relative to E. amylovora presence on flower stigmas had little impact on population dynamics and subsequent disease incidence. Although E. amylovora populations on water-treated flowers increased to 106-7 cfu flower-1 after 4 to 5 days during each experiment, the antibiotics streptomycin and kasugamycin caused statistically significant reductions in stigma populations by as many as 4 to 5 logs over a 4- to 5-day period during two of the three experiments. In contrast, the effect of oxytetracycline on E. amylovora populations on stigmas was more variable, with reductions in E. amylovora populations only observed during one of the three experiments. In agreement with the population data, the disease incidence was significantly higher for oxytetracycline-treated flowers compared with the other antibiotic treatments during 2 of 3 years. Statistical analyses of the effects of weather parameters on antibiotic activity revealed that solar radiation and temperature negatively impacted the activity of both kasugamycin and oxytetracycline. We further assessed the potential for photodegradation of formulated kasugamycin (Kasumin 2L) and found that Kasumin 2L was susceptible to degradation in vitro after exposure to a 16-h photoperiod of daily light integrals (DLIs) varying from 6 to 35 mol⋅m-2⋅d-1. We further determined that exposure to three consecutive 16-h photoperiods of DLIs of 23 or 35 mol⋅m-2⋅d-1 reduced the available concentration of Kasumin 2L (assessed using a bioassay) from 100 μg⋅ml-1 to 10 to 20 μg⋅ml-1. Our results correlate the superior blossom blight control efficacy of kasugamycin and streptomycin with significant population reductions in E. amylovora on apple flower stigmas but indicate that, similar to oxytetracycline, kasugamycin is vulnerable to photodegradation, which would suggest that further considerations are necessary when applying this antibiotic.
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Affiliation(s)
- Suzanne M Slack
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Kellie J Walters
- Department of Horticulture, Michigan State University, East Lansing, MI 48824
| | - Cory A Outwater
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
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Vanhaelewyn L, Van Der Straeten D, De Coninck B, Vandenbussche F. Ultraviolet Radiation From a Plant Perspective: The Plant-Microorganism Context. FRONTIERS IN PLANT SCIENCE 2020; 11:597642. [PMID: 33384704 PMCID: PMC7769811 DOI: 10.3389/fpls.2020.597642] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/19/2020] [Indexed: 05/20/2023]
Abstract
Ultraviolet (UV) radiation directly affects plants and microorganisms, but also alters the species-specific interactions between them. The distinct bands of UV radiation, UV-A, UV-B, and UV-C have different effects on plants and their associated microorganisms. While UV-A and UV-B mainly affect morphogenesis and phototropism, UV-B and UV-C strongly trigger secondary metabolite production. Short wave (<350 nm) UV radiation negatively affects plant pathogens in direct and indirect ways. Direct effects can be ascribed to DNA damage, protein polymerization, enzyme inactivation and increased cell membrane permeability. UV-C is the most energetic radiation and is thus more effective at lower doses to kill microorganisms, but by consequence also often causes plant damage. Indirect effects can be ascribed to UV-B specific pathways such as the UVR8-dependent upregulated defense responses in plants, UV-B and UV-C upregulated ROS accumulation, and secondary metabolite production such as phenolic compounds. In this review, we summarize the physiological and molecular effects of UV radiation on plants, microorganisms and their interactions. Considerations for the use of UV radiation to control microorganisms, pathogenic as well as non-pathogenic, are listed. Effects can be indirect by increasing specialized metabolites with plant pre-treatment, or by directly affecting microorganisms.
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Affiliation(s)
- Lucas Vanhaelewyn
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
| | | | - Barbara De Coninck
- Plant Health and Protection Laboratory, Division of Crop Biotechnics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Filip Vandenbussche
- Laboratory of Functional Plant Biology, Department of Biology, Ghent University, Ghent, Belgium
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Wang B, Liang X, Gleason ML, Zhang R, Sun G. Genome sequence of the ectophytic fungus Ramichloridium luteum reveals unique evolutionary adaptations to plant surface niche. BMC Genomics 2017; 18:729. [PMID: 28915794 PMCID: PMC5602860 DOI: 10.1186/s12864-017-4118-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/05/2017] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Ectophytic fungi occupy the waxy plant surface, an extreme environment characterized by prolonged desiccation, nutrient limitation, and exposure to solar radiation. The nature of mechanisms that facilitate adaptation to this environment remains unclear. In this study, we sequenced the complete genome of an ectophytic fungus, Ramichloridium luteum, which colonizes the surface of apple fruit, and carried out comparative genomic and transcriptome analysis. RESULTS The R. luteum genome was 28.18 Mb and encoded 9466 genes containing 1.85% repetitive elements. Compared with cell-penetrating pathogens, genes encoding plant cell wall degrading enzymes (PCWDEs), PTH11-like G protein-coupled receptors (GPCRs) and effectors were drastically reduced. In contrast, genes encoding cutinases and secretory lipases were strikingly expanded, and four of nine secretory lipases were probably acquired by horizontal gene transfer from Basidiomycota. Transcriptomic analysis revealed elevated expression of genes involved in cuticle degradation (cutinase, secretory lipase) and stress responses (melanin biosynthesis, aquaporins, lysozymes and HOG pathway). CONCLUSIONS Taken together, our results highlight genomic features associated with evolution of surface niche adaptation by the ectophytic fungus R. luteum, namely the contraction of PCWDEs, PTH11-like GPCRs and effectors, and the expansion of cuticle degradation and stress tolerance.
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Affiliation(s)
- Bo Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province 712100 China
| | - Xiaofei Liang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province 712100 China
| | - Mark L. Gleason
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011 USA
| | - Rong Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province 712100 China
| | - Guangyu Sun
- State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi Province 712100 China
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Shidore T, Triplett LR. Toxin-Antitoxin Systems: Implications for Plant Disease. ANNUAL REVIEW OF PHYTOPATHOLOGY 2017; 55:161-179. [PMID: 28525308 DOI: 10.1146/annurev-phyto-080516-035559] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Toxin-antitoxin (TA) systems are gene modules that are ubiquitous in free-living prokaryotes. Diverse in structure, cellular function, and fitness roles, TA systems are defined by the presence of a toxin gene that suppresses bacterial growth and a toxin-neutralizing antitoxin gene, usually encoded in a single operon. Originally viewed as DNA maintenance modules, TA systems are now thought to function in many roles, including bacterial stress tolerance, virulence, phage defense, and biofilm formation. However, very few studies have investigated the significance of TA systems in the context of plant-microbe interactions. This review discusses the potential impact and application of TA systems in plant-associated bacteria, guided by insights gained from animal-pathogenic model systems.
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Affiliation(s)
- T Shidore
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511:
| | - L R Triplett
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, New Haven, Connecticut 06511:
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Baltrus DA, McCann HC, Guttman DS. Evolution, genomics and epidemiology of Pseudomonas syringae: Challenges in Bacterial Molecular Plant Pathology. MOLECULAR PLANT PATHOLOGY 2017; 18:152-168. [PMID: 27798954 PMCID: PMC6638251 DOI: 10.1111/mpp.12506] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 05/12/2023]
Abstract
A remarkable shift in our understanding of plant-pathogenic bacteria is underway. Until recently, nearly all research on phytopathogenic bacteria was focused on a small number of model strains, which provided a deep, but narrow, perspective on plant-microbe interactions. Advances in genome sequencing technologies have changed this by enabling the incorporation of much greater diversity into comparative and functional research. We are now moving beyond a typological understanding of a select collection of strains to a more generalized appreciation of the breadth and scope of plant-microbe interactions. The study of natural populations and evolution has particularly benefited from the expansion of genomic data. We are beginning to have a much deeper understanding of the natural genetic diversity, niche breadth, ecological constraints and defining characteristics of phytopathogenic species. Given this expanding genomic and ecological knowledge, we believe the time is ripe to evaluate what we know about the evolutionary dynamics of plant pathogens.
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Affiliation(s)
| | - Honour C. McCann
- New Zealand Institute for Advanced StudyMassey UniversityAuckland 0632New Zealand
| | - David S. Guttman
- Department of Cell and Systems BiologyUniversity of TorontoTorontoON M5S 3B2Canada
- Centre for the Analysis of Genome Evolution and FunctionUniversity of TorontoTorontoON M5S 3B2Canada
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Bonomi HR, Toum L, Sycz G, Sieira R, Toscani AM, Gudesblat GE, Leskow FC, Goldbaum FA, Vojnov AA, Malamud F. Xanthomonas campestris attenuates virulence by sensing light through a bacteriophytochrome photoreceptor. EMBO Rep 2016; 17:1565-1577. [PMID: 27621284 DOI: 10.15252/embr.201541691] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 08/02/2016] [Indexed: 11/09/2022] Open
Abstract
Phytochromes constitute a major photoreceptor family found in plants, algae, fungi, and prokaryotes, including pathogens. Here, we report that Xanthomonas campestris pv. campestris (Xcc), the causal agent of black rot disease which affects cruciferous crops worldwide, codes for a functional bacteriophytochrome (XccBphP). XccBphP possesses an N-terminal PAS2-GAF-PHY photosensory domain triad and a C-terminal PAS9 domain as its output module. Our results show that illumination of Xcc, prior to plant infection, attenuates its virulence in an XccBphP-dependent manner. Moreover, in response to light, XccBphP downregulates xanthan exopolysaccharide production and biofilm formation, two known Xcc virulence factors. Furthermore, the XccbphP null mutant shows enhanced virulence, similar to that of dark-adapted Xcc cultures. Stomatal aperture regulation and callose deposition, both well-established plant defense mechanisms against bacterial pathogens, are overridden by the XccbphP strain. Additionally, an RNA-Seq analysis reveals that far-red light or XccBphP overexpression produces genomewide transcriptional changes, including the inhibition of several Xcc virulence systems. Our findings indicate that Xcc senses light through XccBphP, eliciting bacterial virulence attenuation via downregulation of bacterial virulence factors. The capacity of XccBphP to respond to light both in vitro and in vivo was abolished by a mutation on the conserved Cys13 residue. These results provide evidence for a novel bacteriophytochrome function affecting an infectious process.
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Affiliation(s)
- Hernán R Bonomi
- Fundación Instituto Leloir - IIBBA CONICET, Buenos Aires, Argentina
| | - Laila Toum
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Buenos Aires, Argentina
| | - Gabriela Sycz
- Fundación Instituto Leloir - IIBBA CONICET, Buenos Aires, Argentina
| | - Rodrigo Sieira
- Fundación Instituto Leloir - IIBBA CONICET, Buenos Aires, Argentina
| | - Andrés M Toscani
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo E Gudesblat
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Buenos Aires, Argentina
| | - Federico C Leskow
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Adrián A Vojnov
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Buenos Aires, Argentina
| | - Florencia Malamud
- Instituto de Ciencia y Tecnología Dr. Cesar Milstein, Fundación Pablo Cassará, CONICET, Buenos Aires, Argentina .,UNSAM Campus Miguelete IIB - Instituto de Investigaciones Biotecnológicas, Buenos Aires, Argentina
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8
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Sunlight and Soil–Litter Mixing: Drivers of Litter Decomposition in Drylands. PROGRESS IN BOTANY 2015. [DOI: 10.1007/978-3-319-08807-5_11] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Karentz D. Beyond xeroderma pigmentosum: DNA damage and repair in an ecological context. A tribute to James E. Cleaver. Photochem Photobiol 2014; 91:460-74. [PMID: 25395165 DOI: 10.1111/php.12388] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 10/29/2014] [Indexed: 12/12/2022]
Abstract
The ability to repair DNA is a ubiquitous characteristic of life on Earth and all organisms possess similar mechanisms for dealing with DNA damage, an indication of a very early evolutionary origin for repair processes. James E. Cleaver's career (initiated in the early 1960s) has been devoted to the study of mammalian ultraviolet radiation (UVR) photobiology, specifically the molecular genetics of xeroderma pigmentosum and other human diseases caused by defects in DNA damage recognition and repair. This work by Jim and others has influenced the study of DNA damage and repair in a variety of taxa. Today, the field of DNA repair is enhancing our understanding of not only how to treat and prevent human disease, but is providing insights on the evolutionary history of life on Earth and how natural populations are coping with UVR-induced DNA damage from anthropogenic changes in the environment such as ozone depletion.
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Affiliation(s)
- Deneb Karentz
- Department of Biology, University of San Francisco, San Francisco, CA
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Stockwell VO, Davis EW, Carey A, Shaffer BT, Mavrodi DV, Hassan KA, Hockett K, Thomashow LS, Paulsen IT, Loper JE. pA506, a conjugative plasmid of the plant epiphyte Pseudomonas fluorescens A506. Appl Environ Microbiol 2013; 79:5272-82. [PMID: 23811504 PMCID: PMC3753976 DOI: 10.1128/aem.01354-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/21/2013] [Indexed: 11/20/2022] Open
Abstract
Conjugative plasmids are known to facilitate the acquisition and dispersal of genes contributing to the fitness of Pseudomonas spp. Here, we report the characterization of pA506, the 57-kb conjugative plasmid of Pseudomonas fluorescens A506, a plant epiphyte used in the United States for the biological control of fire blight disease of pear and apple. Twenty-nine of the 67 open reading frames (ORFs) of pA506 have putative functions in conjugation, including a type IV secretion system related to that of MOBP6 family plasmids and a gene cluster for type IV pili. We demonstrate that pA506 is self-transmissible via conjugation between A506 and strains of Pseudomonas spp. or the Enterobacteriaceae. The origin of vegetative replication (oriV) of pA506 is typical of those in pPT23A family plasmids, which are present in many pathovars of Pseudomonas syringae, but pA506 lacks repA, a defining locus for pPT23A plasmids, and has a novel partitioning region. We selected a plasmid-cured derivative of A506 and compared it to the wild type to identify plasmid-encoded phenotypes. pA506 conferred UV resistance, presumably due to the plasmid-borne rulAB genes, but did not influence epiphytic fitness of A506 on pear or apple blossoms in the field. pA506 does not appear to confer resistance to antibiotics or other toxic elements. Based on the conjugative nature of pA506 and the large number of its genes that are shared with plasmids from diverse groups of environmental bacteria, the plasmid is likely to serve as a vehicle for genetic exchange between A506 and its coinhabitants on plant surfaces.
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Affiliation(s)
- Virginia O. Stockwell
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
| | - Edward W. Davis
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
- Agricultural Research Service, U.S. Department of Agriculture, Corvallis, Oregon, USA
| | - Alyssa Carey
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
- Agricultural Research Service, U.S. Department of Agriculture, Corvallis, Oregon, USA
| | - Brenda T. Shaffer
- Agricultural Research Service, U.S. Department of Agriculture, Corvallis, Oregon, USA
| | - Dmitri V. Mavrodi
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA
| | - Karl A. Hassan
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, Australia
| | - Kevin Hockett
- Agricultural Research Service, U.S. Department of Agriculture, Corvallis, Oregon, USA
| | - Linda S. Thomashow
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA
- Agricultural Research Service, U.S. Department of Agriculture, Pullman, Washington, USA
| | - Ian T. Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, Australia
| | - Joyce E. Loper
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
- Agricultural Research Service, U.S. Department of Agriculture, Corvallis, Oregon, USA
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Abstract
Our knowledge of the microbiology of the phyllosphere, or the aerial parts of plants, has historically lagged behind our knowledge of the microbiology of the rhizosphere, or the below-ground habitat of plants, particularly with respect to fundamental questions such as which microorganisms are present and what they do there. In recent years, however, this has begun to change. Cultivation-independent studies have revealed that a few bacterial phyla predominate in the phyllosphere of different plants and that plant factors are involved in shaping these phyllosphere communities, which feature specific adaptations and exhibit multipartite relationships both with host plants and among community members. Insights into the underlying structural principles of indigenous microbial phyllosphere populations will help us to develop a deeper understanding of the phyllosphere microbiota and will have applications in the promotion of plant growth and plant protection.
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Affiliation(s)
- Julia A Vorholt
- Institute of Microbiology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Wolfgang-Pauli-Strasse 10, HCI F429, 8093 Zurich, Switzerland.
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12
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Induction of Weigle reactivation of cyanophage PP in Plectonema boryanum. ANN MICROBIOL 2012. [DOI: 10.1007/s13213-011-0305-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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13
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Remus-Emsermann MNP, Leveau JHJ. Linking environmental heterogeneity and reproductive success at single-cell resolution. ISME JOURNAL 2009; 4:215-22. [DOI: 10.1038/ismej.2009.110] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Cazorla FM, Codina JC, Abad C, Arrebola E, Torés JA, Murillo J, Pérez-García A, de Vicente A. 62-kb plasmids harboring rulAB homologues confer UV-tolerance and epiphytic fitness to Pseudomonas syringae pv. syringae mango isolates. MICROBIAL ECOLOGY 2008; 56:283-291. [PMID: 18058161 DOI: 10.1007/s00248-007-9346-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 10/30/2007] [Accepted: 11/08/2007] [Indexed: 05/25/2023]
Abstract
The presence of genetic determinants homologous to rulAB genes for ultraviolet (UV) radiation resistance was determined in a collection of Pseudomonas syringae pv. syringae strains isolated from mango. The potential role of these plasmids in UV tolerance and ecological fitness in the mango phyllosphere was also evaluated. Nearly all of the 62-kb plasmids present in the P. syringae pv. syringae strains hybridized with a rulAB probe, but these 62-kb plasmids showed differences in restriction patterns. In vitro assays of tolerance to UV radiation of P. syringae pv. syringae strains showed a higher survival of the strains harboring the 62-kb plasmids compared to strains lacking plasmids when exposed to UVC or UVA+B fractions. Similar results were observed when transconjugants harboring the 62-kb plasmid were tested. Survival assays were carried out under field conditions, and a higher survival of P. syringae pv. syringae strains harboring 62-kb plasmids under direct solar radiation on the adaxial surface of leaves was also observed. When the assays were carried out in shady areas or on the abaxial surface of leaves, survival time was comparable for all the assayed strains, whether or not they contained a 62-kb plasmid hybridizing to rulAB. Our results indicate that P. syringae pv. syringae strains harboring 62-kb plasmids show an increase in ecological fitness when colonizing the mango phyllosphere.
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Affiliation(s)
- F M Cazorla
- Grupo de Microbiología y Patología Vegetal-Unidad Asociada CSIC, Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071, Málaga, Spain
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15
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Gunasekera TS, Paul ND. Ecological impact of solar ultraviolet-B (UV-B: 320?290�nm) radiation on Corynebacterium aquaticum and Xanthomonas sp. colonization on tea phyllosphere in relation to blister blight disease incidence in the field. Lett Appl Microbiol 2007; 44:513-9. [PMID: 17451518 DOI: 10.1111/j.1472-765x.2006.02102.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To assess the effects of solar UV-B radiation on phyllosphere bacteria of tea leaves in relation to blister blight disease in the field. METHODS AND RESULTS The effects of UV-B radiation on the phyllosphere microbiology of tea (Camellia sinensis) were studied in contrasting wet and dry seasons at a tropical site. Wavelength-selective filters were used to separate the effects of UV-B from those of other factors. Bacterial populations were quantified in relation to the incidence of blister blight disease. Attenuation of UV-B increased the survival of Xanthomonas sp. when populations were not water limited, and increased the incidence of blister blight, but had no effect on Corynebacterium aquaticum. CONCLUSIONS The effects of solar UV-B on phyllosphere bacteria were substantial but depended on both species and interactions with other environmental variables. Xanthomonas sp. was more sensitive to UV-B than C. aquaticum, but this did not result in differences in population density under high radiation conditions (dry season), but only in the wet season when other factors were not limiting. SIGNIFICANCE AND IMPACT OF THE STUDY The role of UV-B on leaf surface microbiology in the tropics is marked but depends on other conditions, and the contrasting UV-B responses of different organisms can be masked by other limiting factors.
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Affiliation(s)
- T S Gunasekera
- Division of Biological Sciences, Lancaster University, Lancaster, UK.
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