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Maguvu TE, Frias RJ, Hernandez-Rosas AI, Holtz BA, Niederholzer FJA, Duncan RA, Yaghmour MA, Culumber CM, Gordon PE, Vieira FCF, Rolshausen PE, Adaskaveg JE, Burbank LP, Lindow SE, Trouillas FP. Phylogenomic analyses and comparative genomics of Pseudomonas syringae associated with almond (Prunus dulcis) in California. PLoS One 2024; 19:e0297867. [PMID: 38603730 PMCID: PMC11008872 DOI: 10.1371/journal.pone.0297867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/10/2024] [Indexed: 04/13/2024] Open
Abstract
We sequenced and comprehensively analysed the genomic architecture of 98 fluorescent pseudomonads isolated from different symptomatic and asymptomatic tissues of almond and a few other Prunus spp. Phylogenomic analyses, genome mining, field pathogenicity tests, and in vitro ice nucleation and antibiotic sensitivity tests were integrated to improve knowledge of the biology and management of bacterial blast and bacterial canker of almond. We identified Pseudomonas syringae pv. syringae, P. cerasi, and P. viridiflava as almond canker pathogens. P. syringae pv. syringae caused both canker and foliar (blast) symptoms. In contrast, P. cerasi and P. viridiflava only caused cankers, and P. viridiflava appeared to be a weak pathogen of almond. Isolates belonging to P. syringae pv. syringae were the most frequently isolated among the pathogenic species/pathovars, composing 75% of all pathogenic isolates. P. cerasi and P. viridiflava isolates composed 8.3 and 16.7% of the pathogenic isolates, respectively. Laboratory leaf infiltration bioassays produced results distinct from experiments in the field with both P. cerasi and P. syringae pv. syringae, causing significant necrosis and browning of detached leaves, whereas P. viridiflava conferred moderate effects. Genome mining revealed the absence of key epiphytic fitness-related genes in P. cerasi and P. viridiflava genomic sequences, which could explain the contrasting field and laboratory bioassay results. P. syringae pv. syringae and P. cerasi isolates harboured the ice nucleation protein, which correlated with the ice nucleation phenotype. Results of sensitivity tests to copper and kasugamycin showed a strong linkage to putative resistance genes. Isolates harbouring the ctpV gene showed resistance to copper up to 600 μg/ml. In contrast, isolates without the ctpV gene could not grow on nutrient agar amended with 200 μg/ml copper, suggesting ctpV can be used to phenotype copper resistance. All isolates were sensitive to kasugamycin at the label-recommended rate of 100μg/ml.
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Affiliation(s)
- Tawanda E. Maguvu
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States of America
- Kearney Agricultural Research and Extension Center, Parlier, CA, United States of America
| | - Rosa J. Frias
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States of America
| | | | - Brent A. Holtz
- University of California Cooperative Extension, CA, United States of America
| | | | - Roger A. Duncan
- University of California Cooperative Extension, CA, United States of America
| | | | | | - Phoebe E. Gordon
- University of California Cooperative Extension, CA, United States of America
| | - Flavia C. F. Vieira
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, CA, United States of America
| | - Philippe E. Rolshausen
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, CA, United States of America
| | - James E. Adaskaveg
- Department of Plant Pathology and Microbiology, University of California, Riverside, Riverside, CA, United States of America
| | - Lindsey P. Burbank
- U.S. Department of Agriculture, Agricultural Research Service, Parlier, CA, United States of America
| | - Steven E. Lindow
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States of America
| | - Florent P. Trouillas
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States of America
- Kearney Agricultural Research and Extension Center, Parlier, CA, United States of America
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2
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Lipps SM, Castell-Miller C, Morris CE, Ishii S, Samac DA. Diversity of Strains in the Pseudomonas syringae Complex Causing Bacterial Stem Blight of Alfalfa ( Medicago sativa) in the United States. PHYTOPATHOLOGY 2024; 114:802-812. [PMID: 37913751 DOI: 10.1094/phyto-02-23-0059-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Alfalfa growers in the Intermountain West of the United States have recently seen an increased incidence in bacterial stem blight (BSB), which can result in significant herbage yield losses from the first harvest. BSB has been attributed to Pseudomonas syringae pv. syringae and P. viridiflava; however, little is known about the genetic diversity and pathogenicity of these bacteria or their interaction with alfalfa plants. Here, we present a comprehensive phylogenetic and phenotypic analysis of P. syringae and P. viridiflava strains causing BSB on alfalfa. A multilocus sequence analysis found that they grouped exclusively with P. syringae PG2b and P. viridiflava PG7a. Alfalfa symptoms caused by both bacterial groups were indistinguishable, although there was a large range in mean disease scores for individual strains. Overall, PG2b strains incited significantly greater disease scores than those caused by PG7a strains. Inoculated plants showed browning in the xylem and collapse of epidermal and pith parenchyma cells. Inoculation with a mixture of PG2b and PG7a strains did not result in synergistic activity. The populations of PG2b and PG7a strains were genetically diverse within their clades and did not group by location or haplotype. The PG2b strains had genes for production of the phytotoxin coronatine, which is unusual in PG2b strains. The results indicate that both pathogens are well established on alfalfa across a wide geographic range and that a recent introduction or evolution of more aggressive strains as the basis for emergence of the disease is unlikely.
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Affiliation(s)
- Savana M Lipps
- Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, U.S.A
| | | | | | - Satoshi Ishii
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, U.S.A
- BioTechnology Institute, University of Minnesota, St. Paul, MN 55108, U.S.A
| | - Deborah A Samac
- Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, U.S.A
- U.S. Department of Agriculture-Agricultural Research Service-Plant Science Research Unit, St. Paul, MN 55108, U.S.A
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3
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Duque-Jaramillo A, Ulmer N, Alseekh S, Bezrukov I, Fernie AR, Skirycz A, Karasov TL, Weigel D. The genetic and physiological basis of Arabidopsis thaliana tolerance to Pseudomonas viridiflava. THE NEW PHYTOLOGIST 2023; 240:1961-1975. [PMID: 37667565 DOI: 10.1111/nph.19241] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/15/2023] [Indexed: 09/06/2023]
Abstract
The opportunistic pathogen Pseudomonas viridiflava colonizes > 50 agricultural crop species and is the most common Pseudomonas in the phyllosphere of European Arabidopsis thaliana populations. Belonging to the P. syringae complex, it is genetically and phenotypically distinct from well-characterized P. syringae sensu stricto. Despite its prevalence, we lack knowledge of how A. thaliana responds to its native isolates at the molecular level. Here, we characterize the host response in an A. thaliana - P. viridiflava pathosystem. We measured host and pathogen growth in axenic infections and used immune mutants, transcriptomics, and metabolomics to determine defense pathways influencing susceptibility to P. viridiflava infection. Infection with P. viridiflava increased jasmonic acid (JA) levels and the expression of ethylene defense pathway marker genes. The immune response in a susceptible host accession was delayed compared with a tolerant one. Mechanical injury rescued susceptibility, consistent with an involvement of JA. The JA/ethylene pathway is important for suppression of P. viridiflava, yet suppression capacity varies between accessions. Our results shed light on how A. thaliana can suppress the ever-present P. viridiflava, but further studies are needed to understand how P. viridiflava evades this suppression to spread broadly across A. thaliana populations.
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Affiliation(s)
| | - Nina Ulmer
- Max Planck Institute for Biology Tübingen, Tübingen, 72076, Germany
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany
| | - Ilja Bezrukov
- Max Planck Institute for Biology Tübingen, Tübingen, 72076, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany
| | - Aleksandra Skirycz
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, 14476, Germany
- Boyce Thompson Institute, Cornell University, Ithaca, 14850, USA
| | - Talia L Karasov
- Max Planck Institute for Biology Tübingen, Tübingen, 72076, Germany
- School of Biological Sciences, University of Utah, Salt Lake City, 84112, USA
| | - Detlef Weigel
- Max Planck Institute for Biology Tübingen, Tübingen, 72076, Germany
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, 72074, Germany
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4
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Ramírez N, Sigurbjörnsdóttir MA, Monteil C, Berge O, Heiðmarsson S, Jackson RW, Morris C, Vilhelmsson O. Pseudomonas syringae isolated in lichens for the first time: Unveiling Peltigera genus as the exclusive host. Environ Microbiol 2023; 25:3502-3511. [PMID: 37658725 DOI: 10.1111/1462-2920.16490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 08/01/2023] [Indexed: 09/03/2023]
Abstract
Pseudomonas syringae is a bacterial complex that is widespread through a range of environments, typically associated with plants where it can be pathogenic, but also found in non-plant environments such as clouds, precipitation, and surface waters. Understanding its distribution within the environment, and the habitats it occupies, is important for examining its evolution and understanding behaviours. After a recent study found P. syringae living among a range of vascular plant species in Iceland, we questioned whether lichens could harbour P. syringae. Sixteen different species of lichens were sampled all over Iceland, but only one lichen genus, Peltigera, was found to consistently harbour P. syringae. Phylogenetic analyses of P. syringae from 10 sampling points where lichen, tracheophyte, and/or moss were simultaneously collected showed significant differences between sampling points, but not between different plants and lichens from the same point. Furthermore, while there were similarities in the P. syringae population in tracheophytes and Peltigera, the densities in Peltigera thalli were lower than in moss and tracheophyte samples. This discovery suggests P. syringae strains can localize and survive in organisms beyond higher plants, and thus reveals opportunities for studying their influence on P. syringae evolution.
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Affiliation(s)
- Natalia Ramírez
- Department of Natural Resource Sciences, University of Akureyri, Akureyri, Iceland
| | | | - Cecile Monteil
- INRA, UR0407 Pathologie Vegétale, Montfavet Cedex, France
| | - Odile Berge
- INRA, UR0407 Pathologie Vegétale, Montfavet Cedex, France
| | | | - Robert W Jackson
- School of Biosciences and Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK
| | - Cindy Morris
- INRA, UR0407 Pathologie Vegétale, Montfavet Cedex, France
| | - Oddur Vilhelmsson
- Department of Natural Resource Sciences, University of Akureyri, Akureyri, Iceland
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Bricout A, Morris CE, Chandeysson C, Duban M, Boistel C, Chataigné G, Lecouturier D, Jacques P, Leclère V, Rochex A. The Diversity of Lipopeptides in the Pseudomonas syringae Complex Parallels Phylogeny and Sheds Light on Structural Diversification during Evolutionary History. Microbiol Spectr 2022; 10:e0145622. [PMID: 36287007 PMCID: PMC9769872 DOI: 10.1128/spectrum.01456-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/12/2022] [Indexed: 01/05/2023] Open
Abstract
Pseudomonas spp. colonize diverse aquatic and terrestrial habitats and produce a wide variety of secondary metabolites, including lipopeptides. However, previous studies have often examined a limited number of lipopeptide-producing strains. In this study, we performed a systematic analysis of lipopeptide production across a wide data set of strains of the Pseudomonas syringae complex (724) by using a combined bioinformatics, mass spectrometry, and phylogenetics approach. The large P. syringae complex, which is composed of 13 phylogroups, is known to produce factins (including syringafactin-like lipopeptides), mycins (including syringomycin-like lipopeptides), and peptins (such as syringopeptins). We found that 80.8% of P. syringae strains produced lipopeptides and that factins were the most frequently produced (by 96% of the producing strains). P. syringae strains were either factin monoproducers or factin, mycin, and peptin coproducers or lipopeptide nonproducers in relation to their phylogenetic group. Our analyses led to the discovery of 42 new lipopeptides, bringing the number of lipopeptides identified in the P. syringae complex to 75. We also highlighted that factins have high structural resemblance and are widely distributed among the P. syringae complex, while mycins and peptins are highly structurally diverse and patchily distributed. IMPORTANCE This study provides an insight into the P. syringae metabolome that emphasizes the high diversity of lipopeptides produced within the P. syringae complex. The production profiles of strains are closely related to their phylogenetic classification, indicating that structural diversification of lipopeptides parallels the phylogeny of this bacterial complex, thereby further illustrating the inherent importance of lipopeptides in the ecology of this group of bacteria throughout its evolutionary history. Furthermore, this overview of P. syringae lipopeptides led us to propose a refined classification that could be extended to the lipopeptides produced by other bacterial groups.
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Affiliation(s)
- Alexandre Bricout
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
- Agence de la transition écologique (ADEME), Angers, France
| | | | | | - Matthieu Duban
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
| | - Corinne Boistel
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
| | - Gabrielle Chataigné
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
| | - Didier Lecouturier
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
| | - Philippe Jacques
- Université de Liège, Université de Lille, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, TERRA Teaching and Research Centre, Gembloux Agro-Bio Tech, Gembloux, Belgium
| | - Valérie Leclère
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
| | - Alice Rochex
- Université de Lille, Université de Liège, UMRt BioEcoAgro 1158-INRAE, Métabolites Secondaires d’Origine Microbienne, Charles Viollette Institute, Lille, France
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6
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Beltrán F, Correa F, Moreno Z, Otarola J, Sagredo B, Millas P. First report of Pseudomonas viridiflava causing fruit rot on sweet cherry trees in Chile. PLANT DISEASE 2022; 107:1216. [PMID: 36167514 DOI: 10.1094/pdis-07-22-1638-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Chile is an important producers of sweet cherry (Prunus avium L.), with a total of 356,385 t exported in the 2021 to 2022 season. The production area includes most of the country's regions. Bacterial samples were isolated in 2017 and 2018 from 18 commercial sweet cherry orchards with canker disease. From one of this samples collected in the spring of 2018, was isolated the strain A2M176 from buds of trees that presented canker and gomosis in Malloa locality (34°23' 46'' S 71°01' 39'' W). The strain produced fluorescent pigment on King's B agar medium. Is oxidase and arginine dihydrolase negative, potato soft rot positive and showed a slight degree of tobacco hypersensitivity. It was able to growth up to 0.8 mM (200 ppm) of CuSO4·5H2O. The strain A2M176 was deposited in the Colección Chilena de Recursos Genéticos Microbianos (CChRGM) under the no. RGM 3342. The DNA of this strain was extracted from a pure culture using silica spin columns (Epoch Life Science Inc., Sugar Land, USA). The complete DNA was sequenced using HiSeq with 150 bp paired-end at GENEWIZ (New York, USA). Raw data was checked using FASTQC and trimmed with BBDuk. The genome was assembled using Unicycler v0.4.9 with defaulf settings and annotated with Prokaryotic Genome Annotation Pipeline (PGAP) v4.3. The reads and genomes were uploaded to GenBank under the BioProyect no. PRJNA750090, BioSample no. SAMN26870984 and assembly no. GCA_022936465.1. The sequenced genome was compared through Average Nucleotide Identity algorithm (ANI) using FastANI v1.33 to compare with closest complete genome available on NCBI. The strain A2M176 was identified as P. viridiflava with ANI value of 98.06% with the strain p22.E7 (GCF_900585495). Maximum likelihood phylogenetic estimation clustered strain A2M176 with other P. viridiflava strains with 95% bootstrap. The pathogenicity of the strain was tested inoculating immature cherry fruits with a needle with a bacterial suspension (1x108 CFU/ml). The inoculated fruits were placed at room temperature in a humid chamber for 10 d. Soft rot lesions were observed, which appeared at 6 days post-inoculation (DPI). The control fruits treated with sterile water did not show symptoms. Further analyses in the genome of strain A2M176 led to identify genes related to pathogenicity, such as the effector gene avrE and the regulator gen HrpL, suggesting the pathogenic capacity of the strain. Also, there were identify genes of two known Pseudomonas copper resistance mechanisms, the cus and cop operon. These genes were found part of the copABCDns cluster similar to what was observed in Pseudomonas from Mango. Presence of P. viridiflava strains causing fruit rot in P. avium is not surprising, since P. viridiflava has a wide host range and causes a variety of symptoms in different plant parts, including stems, leaves, and blossoms. P. viridiflava represents one of the multiple phylogroups found within the P. syringae species complex. To our knowledge, this is the first report of a strain of P. viridiflava copper resistant causing infection on sweet cherries in Chile.
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Affiliation(s)
- Francisca Beltrán
- Instituto de Investigaciones Agropecuarias (INIA). Avenida Salamanca s/n, Rengo, Chile, Rengo, Chile;
| | - Francisco Correa
- 1Instituto de Investigaciones Agropecuarias (INIA). Avenida Salamanca s/n, Rengo, Chile, Rengo, Chile;
| | - Zoe Moreno
- Instituto de Investigaciones Agropecuarias (INIA). Avenida Salamanca s/n, Rengo, Chile, Rengo, Chile;
| | - Jaime Otarola
- Instituto de Investigaciones Agropecuarias (INIA). Avenida Salamanca s/n, Rengo, Chile, Rengo, Chile;
| | - Boris Sagredo
- Instituto de Investigaciones Agropecuarias (INIA). Avenida Salamanca s/n, Rengo, Chile, Rengo, Chile;
| | - Paz Millas
- Instituto de Investigaciones Agropecuarias Centro Regional Quilamapu, Av. Vicente Méndez 515, Chillan, Diguillín, Chile, 3780000;
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7
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Bundalovic-Torma C, Lonjon F, Desveaux D, Guttman DS. Diversity, Evolution, and Function of Pseudomonas syringae Effectoromes. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:211-236. [PMID: 35537470 DOI: 10.1146/annurev-phyto-021621-121935] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pseudomonas syringae is an evolutionarily diverse bacterial species complex and a preeminent model for the study of plant-pathogen interactions due in part to its remarkably broad host range. A critical feature of P. syringae virulence is the employment of suites of type III secreted effector (T3SE) proteins, which vary widely in composition and function. These effectors act on a variety of plant intracellular targets to promote pathogenesis but can also be avirulence factors when detected by host immune complexes. In this review, we survey the phylogenetic diversity (PD) of the P. syringae effectorome, comprising 70 distinct T3SE families identified to date, and highlight how avoidance of host immune detection has shaped effectorome diversity through functional redundancy, diversification, and horizontal transfer. We present emerging avenues for research and novel insights that can be gained via future investigations of plant-pathogen interactions through the fusion of large-scale interaction screens and phylogenomic approaches.
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Affiliation(s)
| | - Fabien Lonjon
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
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8
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Fernández-Sanz AM, Rodicio MR, González AJ. Biochemical Diversity, Pathogenicity and Phylogenetic Analysis of Pseudomonas viridiflava from Bean and Weeds in Northern Spain. Microorganisms 2022; 10:1542. [PMID: 36013960 PMCID: PMC9412563 DOI: 10.3390/microorganisms10081542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/25/2022] Open
Abstract
Pseudomonas viridiflava was originally reported as a bean pathogen, and subsequently as a wide-host range pathogen affecting numerous plants species. In addition, several authors have reported the epiphytic presence of this bacterium in "non-host plants", which may act as reservoir of P. viridiflava and source of inoculum for crops. A new biotype of this bacterium, showing an atypical LOPAT profile, was found in Asturias, a Northern region of Spain, causing significant damage in beans, kiwifruit, lettuce, and Hebe. In order to investigate the involvement of weeds in bean disease, samples were collected from beans and weeds growing in the same fields. A total of 48 isolates of P. viridiflava were obtained, 39 from weeds and 9 from beans. 48% and 52% of them showed typical (L- O- P+ A- T+) and atypical (L+ O- P v A- T+) LOPAT profiles, and they displayed high biochemical diversity. Regarding virulence factors, the T-PAI and S-PAI pathogenicity islands were found in 29% and 70.8% of the isolates, 81.2% displayed pectinolytic activity on potato slices, and 59% of the weed isolates produced symptoms after inoculation on bean pods. A phylogenetic tree based on concatenated rpoD, gyrB, and gltA sequences separated the strains carrying S-PAI and T-PAI into different clusters, both containing isolates from beans and weeds, and pathogenic as well as non-pathogenic strains. Closely related strains were found in the two hosts, and more than half of the weed isolates proved to be pathogenic in beans. This is consistent with the role of weeds as a reservoir and source of inoculum for bean infection. Detection of P. viridiflava in weeds throughout the year further supports these roles.
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Affiliation(s)
- Ana M. Fernández-Sanz
- Programa de Patología Vegetal, Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Ctra AS-267, PK 19, 33300 Villaviciosa, Spain;
| | - M. Rosario Rodicio
- Área de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo, Julián Clavería 6, 33006 Oviedo, Spain;
| | - Ana J. González
- Programa de Patología Vegetal, Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Ctra AS-267, PK 19, 33300 Villaviciosa, Spain;
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9
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Molecular and Genomic Characterization of the Pseudomonas syringae Phylogroup 4: An Emerging Pathogen of Arabidopsis thaliana and Nicotiana benthamiana. Microorganisms 2022; 10:microorganisms10040707. [PMID: 35456758 PMCID: PMC9030749 DOI: 10.3390/microorganisms10040707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/21/2022] [Indexed: 12/10/2022] Open
Abstract
Environmental fluctuations such as increased temperature, water availability, and air CO2 concentration triggered by climate change influence plant disease dynamics by affecting hosts, pathogens, and their interactions. Here, we describe a newly discovered Pseudomonas syringae strain found in a natural population of Arabidopsis thaliana collected from the southwest of France. This strain, called Psy RAYR-BL, is highly virulent on natural Arabidopsis accessions, Arabidopsis model accession Columbia 0, and tobacco plants. Despite the severe disease phenotype caused by the Psy RAYR-BL strain, we identified a reduced repertoire of putative Type III virulence effectors by genomic sequencing compared to P. syringae pv tomato (Pst) DC3000. Furthermore, hopBJ1Psy is found exclusively on the Psy RAYR-BL genome but not in the Pst DC3000 genome. The plant expression of HopBJ1Psy induces ROS accumulation and cell death. In addition, HopBJ1Psy participates as a virulence factor in this plant-pathogen interaction, likely explaining the severity of the disease symptoms. This research describes the characterization of a newly discovered plant pathogen strain and possible virulence mechanisms underlying the infection process shaped by natural and changing environmental conditions.
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10
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Lipps SM, Samac DA. Pseudomonas viridiflava: An internal outsider of the Pseudomonas syringae species complex. MOLECULAR PLANT PATHOLOGY 2022; 23:3-15. [PMID: 34463014 PMCID: PMC8659605 DOI: 10.1111/mpp.13133] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED Pseudomonas viridiflava is a gram-negative pseudomonad that is phylogenetically placed within the Pseudomonas syringae species complex. P. viridiflava has a wide host range and causes a variety of symptoms in different plant parts, including stems, leaves, and blossoms. Outside of its role as a pathogen, P. viridiflava also exists as an endophyte, epiphyte, and saprophyte. Increased reports of P. viridiflava causing disease on new hosts in recent years coincide with increased research on its genetic variability, virulence, phylogenetics, and phenotypes. There is high variation in its core genome, virulence factors, and phenotypic characteristics. The main virulence factors of this pathogen include the enzyme pectate lyase and virulence genes encoded within one or two pathogenicity islands. The delineation of P. viridiflava in the P. syringae complex has been investigated using several molecular approaches. P. viridiflava comprises its own species, within the complex. While seemingly an outsider to the complex as a whole due to differences in the core genome and virulence genes, low average nucleotide identity to other of P. syringae complex members, and some phenotypic traits, it remains as part of the complex. Defining phylogenetic, phenotypic, and genomic characteristics of P. viridiflava in comparison to other P. syringae members is important to understanding this pathogen and for the development of disease resistance and management practices. TAXONOMY Kingdom Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Family Pseudomonadaceae; Genus Pseudomonas; Species Pseudomonas syringae species complex, Genomospecies 6, Phylogroup 7 and 8. MICROBIOLOGICAL PROPERTIES Gram-negative, fluorescent, aerobic, motile, rod-shaped, oxidase negative, arginine dihydrolase negative, levan production negative (or positive), potato rot positive (or negative), tobacco hypersensitivity positive. GENOME There are two complete genomes, five chromosome-level genomes, and 1,540 genomes composed of multiple scaffolds of P. viridiflava available in the National Center for Biotechnology Information Genome database. The median total length of these assemblies is 5,975,050 bp, the median number of protein coding genes is 5,208, and the median G + C content is 59.3%. DISEASE SYMPTOMS P. viridiflava causes a variety of disease symptoms, including spots, streaks, necrosis, rots, and more in above- and below-ground plant parts on at least 50 hosts. EPIDEMIOLOGY There have been several significant disease outbreaks on field and horticultural crops caused by P. viridiflava since the turn of the century. P. viridiflava has been reported as a pathogen, epiphyte, endophyte, and saprophyte. This species has been isolated from a variety of environmental sources, including asymptomatic wild plants, snow, epilithic biofilms, and icepacks.
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Affiliation(s)
- Savana M. Lipps
- Plant PathologyUniversity of Minnesota Twin CitiesSt PaulMNUSA
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Su Y, Ge Y, Xu Z, Zhang D, Li D. The digestive and reproductive tract microbiotas and their association with body weight in laying hens. Poult Sci 2021; 100:101422. [PMID: 34534851 PMCID: PMC8449050 DOI: 10.1016/j.psj.2021.101422] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 02/07/2023] Open
Abstract
Body weight at the onset of egg production is a major factor influencing hen productivity, as suitable body weight is crucial to laying performance in laying hens. To better understand the association between body weight and microbial community membership and structure in different sites of the digestive and reproductive tracts in chickens, we performed 16S rRNA sequencing surveys and focused on how the microbiota may interact to influence body weight. Our results demonstrated that the microbial community and structure of the digestive and reproductive tracts differed between low and high body weight groups. In particular, we found that the species Pseudomonas viridiflava was negatively associated with body weight in the 3 digestive tract sites, while Bacteroides salanitronis was negatively associated with body weight in the 3 reproductive tract sites; and further in-depth studies are needed to explore their function. These findings will help extend our understanding of the influence of the bird digestive and reproductive tract microbiotas on body weight trait and provide future directions regarding the control of body weight in the production of laying hens.
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Affiliation(s)
- Yuan Su
- Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Yile Ge
- Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhongxian Xu
- Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China
| | - Dejing Zhang
- Novogene Bioinformatics Institute, Beijing 100000, China
| | - Diyan Li
- Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
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Dillon MM, Ruiz-Bedoya T, Bundalovic-Torma C, Guttman KM, Kwak H, Middleton MA, Wang PW, Horuz S, Aysan Y, Guttman DS. Comparative genomic insights into the epidemiology and virulence of plant pathogenic pseudomonads from Turkey. Microb Genom 2021; 7:000585. [PMID: 34227931 PMCID: PMC8477409 DOI: 10.1099/mgen.0.000585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 04/16/2021] [Indexed: 12/31/2022] Open
Abstract
Pseudomonas is a highly diverse genus that includes species that cause disease in both plants and animals. Recently, pathogenic pseudomonads from the Pseudomonas syringae and Pseudomonas fluorescens species complexes have caused significant outbreaks in several agronomically important crops in Turkey, including tomato, citrus, artichoke and melon. We characterized 169 pathogenic Pseudomonas strains associated with recent outbreaks in Turkey via multilocus sequence analysis and whole-genome sequencing, then used comparative and evolutionary genomics to characterize putative virulence mechanisms. Most of the isolates are closely related to other plant pathogens distributed among the primary phylogroups of P. syringae, although there are significant numbers of P. fluorescens isolates, which is a species better known as a rhizosphere-inhabiting plant-growth promoter. We found that all 39 citrus blast pathogens cluster in P. syringae phylogroup 2, although strains isolated from the same host do not cluster monophyletically, with lemon, mandarin orange and sweet orange isolates all being intermixed throughout the phylogroup. In contrast, 20 tomato pith pathogens are found in two independent lineages: one in the P. syringae secondary phylogroups, and the other from the P. fluorescens species complex. These divergent pith necrosis strains lack characteristic virulence factors like the canonical tripartite type III secretion system, large effector repertoires and the ability to synthesize multiple bacterial phytotoxins, suggesting they have alternative molecular mechanisms to cause disease. These findings highlight the complex nature of host specificity among plant pathogenic pseudomonads.
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Affiliation(s)
- Marcus M. Dillon
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Present address: Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada
| | - Tatiana Ruiz-Bedoya
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | | | - Kevin M. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Haejin Kwak
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Maggie A. Middleton
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Pauline W. Wang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
| | - Sumer Horuz
- Department of Plant Protection, Erciyes University, Kayseri, Turkey
| | - Yesim Aysan
- Department of Plant Protection, University of Çukurova, Adana, Turkey
| | - David S. Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada
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Doonan JM, Broberg M, Denman S, McDonald JE. Host-microbiota-insect interactions drive emergent virulence in a complex tree disease. Proc Biol Sci 2020; 287:20200956. [PMID: 32811286 DOI: 10.1098/rspb.2020.0956] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Forest declines caused by climate disturbance, insect pests and microbial pathogens threaten the global landscape, and tree diseases are increasingly attributed to the emergent properties of complex ecological interactions between the host, microbiota and insects. To address this hypothesis, we combined reductionist approaches (single and polyspecies bacterial cultures) with emergentist approaches (bacterial inoculations in an oak infection model with the addition of insect larvae) to unravel the gene expression landscape and symptom severity of host-microbiota-insect interactions in the acute oak decline (AOD) pathosystem. AOD is a complex decline disease characterized by predisposing abiotic factors, inner bark lesions driven by a bacterial pathobiome, and larval galleries of the bark-boring beetle Agrilus biguttatus. We identified expression of key pathogenicity genes in Brenneria goodwinii, the dominant member of the AOD pathobiome, tissue-specific gene expression profiles, cooperation with other bacterial pathobiome members in sugar catabolism, and demonstrated amplification of pathogenic gene expression in the presence of Agrilus larvae. This study highlights the emergent properties of complex host-pathobiota-insect interactions that underlie the pathology of diseases that threaten global forest biomes.
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Affiliation(s)
- James M Doonan
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.,Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, 1958 Frederiksberg C, Denmark
| | - Martin Broberg
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.,Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Sandra Denman
- Forest Research, Centre for Forestry and Climate Change, Alice Holt Lodge, Farnham, Surrey GU10 4LH, UK
| | - James E McDonald
- School of Natural Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK
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Hulin MT, Jackson RW, Harrison RJ, Mansfield JW. Cherry picking by pseudomonads: After a century of research on canker, genomics provides insights into the evolution of pathogenicity towards stone fruits. PLANT PATHOLOGY 2020; 69:962-978. [PMID: 32742023 PMCID: PMC7386918 DOI: 10.1111/ppa.13189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/09/2020] [Accepted: 03/23/2020] [Indexed: 05/10/2023]
Abstract
Bacterial canker disease is a major limiting factor in the growing of cherry and other Prunus species worldwide. At least five distinct clades within the bacterial species complex Pseudomonas syringae are known to be causal agents of the disease. The different pathogens commonly coexist in the field. Reducing canker is a challenging prospect as the efficacy of chemical controls and host resistance may vary against each of the diverse clades involved. Genomic analysis has revealed that the pathogens use a variable repertoire of virulence factors to cause the disease. Significantly, strains of P. syringae pv. syringae possess more genes for toxin biosynthesis and fewer encoding type III effector proteins. There is also a shared pool of key effector genes present on mobile elements such as plasmids and prophages that may have roles in virulence. By contrast, there is evidence that absence or truncation of certain effector genes, such as hopAB, is characteristic of cherry pathogens. Here we highlight how recent research, underpinned by the earlier epidemiological studies, is allowing significant progress in our understanding of the canker pathogens. This fundamental knowledge, combined with emerging insights into host genetics, provides the groundwork for development of precise control measures and informed approaches to breed for disease resistance.
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Affiliation(s)
| | - Robert W. Jackson
- Birmingham Institute of Forest Research (BIFoR), University of BirminghamBirminghamUK
- School of Biosciences, University of BirminghamBirminghamUK
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Bophela KN, Petersen Y, Bull CT, Coutinho TA. Identification of Pseudomonas Isolates Associated With Bacterial Canker of Stone Fruit Trees in the Western Cape, South Africa. PLANT DISEASE 2020; 104:882-892. [PMID: 31935341 DOI: 10.1094/pdis-05-19-1102-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bacterial canker is a common bacterial disease of stone fruit trees. The causal agents responsible for the disease include several pathovars in Pseudomonas syringae sensu lato and newly described Pseudomonas species. Pseudomonad strains were isolated from symptomatic stone fruit trees, namely apricot, peach, and plum trees cultivated in spatially separated orchards in the Western Cape. A polyphasic approach was used to identify and characterize these strains. Using a multilocus sequence typing approach of four housekeeping loci, namely cts, gapA, gyrB, and rpoD, the pseudomonad strains were delineated into two phylogenetic groups within P. syringae sensu lato: P. syringae sensu stricto and Pseudomonas viridiflava. These results were further supported by LOPAT diagnostic assays and analysis of clades in the rep-PCR dendrogram. The pseudomonad strains were pathogenic on both apricot and plum seedlings, indicative of a lack of host specificity between Pseudomonas strains infecting Prunus spp. This is a first report of P. viridiflava isolated from plum trees showing symptoms of bacterial canker. P. viridiflava is considered to be an opportunistic pathogen that causes foliar diseases of vegetable crops, fruit trees, and aromatic herbs, and thus the isolation of pathogenic P. viridiflava from twigs of plum trees showing symptoms of bacterial canker suggests that this bacterial species is a potentially emerging stem canker pathogen of stone fruit trees in South Africa.
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Affiliation(s)
- Khumbuzile N Bophela
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Hatfield 0028, Pretoria, South Africa
| | - Yolanda Petersen
- Crop Development Division, Agricultural Research Council, Infruitec-Nietvoorbij, Stellenbosch 7599, South Africa
| | - Carolee T Bull
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, State College, PA 16801, U.S.A
| | - Teresa A Coutinho
- Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Hatfield 0028, Pretoria, South Africa
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Romero FM, Rossi FR, Gárriz A, Carrasco P, Ruíz OA. A Bacterial Endophyte from Apoplast Fluids Protects Canola Plants from Different Phytopathogens via Antibiosis and Induction of Host Resistance. PHYTOPATHOLOGY 2019; 109:375-383. [PMID: 30156501 DOI: 10.1094/phyto-07-18-0262-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Endophytic bacteria colonize inner plant tissues and thrive at the apoplast, which is considered its main reservoir. Because this niche is the place where the main molecular events take place between beneficial and pathogenic microorganisms, the aim of this work was to characterize culturable endophytic bacteria from apoplastic fluids obtained from field-grown canola leaves and analyze their potential for biological control of diseases caused by Xanthomonas campestris, Sclerotinia sclerotiorum, and Leptosphaeria maculans. Dual-culture analysis indicated that three isolates (Apo8, Apo11, and Apo12) were able to inhibit the growth of all three phytopathogens. Sequencing of the 16S ribosomal RNA and rpoD genes of these isolates revealed that they are closely related to Pseudomonas viridiflava. One of the isolates, Apo11, was able to diminish the propagation of X. campestris in whole-plant assays. At the same time, Apo11 inoculation reduced the necrotic lesions provoked by S. sclerotiorum on canola leaves. This protective effect might be due to the induction of resistance in the host mediated by salicylic and jasmonic acid signaling pathways or the production of compounds with antimicrobial activity. At the same time, Apo11 inoculation promoted canola plant growth. Thus, the isolate characterized in this work has several desirable characteristics, which make it a potential candidate for the formulation of biotechnological products to control plant diseases or promote plant growth.
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Affiliation(s)
- Fernando M Romero
- First, second, third, and fifth authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina; fourth author: Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, València, Spain; and fifth author: Instituto de Fisiología y Recursos Genéticos Vegetales, Instituto Nacional de Tecnología Agropecuaria (IFRGV-INTA), Córdoba, Argentina
| | - Franco R Rossi
- First, second, third, and fifth authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina; fourth author: Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, València, Spain; and fifth author: Instituto de Fisiología y Recursos Genéticos Vegetales, Instituto Nacional de Tecnología Agropecuaria (IFRGV-INTA), Córdoba, Argentina
| | - Andrés Gárriz
- First, second, third, and fifth authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina; fourth author: Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, València, Spain; and fifth author: Instituto de Fisiología y Recursos Genéticos Vegetales, Instituto Nacional de Tecnología Agropecuaria (IFRGV-INTA), Córdoba, Argentina
| | - Pedro Carrasco
- First, second, third, and fifth authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina; fourth author: Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, València, Spain; and fifth author: Instituto de Fisiología y Recursos Genéticos Vegetales, Instituto Nacional de Tecnología Agropecuaria (IFRGV-INTA), Córdoba, Argentina
| | - Oscar A Ruíz
- First, second, third, and fifth authors: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina; fourth author: Departament de Bioquímica i Biologia Molecular, Facultat de Ciències Biològiques, Universitat de València, València, Spain; and fifth author: Instituto de Fisiología y Recursos Genéticos Vegetales, Instituto Nacional de Tecnología Agropecuaria (IFRGV-INTA), Córdoba, Argentina
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Karasov TL, Almario J, Friedemann C, Ding W, Giolai M, Heavens D, Kersten S, Lundberg DS, Neumann M, Regalado J, Neher RA, Kemen E, Weigel D. Arabidopsis thaliana and Pseudomonas Pathogens Exhibit Stable Associations over Evolutionary Timescales. Cell Host Microbe 2018; 24:168-179.e4. [PMID: 30001519 PMCID: PMC6054916 DOI: 10.1016/j.chom.2018.06.011] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/16/2018] [Accepted: 06/21/2018] [Indexed: 11/23/2022]
Abstract
Crop disease outbreaks are often associated with clonal expansions of single pathogenic lineages. To determine whether similar boom-and-bust scenarios hold for wild pathosystems, we carried out a multi-year, multi-site survey of Pseudomonas in its natural host Arabidopsis thaliana. The most common Pseudomonas lineage corresponded to a ubiquitous pathogenic clade. Sequencing of 1,524 genomes revealed this lineage to have diversified approximately 300,000 years ago, containing dozens of genetically identifiable pathogenic sublineages. There is differentiation at the level of both gene content and disease phenotype, although the differentiation may not provide fitness advantages to specific sublineages. The coexistence of sublineages indicates that in contrast to crop systems, no single strain has been able to overtake the studied A. thaliana populations in the recent past. Our results suggest that selective pressures acting on a plant pathogen in wild hosts are likely to be much more complex than those in agricultural systems.
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Affiliation(s)
- Talia L Karasov
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Juliana Almario
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany; Interfaculty Institute of Microbiology and Infection Medicine Tübingen, IMITP, University of Tübingen, 72076 Tübingen, Germany
| | - Claudia Friedemann
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Wei Ding
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Michael Giolai
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany; Earlham Institute, Norwich Research Park Innovation Centre, Colney Lane, Norwich NR4 7UZ, UK
| | - Darren Heavens
- Earlham Institute, Norwich Research Park Innovation Centre, Colney Lane, Norwich NR4 7UZ, UK
| | - Sonja Kersten
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Derek S Lundberg
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Manuela Neumann
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Julian Regalado
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Richard A Neher
- University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Eric Kemen
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany; Interfaculty Institute of Microbiology and Infection Medicine Tübingen, IMITP, University of Tübingen, 72076 Tübingen, Germany
| | - Detlef Weigel
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
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Straub C, Colombi E, Li L, Huang H, Templeton MD, McCann HC, Rainey PB. The ecological genetics ofPseudomonas syringaefrom kiwifruit leaves. Environ Microbiol 2018. [DOI: 10.1111/1462-2920.14092] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christina Straub
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Elena Colombi
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Li Li
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden, Chinese Academy of SciencesWuhan People's Republic of China
| | - Hongwen Huang
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden, Chinese Academy of SciencesWuhan People's Republic of China
- Key Laboratory of Plant Resources Conservation and Sustainable UtilizationSouth China Botanical Garden, Chinese Academy of SciencesGuangzhou People's Republic of China
| | | | - Honour C. McCann
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
| | - Paul B. Rainey
- New Zealand Institute for Advanced Study, Massey UniversityAuckland New Zealand
- Max Planck Institute for Evolutionary Biology, Department of Microbial Population BiologyPlön Germany
- École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris Tech), Laboratoire de Génétique de l'EvolutionParis France
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Abstract
Pseudomonas syringae is one of the best-studied plant pathogens and serves as a model for understanding host-microorganism interactions, bacterial virulence mechanisms and host adaptation of pathogens as well as microbial evolution, ecology and epidemiology. Comparative genomic studies have identified key genomic features that contribute to P. syringae virulence. P. syringae has evolved two main virulence strategies: suppression of host immunity and creation of an aqueous apoplast to form its niche in the phyllosphere. In addition, external environmental conditions such as humidity profoundly influence infection. P. syringae may serve as an excellent model to understand virulence and also of how pathogenic microorganisms integrate environmental conditions and plant microbiota to become ecologically robust and diverse pathogens of the plant kingdom.
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Timilsina S, Minsavage GV, Preston J, Newberry EA, Paret ML, Goss EM, Jones JB, Vallad GE. Pseudomonas floridensis sp. nov., a bacterial pathogen isolated from tomato. Int J Syst Evol Microbiol 2018; 68:64-70. [PMID: 29148362 DOI: 10.1099/ijsem.0.002445] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An unusual fluorescent pseudomonad was isolated from tomato exhibiting leaf spot symptoms similar to bacterial speck. Strains were fluorescent, oxidase- and arginine-dihydrolase-negative, elicited a hypersensitive reaction on tobacco and produced a soft rot on potato slices. However, the strains produced an unusual yellow, mucoid growth on media containing 5 % sucrose that is not typical of levan. Based on multilocus sequence analysis using 16S rRNA, gap1, gltA, gyrB and rpoD, these strains formed a distinct phylogenetic group in the genus Pseudomonas and were most closely related to Pseudomonas viridiflava within the Pseudomonassyringae complex. Whole-genome comparisons, using average nucleotide identity based on blast, of representative strain GEV388T and publicly available genomes representing the genus Pseudomonas revealed phylogroup 7 P. viridiflava strain UASW0038 and P. viridiflava type strain ICMP 2848T as the closest relatives with 86.59 and 86.56 % nucleotide identity, respectively. In silico DNA-DNA hybridization using the genome-to-genome distance calculation method estimated 31.1 % DNA relatedness between GEV388T and P. viridiflava ATCC 13223T, strongly suggesting the strains are representatives of different species. These results together with Biolog GEN III tests, fatty acid methyl ester profiles and phylogenetic analysis using 16S rRNA and multiple housekeeping gene sequences demonstrated that this group represents a novel species member of the genus Pseudomonas. The name Pseudomonas floridensis sp. nov. is proposed with GEV388T (=LMG 30013T=ATCC TSD-90T) as the type strain.
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Affiliation(s)
- Sujan Timilsina
- Deparment of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
- Gulf Coast Research and Education Center, University of Florida, Gainesville, FL 32611, USA
| | - Gerald V Minsavage
- Deparment of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - James Preston
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Eric A Newberry
- Deparment of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Matthews L Paret
- North Florida Research and Education Center, University of Florida, Quincy, FL 32251, USA
| | - Erica M Goss
- Deparment of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
| | - Jeffrey B Jones
- Deparment of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Gary E Vallad
- Gulf Coast Research and Education Center, University of Florida, Gainesville, FL 32611, USA
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Comparative genome analysis of the vineyard weed endophyte Pseudomonas viridiflava CDRTc14 showing selective herbicidal activity. Sci Rep 2017; 7:17336. [PMID: 29229911 PMCID: PMC5725424 DOI: 10.1038/s41598-017-16495-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/13/2017] [Indexed: 12/17/2022] Open
Abstract
Microbes produce a variety of secondary metabolites to be explored for herbicidal activities. We investigated an endophyte Pseudomonas viridiflava CDRTc14, which impacted growth of its host Lepidium draba L., to better understand the possible genetic determinants for herbicidal and host-interaction traits. Inoculation tests with a variety of target plants revealed that CDRTc14 shows plant-specific effects ranging from beneficial to negative. Its herbicidal effect appeared to be dose-dependent and resembled phenotypically the germination arrest factor of Pseudomonas fluorescens WH6. CDRTc14 shares 183 genes with the herbicidal strain WH6 but the formylaminooxyvinylglycine (FVG) biosynthetic genes responsible for germination arrest of WH6 was not detected. CDRTc14 showed phosphate solubilizing ability, indole acetic acid and siderophores production in vitro and harbors genes for these functions. Moreover, genes for quorum sensing, hydrogen cyanide and ACC deaminase production were also found in this strain. Although, CDRTc14 is related to plant pathogens, we neither found a complete pathogenicity island in the genome, nor pathogenicity symptoms on susceptible plant species upon CDRTc14 inoculation. Comparison with other related genomes showed several unique genes involved in abiotic stress tolerance in CDRTc14 like genes responsible for heavy metal and herbicide resistance indicating recent adaptation to plant protection measures applied in vineyards.
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Gomila M, Busquets A, Mulet M, García-Valdés E, Lalucat J. Clarification of Taxonomic Status within the Pseudomonas syringae Species Group Based on a Phylogenomic Analysis. Front Microbiol 2017; 8:2422. [PMID: 29270162 PMCID: PMC5725466 DOI: 10.3389/fmicb.2017.02422] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 11/22/2017] [Indexed: 11/13/2022] Open
Abstract
The Pseudomonas syringae phylogenetic group comprises 15 recognized bacterial species and more than 60 pathovars. The classification and identification of strains is relevant for practical reasons but also for understanding the epidemiology and ecology of this group of plant pathogenic bacteria. Genome-based taxonomic analyses have been introduced recently to clarify the taxonomy of the whole genus. A set of 139 draft and complete genome sequences of strains belonging to all species of the P. syringae group available in public databases were analyzed, together with the genomes of closely related species used as outgroups. Comparative genomics based on the genome sequences of the species type strains in the group allowed the delineation of phylogenomic species and demonstrated that a high proportion of strains included in the study are misclassified. Furthermore, representatives of at least 7 putative novel species were detected. It was also confirmed that P. ficuserectae, P. meliae, and P. savastanoi are later synonyms of P. amygdali and that “P. coronafaciens” should be revived as a nomenspecies.
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Affiliation(s)
- Margarita Gomila
- Microbiology, Department of Biology, Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Antonio Busquets
- Microbiology, Department of Biology, Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Magdalena Mulet
- Microbiology, Department of Biology, Universitat de les Illes Balears, Palma de Mallorca, Spain
| | - Elena García-Valdés
- Microbiology, Department of Biology, Universitat de les Illes Balears, Palma de Mallorca, Spain.,Institut Mediterrani d'Estudis Avançats (Consejo Superior de Investigaciones Científicas-Universidad de las Islas Baleares), Palma de Mallorca, Spain
| | - Jorge Lalucat
- Microbiology, Department of Biology, Universitat de les Illes Balears, Palma de Mallorca, Spain.,Institut Mediterrani d'Estudis Avançats (Consejo Superior de Investigaciones Científicas-Universidad de las Islas Baleares), Palma de Mallorca, Spain
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23
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Karasov TL, Barrett L, Hershberg R, Bergelson J. Similar levels of gene content variation observed for Pseudomonas syringae populations extracted from single and multiple host species. PLoS One 2017; 12:e0184195. [PMID: 28880925 PMCID: PMC5589212 DOI: 10.1371/journal.pone.0184195] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/18/2017] [Indexed: 12/22/2022] Open
Abstract
Bacterial strains of the same species collected from different hosts frequently exhibit differences in gene content. In the ubiquitous plant pathogen Pseudomonas syringae, more than 30% of genes encoded by each strain are not conserved among strains colonizing other host species. Although they are often implicated in host specificity, the role of this large fraction of the genome in host-specific adaptation is largely unexplored. Here, we sought to relate variation in gene content between strains infecting different species to variation that persists between strains on the same host. We fully sequenced a collection of P. syringae strains collected from wild Arabidopsis thaliana populations in the Midwestern United States. We then compared patterns of variation observed in gene content within these A. thaliana-isolated strains to previously published P. syringae sequence from strains collected on a diversity of crop species. We find that strains collected from the same host, A. thaliana, differ in gene content by 21%, 2/3 the level of gene content variation observed across strains collected from different hosts. Furthermore, the frequency with which specific genes are present among strains collected within the same host and among strains collected from different hosts is highly correlated. This implies that most gene content variation is maintained irrespective of host association. At the same time, we identify specific genes whose presence is important for P. syringae's ability to flourish within A. thaliana. Specifically, the A. thaliana strains uniquely share a genomic island encoding toxins active against plants and surrounding microbes, suggesting a role for microbe-microbe interactions in dictating the abundance within this host. Overall, our results demonstrate that while variation in the presence of specific genes can affect the success of a pathogen within its host, the majority of gene content variation is not strongly associated with patterns of host use.
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Affiliation(s)
- Talia L. Karasov
- Committee On Genetics Genomics & Systems Biology, University of Chicago, Chicago, Illinois, United States of America
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
| | - Luke Barrett
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
- CSIRO Agriculture, Canberra, ACT 2601, Australia
| | - Ruth Hershberg
- Department of Genetics, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Joy Bergelson
- Committee On Genetics Genomics & Systems Biology, University of Chicago, Chicago, Illinois, United States of America
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois, United States of America
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Complete Genome Sequence of Pseudomonas viridiflava CFBP 1590, Isolated from Diseased Cherry in France. GENOME ANNOUNCEMENTS 2017; 5:5/30/e00662-17. [PMID: 28751394 PMCID: PMC5532832 DOI: 10.1128/genomea.00662-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pseudomonas viridiflava causes foliar and stem necrosis, as well as stem and root rot on a wide range of plants. We report here the first complete genome of a P. viridiflava strain, isolated from diseased tissue of a cherry tree.
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25
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Pseudomonas caspiana sp. nov., a citrus pathogen in the Pseudomonas syringae phylogenetic group. Syst Appl Microbiol 2017; 40:266-273. [PMID: 28552245 DOI: 10.1016/j.syapm.2017.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 04/12/2017] [Accepted: 04/18/2017] [Indexed: 01/27/2023]
Abstract
In a screening by multilocus sequence analysis of Pseudomonas strains isolated from diverse origins, 4 phylogenetically closely related strains (FBF58, FBF102T, FBF103, and FBF122) formed a well-defined cluster in the Pseudomonas syringae phylogenetic group. The strains were isolated from citrus orchards in northern Iran with disease symptoms in the leaves and stems and its pathogenicity against citrus plants was demonstrated. The whole genome of the type strain of the proposed new species (FBF102T=CECT 9164T=CCUG 69273T) was sequenced and characterized. Comparative genomics with the 14 known Pseudomonas species type strains of the P. syringae phylogenetic group demonstrated that this strain belonged to a new genomic species, different from the species described thus far. Genome analysis detected genes predicted to be involved in pathogenesis, such as an atypical type 3 secretion system and two type 6 secretion systems, together with effectors and virulence factors. A polyphasic taxonomic characterization demonstrated that the 4 plant pathogenic strains represented a new species, for which the name Pseudomonas caspiana sp. nov. is proposed.
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26
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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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27
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Samad A, Trognitz F, Antonielli L, Compant S, Sessitsch A. High-Quality Draft Genome Sequence of an Endophytic Pseudomonas viridiflava Strain with Herbicidal Properties against Its Host, the Weed Lepidium draba L. GENOME ANNOUNCEMENTS 2016; 4:e01170-16. [PMID: 27795282 PMCID: PMC5073269 DOI: 10.1128/genomea.01170-16] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 08/31/2016] [Indexed: 11/20/2022]
Abstract
Here, we report the draft genome sequence of Pseudomonas viridiflava strain CDRTc14 a pectinolytic bacterium showing herbicidal activity, isolated from the root of Lepidium draba L. growing as a weed in an Austrian vineyard. The availability of this genome sequence allows us to investigate the genetic basis of plant-microbe interactions.
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Affiliation(s)
- Abdul Samad
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Tulln, Austria
| | - Friederike Trognitz
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Tulln, Austria
| | - Livio Antonielli
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Tulln, Austria
| | - Stéphane Compant
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Tulln, Austria
| | - Angela Sessitsch
- AIT Austrian Institute of Technology GmbH, Bioresources Unit, Tulln, Austria
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28
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Baltrus DA. Divorcing Strain Classification from Species Names. Trends Microbiol 2016; 24:431-439. [PMID: 26947794 DOI: 10.1016/j.tim.2016.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/29/2016] [Accepted: 02/04/2016] [Indexed: 02/01/2023]
Abstract
Confusion about strain classification and nomenclature permeates modern microbiology. Although taxonomists have traditionally acted as gatekeepers of order, the numbers of, and speed at which, new strains are identified has outpaced the opportunity for professional classification for many lineages. Furthermore, the growth of bioinformatics and database-fueled investigations have placed metadata curation in the hands of researchers with little taxonomic experience. Here I describe practical challenges facing modern microbial taxonomy, provide an overview of complexities of classification for environmentally ubiquitous taxa like Pseudomonas syringae, and emphasize that classification can be independent of nomenclature. A move toward implementation of relational classification schemes based on inherent properties of whole genomes could provide sorely needed continuity in how strains are referenced across manuscripts and data sets.
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Affiliation(s)
- David A Baltrus
- School of Plant Sciences, University of Arizona, Tucson, AZ, USA.
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29
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Borschinger B, Bartoli C, Chandeysson C, Guilbaud C, Parisi L, Bourgeay JF, Buisson E, Morris CE. A set of PCRs for rapid identification and characterization of Pseudomonas syringae phylogroups. J Appl Microbiol 2016; 120:714-23. [PMID: 26661140 DOI: 10.1111/jam.13017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/29/2015] [Accepted: 11/26/2015] [Indexed: 12/13/2022]
Abstract
AIMS The aim of this study was to develop a rapid PCR-based method for the specific detection of individual phylogroups of the Pseudomonas syringae complex. METHODS AND RESULTS Seven primer pairs were developed by analysing whole genomes of 54 Ps. syringae strains. The specificity and sensitivity of these primer pairs were assessed on 236 strains from a large and comprehensive Ps. syringae collection. The method was also validated by characterizing the phylogenetic diversity of 174 putative Ps. syringae isolates from kiwifruit and apricot orchards of southeastern France. CONCLUSION Our PCR-based method allows for the detection and characterization of nine of the 13 Ps. syringae phylogroups (phylogroups 1, 2, 3, 4, 7, 8, 9, 10 and 13). SIGNIFICANCE AND IMPACT OF THE STUDY To date, phylogenetic affiliation within the Ps. syringae complex was only possible by sequencing housekeeping genes. Here, we propose a rapid PCR-based method for the detection of specific phylogroups of the Ps. syringae complex. Furthermore, for the first time we reveal the presence of Ps. syringae strains belonging to phylogroups 10 and 13 as epiphytes on plants, whereas they had previously only been observed in aquatic habitats.
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Affiliation(s)
- B Borschinger
- Unité de Pathologie Végétale, INRA, Montfavet, France.,IMBE, Université d'Avignon et des Pays de Vaucluse, UMR CNRS IRD Aix Marseille Université, Avignon, France
| | - C Bartoli
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, Castanet-Tolosan, France.,Laboratoire des Interactions Plantes-Microorganismes (LIPM), CNRS, Castanet-Tolosan, France
| | - C Chandeysson
- Unité de Pathologie Végétale, INRA, Montfavet, France
| | - C Guilbaud
- Unité de Pathologie Végétale, INRA, Montfavet, France
| | - L Parisi
- Unité de Pathologie Végétale, INRA, Montfavet, France
| | - J F Bourgeay
- Unité de Pathologie Végétale, INRA, Montfavet, France
| | - E Buisson
- IMBE, Université d'Avignon et des Pays de Vaucluse, UMR CNRS IRD Aix Marseille Université, Avignon, France
| | - C E Morris
- Unité de Pathologie Végétale, INRA, Montfavet, France
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30
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Guilbaud C, Morris CE, Barakat M, Ortet P, Berge O. Isolation and identification of Pseudomonas syringae facilitated by a PCR targeting the whole P. syringae group. FEMS Microbiol Ecol 2015; 92:fiv146. [PMID: 26610434 DOI: 10.1093/femsec/fiv146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2015] [Indexed: 11/13/2022] Open
Abstract
We present a reliable PCR-based method to avoid the biases related to identification based on the conventional phenotypes currently used in the identification of Pseudomonas syringae sensu lato, a ubiquitous environmental bacterium including plant pathogens. We identified a DNA target suitable for this purpose by applying a comparative genomic pipeline to Pseudomonas genomes. We designed primers and developed PCR conditions that led to a clean and strong PCR product from 97% of the 185 strains of P. syringae strains tested and gave a clear negative result for the 31 non-P. syringae strains tested. The sensitivity of standard PCR was determined with pure strains to be 10(6) bacteria mL(-1) or 0.4 ng of DNA μL(-1). Sensitivity could be improved with the touchdown method. The new PCR-assisted isolation of P. syringae was efficient when deployed on an environmental sample of river water as compared to the isolation based on phenotypes. This innovation eliminates the need for extensive expertise in isolating P. syringae colonies, was simpler, faster and very reliable. It will facilitate discovery of more diversity of P. syringae and research on emergence, dispersion and evolution to understand the varied functions of this environmental bacterium.
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Affiliation(s)
| | - Cindy E Morris
- INRA, UR0407 Pathologie Végétale, F-84143 Montfavet cedex, France
| | - Mohamed Barakat
- CEA, IBEB, Lab Ecol Microb Rhizosphere and Environ Extrem, Saint-Paul-lez-Durance, F-13108, France CNRS, UMR 7265 Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, F-13108, France Aix Marseille Université, BVME UMR7265, Marseille, F-13284, France
| | - Philippe Ortet
- CEA, IBEB, Lab Ecol Microb Rhizosphere and Environ Extrem, Saint-Paul-lez-Durance, F-13108, France CNRS, UMR 7265 Biol Veget and Microbiol Environ, Saint-Paul-lez-Durance, F-13108, France Aix Marseille Université, BVME UMR7265, Marseille, F-13284, France
| | - Odile Berge
- INRA, UR0407 Pathologie Végétale, F-84143 Montfavet cedex, France
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Bartoli C, Lamichhane JR, Berge O, Varvaro L, Morris CE. Mutability in Pseudomonas viridiflava as a programmed balance between antibiotic resistance and pathogenicity. MOLECULAR PLANT PATHOLOGY 2015; 16:860-9. [PMID: 25649542 PMCID: PMC6638476 DOI: 10.1111/mpp.12243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mutable bacterial cells are defective in their DNA repair system and often have a phenotype different from that of their wild-type counterparts. In human bacterial pathogens, the mutable and hypermutable phenotypes are often associated with general antibiotic resistance. Here, we quantified the occurrence of mutable cells in Pseudomonas viridiflava, a phytopathogenic bacterium in the P. syringae complex with a broad host range and capacity to live as a saprophyte. Two phenotypic variants (transparent and mucoid) were produced by this bacterium. The transparent variant had a mutator phenotype, showed general antibiotic resistance and could not induce disease on the plant species tested (bean). In contrast, the mucoid variant did not display mutability or resistance to antibiotics and was capable of inducing disease on bean. Both the transparent and mucoid variants were less fit when grown in vitro, whereas, in planta, both of the variants and wild-types attained similar population densities. Given the importance of the methyl-directed mismatch repair system (MMR) in the occurrence of mutable and hypermutable cells in human bacterial pathogens, we investigated whether mutations in mut genes were associated with mutator transparent cells in P. viridiflava. Our results showed no mutations in MMR genes in any of the P. viridiflava cells tested. Here, we report that a high mutation rate and antibiotic resistance are inversely correlated with pathogenicity in P. viridiflava, but are not associated with mutations in MMR. In addition, P. viridiflava variants differ from variants produced by other phytopathogenic bacteria in the absence of reversion to the wild-type phenotype.
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Affiliation(s)
- Claudia Bartoli
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE), Tuscia University, 01100, Viterbo, Italy
- INRA, UR0407 Pathologie Végétale, F-84143, Montfavet cedex, France
| | - Jay Ram Lamichhane
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE), Tuscia University, 01100, Viterbo, Italy
- INRA, UR0407 Pathologie Végétale, F-84143, Montfavet cedex, France
| | - Odile Berge
- INRA, UR0407 Pathologie Végétale, F-84143, Montfavet cedex, France
| | - Leonardo Varvaro
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE), Tuscia University, 01100, Viterbo, Italy
| | - Cindy E Morris
- INRA, UR0407 Pathologie Végétale, F-84143, Montfavet cedex, France
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32
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A user's guide to a data base of the diversity of Pseudomonas syringae and its application to classifying strains in this phylogenetic complex. PLoS One 2014; 9:e105547. [PMID: 25184292 PMCID: PMC4153583 DOI: 10.1371/journal.pone.0105547] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/22/2014] [Indexed: 11/19/2022] Open
Abstract
The Pseudomonas syringae complex is composed of numerous genetic lineages of strains from both agricultural and environmental habitats including habitats closely linked to the water cycle. The new insights from the discovery of this bacterial species in habitats outside of agricultural contexts per se have led to the revelation of a wide diversity of strains in this complex beyond what was known from agricultural contexts. Here, through Multi Locus Sequence Typing (MLST) of 216 strains, we identified 23 clades within 13 phylogroups among which the seven previously described P. syringae phylogroups were included. The phylogeny of the core genome of 29 strains representing nine phylogroups was similar to the phylogeny obtained with MLST thereby confirming the robustness of MLST-phylogroups. We show that phenotypic traits rarely provide a satisfactory means for classification of strains even if some combinations are highly probable in some phylogroups. We demonstrate that the citrate synthase (cts) housekeeping gene can accurately predict the phylogenetic affiliation for more than 97% of strains tested. We propose a list of cts sequences to be used as a simple tool for quickly and precisely classifying new strains. Finally, our analysis leads to predictions about the diversity of P. syringae that is yet to be discovered. We present here an expandable framework mainly based on cts genetic analysis into which more diversity can be integrated.
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Hockett KL, Nishimura MT, Karlsrud E, Dougherty K, Baltrus DA. Pseudomonas syringae CC1557: a highly virulent strain with an unusually small type III effector repertoire that includes a novel effector. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:923-32. [PMID: 24835253 DOI: 10.1094/mpmi-11-13-0354-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Both type III effector proteins and nonribosomal peptide toxins play important roles for Pseudomonas syringae pathogenicity in host plants, but whether and how these pathways interact to promote infection remains unclear. Genomic evidence from one clade of P. syringae suggests a tradeoff between the total number of type III effector proteins and presence of syringomycin, syringopeptin, and syringolin A toxins. Here, we report the complete genome sequence from P. syringae CC1557, which contains the lowest number of known type III effectors to date and has also acquired genes similar to sequences encoding syringomycin pathways from other strains. We demonstrate that this strain is pathogenic on Nicotiana benthamiana and that both the type III secretion system and a new type III effector, hopBJ1, contribute to pathogenicity. We further demonstrate that activity of HopBJ1 is dependent on residues structurally similar to the catalytic site of Escherichia coli CNF1 toxin. Taken together, our results provide additional support for a negative correlation between type III effector repertoires and the potential to produce syringomycin-like toxins while also highlighting how genomic synteny and bioinformatics can be used to identify and characterize novel virulence proteins.
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