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Tancos MA, Harney-Davila G, Cipollini D. Characterization of Emerging Xanthomonas campestris Isolates on the Nonnative Weed Garlic Mustard ( Alliaria petiolata). PLANT DISEASE 2024; 108:1418-1424. [PMID: 38199962 DOI: 10.1094/pdis-11-23-2391-sr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Nonnative plant infestations provide unique opportunities to investigate pathogen emergence with evolutionarily recent plant introduction events. The widespread distribution of invasive plants and their proximity to genetically related crops highlights the risks of nonnative plants acting as ancillary hosts and fostering microbial recombination and pathogen selection. Garlic mustard (Alliaria petiolata) is a widespread, nonnative cruciferous weed that grows throughout North America and along the forested edges of diverse agricultural fields. The recent identification of a novel Xanthomonas campestris pv. incanae strain isolated from a diseased A. petiolata population led to the current investigation of the distribution and diversity of X. campestris isolates from naturally infected A. petiolata. A total of 14 diseased A. petiolata sites were sampled across three states, leading to the identification of diverse X. campestris pathotypes and genotypes. Pathogenicity assays and multilocus sequence analyses identified pathogenic X. c. pv. incanae and X. c. pv. barbareae strains collected from disparate A. petiolata populations. Moreover, independently collected X. c. pv. incanae strains demonstrated a broad cruciferous host range by infecting cabbage (Brassica oleracea var. capitata), garden stock (Matthiola incana), and the cover crop yellow mustard (Guillenia flavescens). This study highlights the genetic variability and host potential of natural X. campestris populations and the potential risks to Brassica crops via widespread, dense garlic mustard reservoirs.
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Affiliation(s)
- Matthew A Tancos
- Foreign Disease-Weed Science Research Unit, United States Department of Agriculture-Agricultural Research Service, Frederick, MD 21702
| | | | - Don Cipollini
- Department of Biological Sciences, Wright State University, Dayton, OH 45435
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2
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Horton KN, Gassmann W. Greater than the sum of their parts: an overview of the AvrRps4 effector family. FRONTIERS IN PLANT SCIENCE 2024; 15:1400659. [PMID: 38799092 PMCID: PMC11116571 DOI: 10.3389/fpls.2024.1400659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024]
Abstract
Phytopathogenic microbes use secreted effector proteins to increase their virulence in planta. If these effectors or the results of their activity are detected by the plant cell, the plant will mount an immune response which applies evolutionary pressure by reducing growth and success of the pathogen. Bacterial effector proteins in the AvrRps4 family (AvrRps4, HopK1, and XopO) have commonly been used as tools to investigate plant immune components. At the same time, the in planta functions of this family of effectors have yet to be fully characterized. In this minireview we summarize current knowledge about the AvrRps4 effector family with emphasis on properties of the proteins themselves. We hypothesize that the HopK1 C-terminus and the AvrRps4 C-terminus, though unrelated in sequence and structure, are broadly related in functions that counteract plant defense responses.
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Affiliation(s)
| | - Walter Gassmann
- Division of Plant Science and Technology, Bond Life Sciences Center, and Interdisciplinary Plant Group, University of Missouri, Columbia, MO, United States
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3
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Chuang SC, Dobhal S, Alvarez AM, Arif M. Three new species, Xanthomonas hawaiiensis sp. nov., Stenotrophomonas aracearum sp. nov., and Stenotrophomonas oahuensis sp. nov., isolated from the Araceae family. Front Microbiol 2024; 15:1356025. [PMID: 38655077 PMCID: PMC11035887 DOI: 10.3389/fmicb.2024.1356025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/18/2024] [Indexed: 04/26/2024] Open
Abstract
Xanthomonas and Stenotrophomonas are closely related genera in the family Lysobacteraceae. In our previous study of aroid-associated bacterial strains, most strains isolated from anthurium and other aroids were reclassified as X. phaseoli and other Xanthomonas species. However, two strains isolated from Spathiphyllum and Colocasia were phylogenetically distant from other strains in the Xanthomonas clade and two strains isolated from Anthurium clustered within the Stenotrophomonas clade. Phylogenetic trees based on 16S rRNA and nine housekeeping genes placed the former strains with the type strain of X. sacchari from sugarcane and the latter strains with the type strain of S. bentonitica from bentonite. In pairwise comparisons with type strains, the overall genomic relatedness indices required delineation of new species; digital DNA-DNA hybridization and average nucleotide identity values were lower than 70 and 95%, respectively. Hence, three new species are proposed: S. aracearum sp. nov. and S. oahuensis sp. nov. for two strains from anthurium and X. hawaiiensis sp. nov. for the strains from spathiphyllum and colocasia, respectively. The genome size of X. hawaiiensis sp. nov. is ~4.88 Mbp and higher than S. aracearum sp. nov. (4.33 Mbp) and S. oahuensis sp. nov. (4.68 Mbp). Gene content analysis revealed 425 and 576 core genes present in 40 xanthomonads and 25 stenotrophomonads, respectively. The average number of unique genes in Stenotrophomonas spp. was higher than in Xanthomonas spp., implying higher genetic diversity in Stenotrophomonas.
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Affiliation(s)
| | | | | | - Mohammad Arif
- Department of Plant and Environmental Protection Sciences, University of Hawaiʻi at Mānoa, Honolulu, HI, United States
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4
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Pena MM, Bhandari R, Bowers RM, Weis K, Newberry E, Wagner N, Pupko T, Jones JB, Woyke T, Vinatzer BA, Jacques MA, Potnis N. Genetic and Functional Diversity Help Explain Pathogenic, Weakly Pathogenic, and Commensal Lifestyles in the Genus Xanthomonas. Genome Biol Evol 2024; 16:evae074. [PMID: 38648506 PMCID: PMC11032200 DOI: 10.1093/gbe/evae074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2024] [Indexed: 04/25/2024] Open
Abstract
The genus Xanthomonas has been primarily studied for pathogenic interactions with plants. However, besides host and tissue-specific pathogenic strains, this genus also comprises nonpathogenic strains isolated from a broad range of hosts, sometimes in association with pathogenic strains, and other environments, including rainwater. Based on their incapacity or limited capacity to cause symptoms on the host of isolation, nonpathogenic xanthomonads can be further characterized as commensal and weakly pathogenic. This study aimed to understand the diversity and evolution of nonpathogenic xanthomonads compared to their pathogenic counterparts based on their cooccurrence and phylogenetic relationship and to identify genomic traits that form the basis of a life history framework that groups xanthomonads by ecological strategies. We sequenced genomes of 83 strains spanning the genus phylogeny and identified eight novel species, indicating unexplored diversity. While some nonpathogenic species have experienced a recent loss of a type III secretion system, specifically the hrp2 cluster, we observed an apparent lack of association of the hrp2 cluster with lifestyles of diverse species. We performed association analysis on a large data set of 337 Xanthomonas strains to explain how xanthomonads may have established association with the plants across the continuum of lifestyles from commensals to weak pathogens to pathogens. Presence of distinct transcriptional regulators, distinct nutrient utilization and assimilation genes, transcriptional regulators, and chemotaxis genes may explain lifestyle-specific adaptations of xanthomonads.
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Affiliation(s)
- Michelle M Pena
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
- Present address: Department of Plant Pathology, University of Georgia, Tifton, GA, USA
| | - Rishi Bhandari
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Robert M Bowers
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kylie Weis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Eric Newberry
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel Aviv, Israel
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel Aviv, Israel
| | - Jeffrey B Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Tanja Woyke
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Life and Environmental Sciences, University of California Merced, Merced, CA, USA
| | - Boris A Vinatzer
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Marie-Agnès Jacques
- Institut Agro, INRAE, IRHS, SFR QUASAV, University of Angers, Angers F-49000, France
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
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Heiden N, Broders KA, Hutin M, Castro MO, Roman-Reyna V, Toth H, Jacobs JM. Bacterial Leaf Streak Diseases of Plants: Symptom Convergence in Monocot Plants by Distant Pathogenic Xanthomonas Species. PHYTOPATHOLOGY 2023; 113:2048-2055. [PMID: 37996392 DOI: 10.1094/phyto-05-23-0155-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
Bacterial leaf streak (BLS) is a disease of monocot plants caused by Xanthomonas translucens on small grains, X. vasicola on maize and sorghum, and X. oryzae on rice. These three pathogens cause remarkably similar symptomology in their host plants. Despite causing similar symptoms, BLS pathogens are dispersed throughout the larger Xanthomonas phylogeny. Each aforementioned species includes strain groups that do not cause BLS and instead cause vascular disease. In this commentary, we hypothesize that strains of X. translucens, X. vasicola, and X. oryzae convergently evolved to cause BLS due to shared evolutionary pressures. We examined the diversity of secreted effectors, which may be important virulence factors for BLS pathogens and their evolution. We discuss evidence that differences in gene regulation and abilities to manipulate plant hormones may also separate BLS pathogens from other Xanthomonas species or pathovars. BLS is becoming an increasing issue across the three pathosystems. Overall, we hope that a better understanding of conserved mechanisms used by BLS pathogens will enable researchers to translate findings across production systems and guide approaches to control this (re)emerging threat.
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Affiliation(s)
- Nathaniel Heiden
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Kirk A Broders
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604, U.S.A
| | - Mathilde Hutin
- Plant Health Institute of Montpellier, University of Montpellier, IRD, CIRAD, INRAE, Institut Agro, Montpellier, France
| | - Mary Ortiz Castro
- Horticulture and Extension Programs, Colorado State University, Castle Rock, CO 80106, U.S.A
| | - Verónica Roman-Reyna
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, U.S.A
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Hannah Toth
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Jonathan M Jacobs
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Diseases Institute, The Ohio State University, Columbus, OH 43210, U.S.A
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6
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Kałużna M, Prokić A, Obradović A, Weldon WA, Stockwell VO, Pothier JF. Specific and sensitive detection tools for Xanthomonas arboricola pv. corylina, the causal agent of bacterial blight of hazelnut, developed with comparative genomics. FRONTIERS IN PLANT SCIENCE 2023; 14:1254107. [PMID: 37780515 PMCID: PMC10535005 DOI: 10.3389/fpls.2023.1254107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/18/2023] [Indexed: 10/03/2023]
Abstract
Xanthomonas arboricola pv. corylina (Xac; formerly Xanthomonas campestris pv. corylina) is the causal agent of the bacterial blight of hazelnuts, a devastating disease of trees in plant nurseries and young orchards. Currently, there are no PCR assays to distinguish Xac from all other pathovars of X. arboricola. A comparative genomics approach with publicly available genomes of Xac was used to identify unique sequences, conserved across the genomes of the pathogen. We identified a 2,440 bp genomic region that was unique to Xac and designed identification and detection systems for conventional PCR, qPCR (SYBR® Green and TaqMan™), and loop-mediated isothermal amplification (LAMP). All PCR assays performed on genomic DNA isolated from eight X. arboricola pathovars and closely related bacterial species confirmed the specificity of designed primers. These new multi-platform molecular diagnostic tools may be used by plant clinics and researchers to detect and identify Xac in pure cultures and hazelnut tissues rapidly and accurately.
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Affiliation(s)
- Monika Kałużna
- The National Institute of Horticultural Research, Skierniewice, Poland
| | - Andjelka Prokić
- University of Belgrade, Faculty of Agriculture, Belgrade, Serbia
| | - Aleksa Obradović
- University of Belgrade, Faculty of Agriculture, Belgrade, Serbia
| | | | - Virginia O. Stockwell
- United States Department of Agriculture, Agricultural Research Service, Horticultural Crops Disease and Pest Management Research Unit, Corvallis, OR, United States
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research Group, Institute for Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland
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Campos PE, Pruvost O, Boyer K, Chiroleu F, Cao TT, Gaudeul M, Baider C, Utteridge TMA, Becker N, Rieux A, Gagnevin L. Herbarium specimen sequencing allows precise dating of Xanthomonas citri pv. citri diversification history. Nat Commun 2023; 14:4306. [PMID: 37474518 PMCID: PMC10359311 DOI: 10.1038/s41467-023-39950-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/15/2023] [Indexed: 07/22/2023] Open
Abstract
Herbarium collections are an important source of dated, identified and preserved DNA, whose use in comparative genomics and phylogeography can shed light on the emergence and evolutionary history of plant pathogens. Here, we reconstruct 13 historical genomes of the bacterial crop pathogen Xanthomonas citri pv. citri (Xci) from infected Citrus herbarium specimens. Following authentication based on ancient DNA damage patterns, we compare them with a large set of modern genomes to estimate their phylogenetic relationships, pathogenicity-associated gene content and several evolutionary parameters. Our results indicate that Xci originated in Southern Asia ~11,500 years ago (perhaps in relation to Neolithic climate change and the development of agriculture) and diversified during the beginning of the 13th century, after Citrus diversification and before spreading to the rest of the world (probably via human-driven expansion of citriculture through early East-West trade and colonization).
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Affiliation(s)
- Paola E Campos
- CIRAD, UMR PVBMT, F-97410, St Pierre, La Réunion, France
- Institut de Systématique, Évolution, Biodiversité (ISyEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 50, 75005, Paris, France
| | | | - Karine Boyer
- CIRAD, UMR PVBMT, F-97410, St Pierre, La Réunion, France
| | | | - Thuy Trang Cao
- CIRAD, UMR PVBMT, F-97410, St Pierre, La Réunion, France
| | - Myriam Gaudeul
- Institut de Systématique, Évolution, Biodiversité (ISyEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 50, 75005, Paris, France
- Herbier national, Muséum national d'Histoire naturelle, CP39, 57 rue Cuvier, 75005, Paris, France
| | - Cláudia Baider
- The Mauritius Herbarium, Agricultural Services, Ministry of Agro-Industry and Food Security, R.E. Vaughan Building (MSIRI Compound), Reduit, 80835, Mauritius
| | | | - Nathalie Becker
- Institut de Systématique, Évolution, Biodiversité (ISyEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 50, 75005, Paris, France
| | - Adrien Rieux
- CIRAD, UMR PVBMT, F-97410, St Pierre, La Réunion, France.
| | - Lionel Gagnevin
- PHIM Plant Health Institute, Univ. Montpellier, CIRAD, INRAE, Institut Agro, IRD, Montpellier, France.
- CIRAD, UMR PHIM, Montpellier, France.
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8
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Harrison J, Hussain RMF, Greer SF, Ntoukakis V, Aspin A, Vicente JG, Grant M, Studholme DJ. Draft genome sequences for ten strains of Xanthomonas species that have phylogenomic importance. Access Microbiol 2023; 5:acmi000532.v3. [PMID: 37601434 PMCID: PMC10436009 DOI: 10.1099/acmi.0.000532.v3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/25/2023] [Indexed: 08/22/2023] Open
Abstract
Here we report draft-quality genome sequences for pathotype strains of eight plant-pathogenic bacterial pathovars: Xanthomonas campestris pv. asclepiadis, X. campestris pv. cannae, X. campestris pv. esculenti, X. campestris pv. nigromaculans, X. campestris pv. parthenii, X. campestris pv. phormiicola, X. campestris pv. zinniae and X. dyei pv. eucalypti (= X. campestris pv. eucalypti). We also sequenced the type strain of species X. melonis and the unclassified Xanthomonas strain NCPPB 1067. These data will be useful for phylogenomic and taxonomic studies, filling some important gaps in sequence coverage of Xanthomonas phylogenetic diversity. We include representatives of previously under-sequenced pathovars and species-level clades. Furthermore, these genome sequences may be useful in elucidating the molecular basis for important phenotypes, such as biosynthesis of coronatine-related toxins and degradation of fungal toxin cercosporin.
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Affiliation(s)
| | - Rana Muhammad Fraz Hussain
- Gibbet Hill Campus, School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
- Wellesbourne Campus, School of Life Sciences, University of Warwick, Coventry, CV35 9EF, UK
| | - Shannon F. Greer
- Gibbet Hill Campus, School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
- Wellesbourne Campus, School of Life Sciences, University of Warwick, Coventry, CV35 9EF, UK
| | - Vardis Ntoukakis
- Gibbet Hill Campus, School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Andrew Aspin
- Fera Science Ltd., York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK
| | - Joana G. Vicente
- Wellesbourne Campus, School of Life Sciences, University of Warwick, Coventry, CV35 9EF, UK
- Fera Science Ltd., York Biotech Campus, Sand Hutton, York, YO41 1LZ, UK
| | - Murray Grant
- Gibbet Hill Campus, School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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Agarwal V, Stubits R, Nassrullah Z, Dillon MM. Pangenome insights into the diversification and disease specificity of worldwide Xanthomonas outbreaks. Front Microbiol 2023; 14:1213261. [PMID: 37476668 PMCID: PMC10356107 DOI: 10.3389/fmicb.2023.1213261] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/15/2023] [Indexed: 07/22/2023] Open
Abstract
The bacterial genus Xanthomonas is responsible for disease outbreaks in several hundred plant species, many of them economically important crops. In the era of next-generation sequencing, thousands of strains from this genus have now been sequenced as part of isolated studies that focus on outbreak characterization, host range, diversity, and virulence factor identification. However, these data have not been synthesized and we lack a comprehensive phylogeny for the genus, with some species designations in public databases still relying on phenotypic similarities and representative sequence typing. The extent of genetic cohesiveness among Xanthomonas strains, the distribution of virulence factors across strains, and the impact of evolutionary history on host range across the genus are also poorly understood. In this study, we present a pangenome analysis of 1,910 diverse Xanthomonas genomes, highlighting their evolutionary relationships, the distribution of virulence-associated genes across strains, and rates of horizontal gene transfer. We find a number of broadly conserved classes of virulence factors and considerable diversity in the Type 3 Secretion Systems (T3SSs) and Type 3 Secreted Effector (T3SE) repertoires of different Xanthomonas species. We also use these data to re-assign incorrectly classified strains to phylogenetically informed species designations and find evidence of both monophyletic host specificity and convergent evolution of phylogenetically distant strains to the same host. Finally, we explore the role of recombination in maintaining genetic cohesion within the Xanthomonas genus as a result of both ancestral and recent recombination events. Understanding the evolutionary history of Xanthomonas species and the relationship of key virulence factors with host-specificity provides valuable insight into the mechanisms through which Xanthomonas species shift between hosts and will enable us to develop more robust resistance strategies against these highly virulent pathogens.
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Affiliation(s)
- Viplav Agarwal
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Rachel Stubits
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Zain Nassrullah
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Marcus M. Dillon
- Department of Biology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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10
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Hamim I, Sekine KT, Komatsu K. How do emerging long-read sequencing technologies function in transforming the plant pathology research landscape? PLANT MOLECULAR BIOLOGY 2022; 110:469-484. [PMID: 35962900 DOI: 10.1007/s11103-022-01305-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Long-read sequencing technologies are revolutionizing the sequencing and analysis of plant and pathogen genomes and transcriptomes, as well as contributing to emerging areas of interest in plant-pathogen interactions, disease management techniques, and the introduction of new plant varieties or cultivars. Long-read sequencing (LRS) technologies are progressively being implemented to study plants and pathogens of agricultural importance, which have substantial economic effects. The variability and complexity of the genome and transcriptome affect plant growth, development and pathogen responses. Overcoming the limitations of second-generation sequencing, LRS technology has significantly increased the length of a single contiguous read from a few hundred to millions of base pairs. Because of the longer read lengths, new analysis methods and tools have been developed for plant and pathogen genomics and transcriptomics. LRS technologies enable faster, more efficient, and high-throughput ultralong reads, allowing direct sequencing of genomes that would be impossible or difficult to investigate using short-read sequencing approaches. These benefits include genome assembly in repetitive areas, creating more comprehensive and exact genome determinations, assembling full-length transcripts, and detecting DNA and RNA alterations. Furthermore, these technologies allow for the identification of transcriptome diversity, significant structural variation analysis, and direct epigenetic mark detection in plant and pathogen genomic regions. LRS in plant pathology is found efficient for identifying and characterization of effectors in plants as well as known and unknown plant pathogens. In this review, we investigate how these technologies are transforming the landscape of determination and characterization of plant and pathogen genomes and transcriptomes efficiently and accurately. Moreover, we highlight potential areas of interest offered by LRS technologies for future study into plant-pathogen interactions, disease control strategies, and the development of new plant varieties or cultivars.
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Affiliation(s)
- Islam Hamim
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan
- International Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
- Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Ken-Taro Sekine
- Faculty of Agriculture, University of the Ryukyus, Okinawa, Japan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan.
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11
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Luneau JS, Baudin M, Quiroz Monnens T, Carrère S, Bouchez O, Jardinaud M, Gris C, François J, Ray J, Torralba B, Arlat M, Lewis JD, Lauber E, Deutschbauer AM, Noël LD, Boulanger A. Genome-wide identification of fitness determinants in the Xanthomonas campestris bacterial pathogen during early stages of plant infection. THE NEW PHYTOLOGIST 2022; 236:235-248. [PMID: 35706385 PMCID: PMC9543026 DOI: 10.1111/nph.18313] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/07/2022] [Indexed: 05/31/2023]
Abstract
Plant diseases are an important threat to food production. While major pathogenicity determinants required for disease have been extensively studied, less is known on how pathogens thrive during host colonization, especially at early infection stages. Here, we used randomly barcoded-transposon insertion site sequencing (RB-TnSeq) to perform a genome-wide screen and identify key bacterial fitness determinants of the vascular pathogen Xanthomonas campestris pv campestris (Xcc) during infection of the cauliflower host plant (Brassica oleracea). This high-throughput analysis was conducted in hydathodes, the natural entry site of Xcc, in xylem sap and in synthetic media. Xcc did not face a strong bottleneck during hydathode infection. In total, 181 genes important for fitness were identified in plant-associated environments with functional enrichment in genes involved in metabolism but only few genes previously known to be involved in virulence. The biological relevance of 12 genes was independently confirmed by phenotyping single mutants. Notably, we show that XC_3388, a protein with no known function (DUF1631), plays a key role in the adaptation and virulence of Xcc possibly through c-di-GMP-mediated regulation. This study revealed yet unsuspected social behaviors adopted by Xcc individuals when confined inside hydathodes at early infection stages.
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Affiliation(s)
- Julien S. Luneau
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Maël Baudin
- Plant Gene Expression Center, USDAAlbanyCA94710USA
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
| | - Thomas Quiroz Monnens
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Sébastien Carrère
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Olivier Bouchez
- Genotoul Genome & Transcriptome (GeT‐PlaGe), INRAE31320Castanet‐TolosanFrance
| | | | - Carine Gris
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jonas François
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jayashree Ray
- Environmental Genomics and Systems Biology DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Babil Torralba
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Matthieu Arlat
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Jennifer D. Lewis
- Plant Gene Expression Center, USDAAlbanyCA94710USA
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
| | - Emmanuelle Lauber
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Adam M. Deutschbauer
- Department of Plant and Microbial BiologyUniversity of CaliforniaBerkeleyCA94720USA
- Environmental Genomics and Systems Biology DivisionLawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Laurent D. Noël
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
| | - Alice Boulanger
- LIPME, Université de Toulouse, INRAE, CNRSUniversité Paul Sabatier31320Castanet‐TolosanFrance
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12
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Malmstrom CM, Martin MD, Gagnevin L. Exploring the Emergence and Evolution of Plant Pathogenic Microbes Using Historical and Paleontological Sources. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:187-209. [PMID: 35483672 DOI: 10.1146/annurev-phyto-021021-041830] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Biotechnological advances now permit broad exploration of past microbial communities preserved in diverse substrates. Despite biomolecular degradation, high-throughput sequencing of preserved materials can yield invaluable genomic and metagenomic data from the past. This line of research has expanded from its initial human- and animal-centric foci to include plant-associated microbes (viruses, archaea, bacteria, fungi, and oomycetes), for which historical, archaeological, and paleontological data illuminate past epidemics and evolutionary history. Genetic mechanisms underlying the acquisition of microbial pathogenicity, including hybridization, polyploidization, and horizontal gene transfer, can now be reconstructed, as can gene-for-gene coevolution with plant hosts. Epidemiological parameters, such as geographic origin and range expansion, can also be assessed. Building on published case studies with individual phytomicrobial taxa, the stage is now set for broader, community-wide studies of preserved plant microbiomes to strengthen mechanistic understanding of microbial interactions and plant disease emergence.
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Affiliation(s)
- Carolyn M Malmstrom
- Department of Plant Biology and Program in Ecology, Evolution, and Behavior, Michigan State University, East Lansing, Michigan, USA
| | - Michael D Martin
- Department of Natural History, University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Lionel Gagnevin
- Plant Health Institute of Montpellier, CIRAD, Montpellier, France;
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13
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Zarei S, Taghavi SM, Rahimi T, Mafakheri H, Potnis N, Koebnik R, Fischer-Le Saux M, Pothier JF, Palacio Bielsa A, Cubero J, Portier P, Jacques MA, Osdaghi E. Taxonomic Refinement of Xanthomonas arboricola. PHYTOPATHOLOGY 2022; 112:1630-1639. [PMID: 35196068 DOI: 10.1094/phyto-12-21-0519-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Xanthomonas arboricola comprises a number of economically important fruit tree pathogens classified within different pathovars. Dozens of nonpathogenic and taxonomically unvalidated strains are also designated as X. arboricola, leading to a complicated taxonomic status in the species. In this study, we have evaluated the whole-genome resources of all available Xanthomonas spp. strains designated as X. arboricola in the public databases to refine the members of the species based on DNA similarity indexes and core genome-based phylogeny. Our results show that, of the nine validly described pathovars within X. arboricola, pathotype strains of seven pathovars are taxonomically genuine, belonging to the core clade of the species regardless of their pathogenicity on the host of isolation (thus the validity of pathovar status). However, strains of X. arboricola pv. guizotiae and X. arboricola pv. populi do not belong to X. arboricola because of the low DNA similarities between the type strain of the species and the pathotype strains of these two pathovars. Thus, we propose to elevate the two pathovars to the rank of a species as X. guizotiae sp. nov. with the type strain CFBP 7408T and X. populina sp. nov. with the type strain CFBP 3123T. In addition, other mislabeled strains of X. arboricola were scattered within Xanthomonas spp. that belong to previously described species or represent novel species that await formal description.
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Affiliation(s)
- Sadegh Zarei
- Department of Plant Protection, School of Agriculture, Shiraz University, Shiraz, Iran
- Department of Plant Protection, College of Agriculture, University of Tehran, Karaj, Iran
| | - S Mohsen Taghavi
- Department of Plant Protection, School of Agriculture, Shiraz University, Shiraz, Iran
| | - Touraj Rahimi
- Department of Agronomy and Plant Breeding, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
| | - Hamzeh Mafakheri
- Department of Plant Protection, School of Agriculture, Shiraz University, Shiraz, Iran
- Department of Plant Protection, College of Agriculture, University of Tehran, Karaj, Iran
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, U.S.A
| | - Ralf Koebnik
- Plant Health Institute of Montpellier, University of Montpellier, CIRAD, INRAE, Institut Agro, IRD, Montpellier, France
| | | | - Joël F Pothier
- Environmental Genomics and Systems Biology Research Group, Institute for Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland
| | - Ana Palacio Bielsa
- Departamento de Protección Vegetal, Centro de Investigación y Tecnología Agroalimentaria de Aragón, Instituto Agroalimentario de Aragón-IA2 (CITA-Universidad de Zaragoza), Zaragoza, Spain
| | - Jaime Cubero
- Departamento de Protección Vegetal, Centro Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Madrid, Spain
| | - Perrine Portier
- Institut Agro, Université de Angers, INRAE, IRHS, SFR QUASAV, CIRM-CFBP, Angers, France
| | - Marie-Agnes Jacques
- Institut Agro, Université de Angers, INRAE, IRHS, SFR QUASAV, CIRM-CFBP, Angers, France
| | - Ebrahim Osdaghi
- Department of Plant Protection, College of Agriculture, University of Tehran, Karaj, Iran
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14
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Analysis of the Diversity of Xylophilus ampelinus Strains Held in CIRM-CFBP Reveals a Strongly Homogenous Species. Microorganisms 2022; 10:microorganisms10081531. [PMID: 36013950 PMCID: PMC9412579 DOI: 10.3390/microorganisms10081531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/22/2022] [Accepted: 07/27/2022] [Indexed: 02/01/2023] Open
Abstract
Xylophilus ampelinus is the causal agent of blight and canker on grapevine. Only a few data are available on this species implying that the occurrence of this pathogen may be underestimated, and its actual ecological niche may not be understood. Moreover, its genetic diversity is not well known. To improve our knowledge of this species, an analysis of the complete genome sequences available in NCBI was performed. It appeared that several sequences are misidentified. The complete genome sequence of the type strain was obtained and primers designed in order to sequence gyrB and rpoD genes for the strains held in CIRM-CFBP. The genetic barcoding data were obtained for 93 strains, isolated over 35 years and from several geographical origins. The species revealed to be strongly homogenous, displaying nearly identical sequences for all strains. However, the oldest strains of this collection were isolated in 2001 therefore, a new isolation campaign and epidemiological surveys are necessary, along with the obtention of new complete genome sequences for this species.
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15
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Rosenthal E, Potnis N, Bull CT. Comparative Genomic Analysis of the Lettuce Bacterial Leaf Spot Pathogen, Xanthomonas hortorum pv. vitians, to Investigate Race Specificity. Front Microbiol 2022; 13:840311. [PMID: 35516433 PMCID: PMC9062649 DOI: 10.3389/fmicb.2022.840311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/09/2022] [Indexed: 01/01/2023] Open
Abstract
Bacterial leaf spot (BLS) of lettuce caused by Xanthomonas hortorum pv. vitians (Xhv) was first described over 100 years ago and remains a significant threat to lettuce cultivation today. This study investigated the genetic relatedness of the Xhv strains and the possible genetic sources of this race-specific pathogenicity. Whole genome sequences of eighteen Xhv strains representing the three races, along with eight related Xanthomonas strains, were included in the analysis. A maximum likelihood phylogeny based on concatenated whole genome SNPs confirmed previous results describing two major lineages of Xhv strains. Gene clusters encoding secretion systems, secondary metabolites, and bacteriocins were assessed to identify putative virulence factors that distinguish the Xhv races. Genome sequences were mined for effector genes, which have been shown to be involved in race specificity in other systems. Two effectors identified in this study, xopAQ and the novel variant xopAF2, were revealed as possible mediators of a gene-for-gene interaction between Xhv race 1 and 3 strains and wild lettuce Lactuca serriola ARM-09-161-10-1. Transposase sequence identified downstream of xopAF2 and prophage sequence found nearby within Xhv race 1 and 3 insertion sequences suggest that this gene may have been acquired through phage-mediated gene transfer. No other factors were identified from these analyses that distinguish the Xhv races.
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Affiliation(s)
- Emma Rosenthal
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Carolee T Bull
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, United States
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16
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Exploiting the antibacterial mechanism of phenazine substances from Lysobacter antibioticus 13-6 against Xanthomonas oryzae pv. oryzicola. J Microbiol 2022; 60:496-510. [PMID: 35362894 DOI: 10.1007/s12275-022-1542-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/24/2022] [Accepted: 01/28/2022] [Indexed: 10/18/2022]
Abstract
Bacterial leaf streak caused by Xanthomonas oryzae pv. oryzicola (Xoc) is one of the most destructive diseases affecting rice production worldwide. In this study, we extracted and purified phenazine substances from the secondary metabolites of Lysobacter antibioticus 13-6. The bacteriostatic mechanism of phenazine substances against Xoc was investigated through physiological response and transcriptomic analysis. Results showed that phenazine substances affects the cell membrane permeability of Xoc, which causes cell swelling and deformation, blockage of flagellum synthesis, and imbalance of intracellular environment. The changes in intracellular environment affect the physiological and metabolic functions of Xoc, which reduces the formation of pathogenic factors and pathogenicity. Through transcriptomic analysis, we found that among differentially expressed genes, the expression of 595 genes was induced significantly (275 up-regulated and 320 down-regulated). In addition, we observed that phenazine substances affects three main functions of Xoc, i.e., transmembrane transporter activity, DNA-mediated transposition, and structural molecular activity. Phenazine substances also inhibits the potassium ion transport system that reduces Xoc resistance and induces the phosphate ion transport system to maintain the stability of the internal environment. Finally, we conclude that phenazine substances could retard cell growth and reduce the pathogenicity of Xoc by affecting cell structure and physiological metabolism. Altogether, our study highlights latest insights into the antibacterial mechanism of phenazine substances against Xoc and provides basic guidance to manage the incidence of bacterial leaf streak of rice.
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17
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Dia NC, Morinière L, Cottyn B, Bernal E, Jacobs J, Koebnik R, Osdaghi E, Potnis N, Pothier J. Xanthomonas hortorum - beyond gardens: Current taxonomy, genomics, and virulence repertoires. MOLECULAR PLANT PATHOLOGY 2022; 23:597-621. [PMID: 35068051 PMCID: PMC8995068 DOI: 10.1111/mpp.13185] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 05/02/2023]
Abstract
TAXONOMY Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Lysobacterales (earlier synonym of Xanthomonadales); Family Lysobacteraceae (earlier synonym of Xanthomonadaceae); Genus Xanthomonas; Species X. hortorum; Pathovars: pv. carotae, pv. vitians, pv. hederae, pv. pelargonii, pv. taraxaci, pv. cynarae, and pv. gardneri. HOST RANGE Xanthomonas hortorum affects agricultural crops, and horticultural and wild plants. Tomato, carrot, artichoke, lettuce, pelargonium, ivy, and dandelion were originally described as the main natural hosts of the seven separate pathovars. Artificial inoculation experiments also revealed other hosts. The natural and experimental host ranges are expected to be broader than initially assumed. Additionally, several strains, yet to be assigned to a pathovar within X. hortorum, cause diseases on several other plant species such as peony, sweet wormwood, lavender, and oak-leaf hydrangea. EPIDEMIOLOGY AND CONTROL X. hortorum pathovars are mainly disseminated by infected seeds (e.g., X. hortorum pvs carotae and vitians) or cuttings (e.g., X. hortorum pv. pelargonii) and can be further dispersed by wind and rain, or mechanically transferred during planting and cultivation. Global trade of plants, seeds, and other propagating material constitutes a major pathway for their introduction and spread into new geographical areas. The propagules of some pathovars (e.g., X. horturum pv. pelargonii) are spread by insect vectors, while those of others can survive in crop residues and soils, and overwinter until the following growing season (e.g., X. hortorum pvs vitians and carotae). Control measures against X. hortorum pathovars are varied and include exclusion strategies (i.e., by using certification programmes and quarantine regulations) to multiple agricultural practices such as the application of phytosanitary products. Copper-based compounds against X. hortorum are used, but the emergence of copper-tolerant strains represents a major threat for their effective management. With the current lack of efficient chemical or biological disease management strategies, host resistance appears promising, but is not without challenges. The intrastrain genetic variability within the same pathovar poses a challenge for breeding cultivars with durable resistance. USEFUL WEBSITES https://gd.eppo.int/taxon/XANTGA, https://gd.eppo.int/taxon/XANTCR, https://gd.eppo.int/taxon/XANTPE, https://www.euroxanth.eu, http://www.xanthomonas.org, http://www.xanthomonas.org/dokuwiki.
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Affiliation(s)
- Nay C. Dia
- Environmental Genomics and Systems Biology Research GroupInstitute for Natural Resource SciencesZurich University of Applied SciencesWädenswilSwitzerland
- Molecular Plant BreedingInstitute of Agricultural SciencesETH ZurichZurichSwitzerland
| | - Lucas Morinière
- University of LyonUniversité Claude Bernard Lyon 1CNRSINRAEUMR Ecologie MicrobienneVilleurbanneFrance
| | - Bart Cottyn
- Plant Sciences UnitFlanders Research Institute for Agriculture, Fisheries and FoodMerelbekeBelgium
| | - Eduardo Bernal
- Department of Plant PathologyThe Ohio State UniversityColumbusOhioUSA
| | - Jonathan M. Jacobs
- Department of Plant PathologyThe Ohio State UniversityColumbusOhioUSA
- Infectious Diseases InstituteThe Ohio State UniversityColumbusOhioUSA
| | - Ralf Koebnik
- Plant Health Institute of MontpellierUniversity of Montpellier, CIRAD, INRAe, Institut Agro, IRDMontpellierFrance
| | - Ebrahim Osdaghi
- Department of Plant ProtectionCollege of AgricultureUniversity of TehranKarajIran
| | - Neha Potnis
- Department of Entomology and Plant PathologyAuburn UniversityAlabamaUSA
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research GroupInstitute for Natural Resource SciencesZurich University of Applied SciencesWädenswilSwitzerland
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18
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Liyanapathiranage P, Wagner N, Avram O, Pupko T, Potnis N. Phylogenetic Distribution and Evolution of Type VI Secretion System in the Genus Xanthomonas. Front Microbiol 2022; 13:840308. [PMID: 35495725 PMCID: PMC9048695 DOI: 10.3389/fmicb.2022.840308] [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: 12/21/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
The type VI secretion system (T6SS) present in many Gram-negative bacteria is a contact-dependent apparatus that can directly deliver secreted effectors or toxins into diverse neighboring cellular targets including both prokaryotic and eukaryotic organisms. Recent reverse genetics studies with T6 core gene loci have indicated the importance of functional T6SS toward overall competitive fitness in various pathogenic Xanthomonas spp. To understand the contribution of T6SS toward ecology and evolution of Xanthomonas spp., we explored the distribution of the three distinguishable T6SS clusters, i3*, i3***, and i4, in approximately 1,740 Xanthomonas genomes, along with their conservation, genetic organization, and their evolutionary patterns in this genus. Screening genomes for core genes of each T6 cluster indicated that 40% of the sequenced strains possess two T6 clusters, with combinations of i3*** and i3* or i3*** and i4. A few strains of Xanthomonas citri, Xanthomonas phaseoli, and Xanthomonas cissicola were the exception, possessing a unique combination of i3* and i4. The findings also indicated clade-specific distribution of T6SS clusters. Phylogenetic analysis demonstrated that T6SS clusters i3* and i3*** were probably acquired by the ancestor of the genus Xanthomonas, followed by gain or loss of individual clusters upon diversification into subsequent clades. T6 i4 cluster has been acquired in recent independent events by group 2 xanthomonads followed by its spread via horizontal dissemination across distinct clades across groups 1 and 2 xanthomonads. We also noted reshuffling of the entire core T6 loci, as well as T6SS spike complex components, hcp and vgrG, among different species. Our findings indicate that gain or loss events of specific T6SS clusters across Xanthomonas phylogeny have not been random.
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Affiliation(s)
| | - Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Oren Avram
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
- *Correspondence: Neha Potnis,
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19
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Ramnarine SDBJ, Jayaraman J, Ramsubhag A. Comparative genomics of the black rot pathogen Xanthomonas campestris pv. campestris and non-pathogenic co-inhabitant Xanthomonas melonis from Trinidad reveal unique pathogenicity determinants and secretion system profiles. PeerJ 2022; 9:e12632. [PMID: 35036136 PMCID: PMC8734464 DOI: 10.7717/peerj.12632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 11/22/2021] [Indexed: 11/20/2022] Open
Abstract
Black-rot disease caused by the phytopathogen Xanthomonas campestris pv. campestris (Xcc) continues to have considerable impacts on the productivity of cruciferous crops in Trinidad and Tobago and the wider Caribbean region. While the widespread occurrence of resistance of Xcc against bactericidal agrochemicals can contribute to the high disease burdens, the role of virulence and pathogenicity features of local strains on disease prevalence and severity has not been investigated yet. In the present study, a comparative genomic analysis was performed on 6 pathogenic Xcc and 4 co-isolated non-pathogenic Xanthomonas melonis (Xmel) strains from diseased crucifer plants grown in fields with heavy chemical use in Trinidad. Native isolates were grouped into two known and four newly assigned ribosomal sequence types (rST). Mobile genetic elements were identified which belonged to the IS3, IS5 family, Tn3 transposon, resolvases, and tra T4SS gene clusters. Additionally, exogenous plasmid derived sequences with origins from other bacterial species were characterised. Although several instances of genomic rearrangements were observed, native Xcc and Xmel isolates shared a significant level of structural homology with reference genomes, Xcc ATCC 33913 and Xmel CFBP4644, respectively. Complete T1SS hlyDB, T2SS, T4SS vir and T5SS xadA, yapH and estA gene clusters were identified in both species. Only Xmel strains contained a complete T6SS but no T3SS. Both species contained a complex repertoire of extracellular cell wall degrading enzymes. Native Xcc strains contained 37 T3SS and effector genes but a variable and unique profile of 8 avr, 4 xop and 1 hpa genes. Interestingly, Xmel strains contained several T3SS effectors with low similarity to references including avrXccA1 (~89%), hrpG (~73%), hrpX (~90%) and xopAZ (~87%). Furthermore, only Xmel genomes contained a CRISPR-Cas I-F array, but no lipopolysaccharide wxc gene cluster. Xmel strains were confirmed to be non-pathogenic by pathogenicity assays. The results of this study will be useful to guide future research into virulence mechanisms, agrochemical resistance, pathogenomics and the potential role of the co-isolated non-pathogenic Xanthomonas strains on Xcc infections.
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Affiliation(s)
- Stephen D B Jr Ramnarine
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Jayaraj Jayaraman
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Adesh Ramsubhag
- Department of Life Sciences, The University of the West Indies, St. Augustine, Trinidad and Tobago
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20
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Kałużna M, Fischer‐Le Saux M, Pothier JF, Jacques M, Obradović A, Tavares F, Stefani E. Xanthomonas arboricola pv. juglandis and pv. corylina: Brothers or distant relatives? Genetic clues, epidemiology, and insights for disease management. MOLECULAR PLANT PATHOLOGY 2021; 22:1481-1499. [PMID: 34156749 PMCID: PMC8578823 DOI: 10.1111/mpp.13073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/06/2021] [Accepted: 04/23/2021] [Indexed: 05/31/2023]
Abstract
BACKGROUND The species Xanthomonas arboricola comprises up to nine pathovars, two of which affect nut crops: pv. juglandis, the causal agent of walnut bacterial blight, brown apical necrosis, and the vertical oozing canker of Persian (English) walnut; and pv. corylina, the causal agent of the bacterial blight of hazelnut. Both pathovars share a complex population structure, represented by different clusters and several clades. Here we describe our current understanding of symptomatology, population dynamics, epidemiology, and disease control. TAXONOMIC STATUS Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Lysobacterales (earlier synonym of Xanthomonadales); Family Lysobacteraceae (earlier synonym of Xanthomonadaceae); Genus Xanthomonas; Species X. arboricola; Pathovars: pv. juglandis and pv. corylina. HOST RANGE AND SYMPTOMS The host range of each pathovar is not limited to a single species, but each infects mainly one plant species: Juglans regia (X. arboricola pv. juglandis) and Corylus avellana (X. arboricola. pv. corylina). Walnut bacterial blight is characterized by lesions on leaves and fruits, and cankers on twigs, branches, and trunks; brown apical necrosis symptoms consist of apical necrosis originating at the stigmatic end of the fruit. A peculiar symptom, the vertical oozing canker developing along the trunk, is elicited by a particular genetic lineage of the bacterium. Symptoms of hazelnut bacterial blight are visible on leaves and fruits as necrotic lesions, and on woody parts as cankers. A remarkable difference is that affected walnuts drop abundantly, whereas hazelnuts with symptoms do not. DISTRIBUTION Bacterial blight of walnut has a worldwide distribution, wherever Persian (English) walnut is cultivated; the bacterial blight of hazelnut has a more limited distribution, although disease outbreaks are currently more frequently reported. X. arboricola pv. juglandis is regulated almost nowhere, whereas X. arboricola pv. corylina is regulated in most European and Mediterranean Plant Protection Organization (EPPO) countries. EPIDEMIOLOGY AND CONTROL For both pathogens infected nursery material is the main pathway for their introduction and spread into newly cultivated areas; additionally, infected nursery material is the source of primary inoculum. X. arboricola pv. juglandis is also disseminated through pollen. Disease control is achieved through the phytosanitary certification of nursery material (hazelnut), although approved certification schemes are not currently available. Once the disease is present in walnut/hazelnut groves, copper compounds are widely used, mostly in association with dithiocarbamates; where allowed, antibiotics (preferably kasugamycin) are sprayed. The emergence of strains highly resistant to copper currently represents the major threat for effective management of the bacterial blight of walnut. USEFUL WEBSITES: https://gd.eppo.int/taxon/XANTJU, https://gd.eppo.int/taxon/XANTCY, https://www.euroxanth.eu, http://www.xanthomonas.org.
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Affiliation(s)
- Monika Kałużna
- The National Institute of Horticultural ResearchSkierniewicePoland
| | | | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research GroupInstitute for Natural Resource SciencesZurich University of Applied SciencesWädenswilSwitzerland
| | | | | | - Fernando Tavares
- Centro de Investigação em Biodiversidade e Recursos GenéticosLaboratório Associado (CIBIO‐InBIO)Universidade do PortoPortugal
- Faculdade de CiênciasDepartamento de BiologiaUniversidade do PortoPortoPortugal
| | - Emilio Stefani
- Department of Life SciencesUniversity of Modena and Reggio EmiliaReggio EmiliaItaly
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21
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Chepsergon J, Motaung TE, Moleleki LN. "Core" RxLR effectors in phytopathogenic oomycetes: A promising way to breeding for durable resistance in plants? Virulence 2021; 12:1921-1935. [PMID: 34304703 PMCID: PMC8516161 DOI: 10.1080/21505594.2021.1948277] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
Phytopathogenic oomycetes are known to successfully infect their hosts due to their ability to secrete effector proteins. Of interest to many researchers are effectors with the N-terminal RxLR motif (Arginine-any amino acid-Leucine-Arginine). Owing to advances in genome sequencing, we can now comprehend the high level of diversity among oomycete effectors, and similarly, their conservation within and among species referred to here as "core" RxLR effectors (CREs). Currently, there is a considerable number of CREs that have been identified in oomycetes. Functional characterization of these CREs propose their virulence role with the potential of targeting central cellular processes that are conserved across diverse plant species. We reason that effectors that are highly conserved and recognized by the host, could be harnessed in engineering plants for durable as well as broad-spectrum resistance.
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Affiliation(s)
- Jane Chepsergon
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Thabiso E. Motaung
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Lucy Novungayo Moleleki
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
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22
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Te Molder D, Poncheewin W, Schaap PJ, Koehorst JJ. Machine learning approaches to predict the Plant-associated phenotype of Xanthomonas strains. BMC Genomics 2021; 22:848. [PMID: 34814827 PMCID: PMC8612006 DOI: 10.1186/s12864-021-08093-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 10/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The genus Xanthomonas has long been considered to consist predominantly of plant pathogens, but over the last decade there has been an increasing number of reports on non-pathogenic and endophytic members. As Xanthomonas species are prevalent pathogens on a wide variety of important crops around the world, there is a need to distinguish between these plant-associated phenotypes. To date a large number of Xanthomonas genomes have been sequenced, which enables the application of machine learning (ML) approaches on the genome content to predict this phenotype. Until now such approaches to the pathogenomics of Xanthomonas strains have been hampered by the fragmentation of information regarding pathogenicity of individual strains over many studies. Unification of this information into a single resource was therefore considered to be an essential step. RESULTS Mining of 39 papers considering both plant-associated phenotypes, allowed for a phenotypic classification of 578 Xanthomonas strains. For 65 plant-pathogenic and 53 non-pathogenic strains the corresponding genomes were available and de novo annotated for the presence of Pfam protein domains used as features to train and compare three ML classification algorithms; CART, Lasso and Random Forest. CONCLUSION The literature resource in combination with recursive feature extraction used in the ML classification algorithms provided further insights into the virulence enabling factors, but also highlighted domains linked to traits not present in pathogenic strains.
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Affiliation(s)
- Dennie Te Molder
- Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands
| | - Wasin Poncheewin
- Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands
- UNLOCK, Wageningen University, Wageningen, the Netherlands
| | - Jasper J Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University, Wageningen, the Netherlands.
- UNLOCK, Wageningen University, Wageningen, the Netherlands.
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23
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Hotinger JA, Morris ST, May AE. The Case against Antibiotics and for Anti-Virulence Therapeutics. Microorganisms 2021; 9:2049. [PMID: 34683370 PMCID: PMC8537500 DOI: 10.3390/microorganisms9102049] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/14/2022] Open
Abstract
Although antibiotics have been indispensable in the advancement of modern medicine, there are downsides to their use. Growing resistance to broad-spectrum antibiotics is leading to an epidemic of infections untreatable by first-line therapies. Resistance is exacerbated by antibiotics used as growth factors in livestock, over-prescribing by doctors, and poor treatment adherence by patients. This generates populations of resistant bacteria that can then spread resistance genes horizontally to other bacterial species, including commensals. Furthermore, even when antibiotics are used appropriately, they harm commensal bacteria leading to increased secondary infection risk. Effective antibiotic treatment can induce bacterial survival tactics, such as toxin release and increasing resistance gene transfer. These problems highlight the need for new approaches to treating bacterial infection. Current solutions include combination therapies, narrow-spectrum therapeutics, and antibiotic stewardship programs. These mediate the issues but do not address their root cause. One emerging solution to these problems is anti-virulence treatment: preventing bacterial pathogenesis instead of using bactericidal agents. In this review, we discuss select examples of potential anti-virulence targets and strategies that could be developed into bacterial infection treatments: the bacterial type III secretion system, quorum sensing, and liposomes.
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Affiliation(s)
| | | | - Aaron E. May
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA; (J.A.H.); (S.T.M.)
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24
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Rai R, Pasion J, Majumdar T, Green CE, Hind SR. Genome Sequencing and Functional Characterization of Xanthomonas cucurbitae, the Causal Agent of Bacterial Spot Disease of Cucurbits. PHYTOPATHOLOGY 2021; 111:1289-1300. [PMID: 33734871 DOI: 10.1094/phyto-06-20-0228-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Bacterial leaf spot disease caused by Xanthomonas cucurbitae has severely affected the pumpkin industries in the Midwestern region of United States, with the bacteria mainly infecting pumpkin leaves and fruits, and leading to significant yield losses. In this study, we utilized genomics and genetics approaches to elucidate X. cucurbitae molecular mechanisms of pathogenesis during interaction with its host. We generated the first reference-quality whole-genome sequence of the X. cucurbitae type isolate and compared with other Xanthomonas species, X. cucurbitae has a smaller genome size with fewer virulence-related genes. RNA-seq analysis of X. cucurbitae under plant-mimicking media conditions showed altered transcriptional responses, with upregulation of virulence genes and downregulation of cellular homeostasis genes. Additionally, characterization of key virulence genes using gene deletion methods revealed that both type II enzymes and type III effectors are necessary for X. cucurbitae to cause infection in the pumpkin host.
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Affiliation(s)
- Rikky Rai
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
| | - Julius Pasion
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
| | - Tanvi Majumdar
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
| | - Cory E Green
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
| | - Sarah R Hind
- Department of Crop Sciences, University of Illinois, Urbana, IL 61801
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25
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Gupta PK, Balyan HS, Gautam T. SWEET genes and TAL effectors for disease resistance in plants: Present status and future prospects. MOLECULAR PLANT PATHOLOGY 2021; 22:1014-1026. [PMID: 34076324 PMCID: PMC8295518 DOI: 10.1111/mpp.13075] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/13/2021] [Accepted: 04/28/2021] [Indexed: 06/12/2023]
Abstract
SWEET genes encode sugar transporter proteins and often function as susceptibility (S) genes. Consequently, the recessive alleles of these SWEET genes provide resistance. This review summarizes the available literature on the molecular basis of the role of SWEET genes (as S genes) in the host and corresponding transcription activator-like effectors (TALEs) secreted by the pathogen. The review has four major sections, which follow a brief introduction: The first part gives some details about the occurrence and evolution of SWEET genes in approximately 30 plant species; the second part gives some details about systems where (a) SWEET genes with and without TALEs and (b) TALEs without SWEET genes cause different diseases; the third part summarizes the available information about TALEs along with interfering/truncated TALEs secreted by the pathogens; this section also summarizes the available information on effector-binding elements (EBEs) available in the promoters of either the SWEET genes or the Executor R genes; the code that is used for binding of TALEs to EBEs is also described in this section; the fourth part gives some details about the available approaches that are being used or can be used in the future for exploiting SWEET genes for developing disease-resistant cultivars. The review concludes with a section giving conclusions and future possibilities of using SWEET genes for developing disease-resistant cultivars using different approaches, including conventional breeding and genome editing.
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Affiliation(s)
| | | | - Tinku Gautam
- Department of Genetics and Plant BreedingCCS UniversityMeerutIndia
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26
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Catara V, Cubero J, Pothier JF, Bosis E, Bragard C, Đermić E, Holeva MC, Jacques MA, Petter F, Pruvost O, Robène I, Studholme DJ, Tavares F, Vicente JG, Koebnik R, Costa J. Trends in Molecular Diagnosis and Diversity Studies for Phytosanitary Regulated Xanthomonas. Microorganisms 2021; 9:862. [PMID: 33923763 PMCID: PMC8073235 DOI: 10.3390/microorganisms9040862] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/10/2021] [Accepted: 04/12/2021] [Indexed: 11/17/2022] Open
Abstract
Bacteria in the genus Xanthomonas infect a wide range of crops and wild plants, with most species responsible for plant diseases that have a global economic and environmental impact on the seed, plant, and food trade. Infections by Xanthomonas spp. cause a wide variety of non-specific symptoms, making their identification difficult. The coexistence of phylogenetically close strains, but drastically different in their phenotype, poses an added challenge to diagnosis. Data on future climate change scenarios predict an increase in the severity of epidemics and a geographical expansion of pathogens, increasing pressure on plant health services. In this context, the effectiveness of integrated disease management strategies strongly depends on the availability of rapid, sensitive, and specific diagnostic methods. The accumulation of genomic information in recent years has facilitated the identification of new DNA markers, a cornerstone for the development of more sensitive and specific methods. Nevertheless, the challenges that the taxonomic complexity of this genus represents in terms of diagnosis together with the fact that within the same bacterial species, groups of strains may interact with distinct host species demonstrate that there is still a long way to go. In this review, we describe and discuss the current molecular-based methods for the diagnosis and detection of regulated Xanthomonas, taxonomic and diversity studies in Xanthomonas and genomic approaches for molecular diagnosis.
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Affiliation(s)
- Vittoria Catara
- Department of Agriculture, Food and Environment, University of Catania, 95125 Catania, Italy
| | - Jaime Cubero
- National Institute for Agricultural and Food Research and Technology (INIA), 28002 Madrid, Spain;
| | - Joël F. Pothier
- Environmental Genomics and Systems Biology Research Group, Institute for Natural Resource Sciences, Zurich University of Applied Sciences (ZHAW), 8820 Wädenswil, Switzerland;
| | - Eran Bosis
- Department of Biotechnology Engineering, ORT Braude College of Engineering, Karmiel 2161002, Israel;
| | - Claude Bragard
- UCLouvain, Earth & Life Institute, Applied Microbiology, 1348 Louvain-la-Neuve, Belgium;
| | - Edyta Đermić
- Department of Plant Pathology, Faculty of Agriculture, University of Zagreb, 10000 Zagreb, Croatia;
| | - Maria C. Holeva
- Benaki Phytopathological Institute, Scientific Directorate of Phytopathology, Laboratory of Bacteriology, GR-14561 Kifissia, Greece;
| | - Marie-Agnès Jacques
- IRHS, INRA, AGROCAMPUS-Ouest, Univ Angers, SFR 4207 QUASAV, 49071 Beaucouzé, France;
| | - Francoise Petter
- European and Mediterranean Plant Protection Organization (EPPO/OEPP), 75011 Paris, France;
| | - Olivier Pruvost
- CIRAD, UMR PVBMT, F-97410 Saint Pierre, La Réunion, France; (O.P.); (I.R.)
| | - Isabelle Robène
- CIRAD, UMR PVBMT, F-97410 Saint Pierre, La Réunion, France; (O.P.); (I.R.)
| | | | - Fernando Tavares
- CIBIO—Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO-Laboratório Associado, Universidade do Porto, 4485-661 Vairão, Portugal; or
- FCUP-Faculdade de Ciências, Departamento de Biologia, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | | | - Ralf Koebnik
- Plant Health Institute of Montpellier (PHIM), Univ Montpellier, Cirad, INRAe, Institut Agro, IRD, 34398 Montpellier, France;
| | - Joana Costa
- Centre for Functional Ecology-Science for People & the Planet, Department of Life Sciences, University of Coimbra, 300-456 Coimbra, Portugal
- Laboratory for Phytopathology, Instituto Pedro Nunes, 3030-199 Coimbra, Portugal
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27
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Koebnik R, Burokiene D, Bragard C, Chang C, Saux MFL, Kölliker R, Lang JM, Leach JE, Luna EK, Portier P, Sagia A, Ziegle J, Cohen SP, Jacobs JM. The Complete Genome Sequence of Xanthomonas theicola, the Causal Agent of Canker on Tea Plants, Reveals Novel Secretion Systems in Clade-1 Xanthomonads. PHYTOPATHOLOGY 2021; 111:611-616. [PMID: 32997607 DOI: 10.1094/phyto-07-20-0273-sc] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Xanthomonas theicola is the causal agent of bacterial canker on tea plants. There is no complete genome sequence available for X. theicola, a close relative of the species X. translucens and X. hyacinthi, thus limiting basic research for this group of pathogens. Here, we release a high-quality complete genome sequence for the X. theicola type strain, CFBP 4691T. Single-molecule real-time sequencing with a mean coverage of 264× revealed two contigs of 4,744,641 bp (chromosome) and 40,955 bp (plasmid) in size. Genome mining revealed the presence of nonribosomal peptide synthases, two CRISPR systems, the Xps type 2 secretion system, and the Hrp type 3 secretion system. Surprisingly, this strain encodes an additional type 2 secretion system and a novel type 3 secretion system with enigmatic function, hitherto undescribed for xanthomonads. Four type 3 effector genes were found on complete or partial transposons, suggesting a role of transposons in effector gene evolution and spread. This genome sequence fills an important gap to better understand the biology and evolution of the early-branching xanthomonads, also known as clade-1 xanthomonads.
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Affiliation(s)
- Ralf Koebnik
- IRD, Cirad, Université Montpellier, IPME, Montpellier, France
| | - Daiva Burokiene
- Nature Research Centre, Institute of Botany, Laboratory of Plant Pathology, Akademijos g. 2, Vilnius, Lithuania
| | - Claude Bragard
- Earth & Life Institute, Université Catholique Louvain-la-Neuve, Louvain-la-Neuve, Belgium
| | | | - Marion Fischer-Le Saux
- IRHS-UMR 1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, 49071, CIRM-CFBP, Beaucouzé, France
| | - Roland Kölliker
- Molecular Plant Breeding, Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Jillian M Lang
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Jan E Leach
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Emily K Luna
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Perrine Portier
- IRHS-UMR 1345, Université d'Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, 49071, CIRM-CFBP, Beaucouzé, France
| | - Angeliki Sagia
- IRD, Cirad, Université Montpellier, IPME, Montpellier, France
- Department of Biology, University of Crete, Heraklion, Greece
| | - Janet Ziegle
- Pacific Biosciences, Menlo Park, CA 94025, U.S.A
| | - Stephen P Cohen
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Jonathan M Jacobs
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Disease Institute, The Ohio State University, Columbus, OH 43210, U.S.A
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28
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The HrpG/HrpX Regulon of Xanthomonads-An Insight to the Complexity of Regulation of Virulence Traits in Phytopathogenic Bacteria. Microorganisms 2021; 9:microorganisms9010187. [PMID: 33467109 PMCID: PMC7831014 DOI: 10.3390/microorganisms9010187] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 12/05/2022] Open
Abstract
Bacteria of the genus Xanthomonas cause a wide variety of economically important diseases in most crops. The virulence of the majority of Xanthomonas spp. is dependent on secretion and translocation of effectors by the type 3 secretion system (T3SS) that is controlled by two master transcriptional regulators HrpG and HrpX. Since their discovery in the 1990s, the two regulators were the focal point of many studies aiming to decipher the regulatory network that controls pathogenicity in Xanthomonas bacteria. HrpG controls the expression of HrpX, which subsequently controls the expression of T3SS apparatus genes and effectors. The HrpG/HrpX regulon is activated in planta and subjected to tight metabolic and genetic regulation. In this review, we cover the advances made in understanding the regulatory networks that control and are controlled by the HrpG/HrpX regulon and their conservation between different Xanthomonas spp.
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29
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Secrete or perish: The role of secretion systems in Xanthomonas biology. Comput Struct Biotechnol J 2020; 19:279-302. [PMID: 33425257 PMCID: PMC7777525 DOI: 10.1016/j.csbj.2020.12.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/13/2020] [Accepted: 12/13/2020] [Indexed: 12/22/2022] Open
Abstract
Bacteria of the Xanthomonas genus are mainly phytopathogens of a large variety of crops of economic importance worldwide. Xanthomonas spp. rely on an arsenal of protein effectors, toxins and adhesins to adapt to the environment, compete with other microorganisms and colonize plant hosts, often causing disease. These protein effectors are mainly delivered to their targets by the action of bacterial secretion systems, dedicated multiprotein complexes that translocate proteins to the extracellular environment or directly into eukaryotic and prokaryotic cells. Type I to type VI secretion systems have been identified in Xanthomonas genomes. Recent studies have unravelled the diverse roles played by the distinct types of secretion systems in adaptation and virulence in xanthomonads, unveiling new aspects of their biology. In addition, genome sequence information from a wide range of Xanthomonas species and pathovars have become available recently, uncovering a heterogeneous distribution of the distinct families of secretion systems within the genus. In this review, we describe the architecture and mode of action of bacterial type I to type VI secretion systems and the distribution and functions associated with these important nanoweapons within the Xanthomonas genus.
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30
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Huang Y, Li T, Xu T, Tang Z, Guo J, Cai Y. Multiple Xanthomonas campestris pv. campestris 8004 type III effectors inhibit immunity induced by flg22. PLANTA 2020; 252:88. [PMID: 33057902 DOI: 10.1007/s00425-020-03484-1] [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] [Received: 12/17/2019] [Accepted: 09/30/2020] [Indexed: 06/11/2023]
Abstract
Xanthomonas campestris pv. campestris 8004 secretes several effector proteins that interfere with plant phosphorylation. Xanthomonas campestris pv. campestris (Xcc) can infect cruciferous plants and cause black rot. The strain Xcc8004 secretes effector proteins that interfere with plant cellular processes into host cells using a type III secretion (T3S) system. Several of the 24 predicted T3S effectors in the Xcc8004 genome have been implicated in the suppression of the Arabidopsis thaliana pattern-triggered immunity (PTI) response. We used an A. thaliana mesophyll protoplast-based assay to identify Xcc8004 T3S effectors that effectively interfere with PTI signalling induced by the bacterial peptide flg22. 11 of the 24 tested effector proteins (XopK, XopQ, HrpW, XopN, XopAC, XopD, XopZ1, XopAG, AvrBs2, XopL and XopX-1) inhibited expression of the flg22-inducible gene FRK1, and five effectors (XopK, XopG, XopQ, XopL and XopX-1) inhibited the expression of the flg22-inducible gene WRKY33. Therefore, there are 12 effector proteins that can inhibit the expression of relevant flg22-inducible genes. It was further investigated whether the 12 effector proteins affect the phosphorylation activation of mitogen-activated protein (MAP) kinases MPK3/MPK6, and four effector proteins (XopK, XopQ, XopZ1 and XopX-1) were found to markedly inhibit MPK3/MPK6 activation. Moreover, a subcellular localisation analysis revealed that the tested effectors were localised within various subcellular compartments. These results indicate that multiple T3S effectors in the Xcc8004 genome interfere with flg22-induced PTI signalling via various molecular mechanisms.
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Affiliation(s)
- Yan Huang
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Tongqi Li
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Ting Xu
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Zizhong Tang
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Jingya Guo
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China
| | - Yi Cai
- School of Life Sciences, Sichuan Agricultural University, Ya'an, 625014, China.
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31
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An SQ, Potnis N, Dow M, Vorhölter FJ, He YQ, Becker A, Teper D, Li Y, Wang N, Bleris L, Tang JL. Mechanistic insights into host adaptation, virulence and epidemiology of the phytopathogen Xanthomonas. FEMS Microbiol Rev 2020; 44:1-32. [PMID: 31578554 PMCID: PMC8042644 DOI: 10.1093/femsre/fuz024] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 09/29/2019] [Indexed: 01/15/2023] Open
Abstract
Xanthomonas is a well-studied genus of bacterial plant pathogens whose members cause a variety of diseases in economically important crops worldwide. Genomic and functional studies of these phytopathogens have provided significant understanding of microbial-host interactions, bacterial virulence and host adaptation mechanisms including microbial ecology and epidemiology. In addition, several strains of Xanthomonas are important as producers of the extracellular polysaccharide, xanthan, used in the food and pharmaceutical industries. This polymer has also been implicated in several phases of the bacterial disease cycle. In this review, we summarise the current knowledge on the infection strategies and regulatory networks controlling virulence and adaptation mechanisms from Xanthomonas species and discuss the novel opportunities that this body of work has provided for disease control and plant health.
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Affiliation(s)
- Shi-Qi An
- National Biofilms Innovation Centre (NBIC), Biological Sciences, University of Southampton, University Road, Southampton SO17 1BJ, UK
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Rouse Life Science Building, Auburn University, Auburn AL36849, USA
| | - Max Dow
- School of Microbiology, Food Science & Technology Building, University College Cork, Cork T12 K8AF, Ireland
| | | | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, China
| | - Anke Becker
- Loewe Center for Synthetic Microbiology and Department of Biology, Philipps-Universität Marburg, Hans-Meerwein-Straße 6, Marburg 35032, Germany
| | - Doron Teper
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred 33850, USA
| | - Yi Li
- Bioengineering Department, University of Texas at Dallas, 2851 Rutford Ave, Richardson, TX 75080, USA.,Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred 33850, USA
| | - Leonidas Bleris
- Bioengineering Department, University of Texas at Dallas, 2851 Rutford Ave, Richardson, TX 75080, USA.,Center for Systems Biology, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX 75080, USA.,Department of Biological Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, TX75080, USA
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, 100 Daxue Road, Nanning 530004, Guangxi, China
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32
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Kyrova EI, Dzhalilov FS, Ignatov AN. The role of epiphytic populations in pathogenesis of the genus Xanthomonas bacteria. BIO WEB OF CONFERENCES 2020. [DOI: 10.1051/bioconf/20202303010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Global climate warming and involvement of new regions with endemic populations of microorganisms in commercial seed production have led to an increase in the diversity of phytopathogenic bacteria that are affecting major crops, including the fruit trees. As a rule, emergence of new pathogens is associated with importation of infected seeds and planting material, cultivation of new species and varieties of plants, and expansion of agricultural trade with foreign countries. One of the leaders in diversity among phytopathogens is the genus Xanthomonas bacteria, affecting more than 400 plant species. Among the characteristic signs of xanthomonads is the high frequency of horizontal gene transfer both within the genus and between phylogenetically removed bacterial taxa – up to 25% of the genes are of this origin. In this paper, we consider another source of increasing the number of phytopathogenic species – by the epiphytic populations. These bacteria are the likely ancestral form of the phytopathogenic bacteria of the genus Xanthomonas.
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33
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Morinière L, Burlet A, Rosenthal ER, Nesme X, Portier P, Bull CT, Lavire C, Fischer-Le Saux M, Bertolla F. Clarifying the taxonomy of the causal agent of bacterial leaf spot of lettuce through a polyphasic approach reveals that Xanthomonas cynarae Trébaol et al. 2000 emend. Timilsina et al. 2019 is a later heterotypic synonym of Xanthomonas hortorum Vauterin et al. 1995. Syst Appl Microbiol 2020; 43:126087. [PMID: 32690196 DOI: 10.1016/j.syapm.2020.126087] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/21/2020] [Accepted: 04/22/2020] [Indexed: 10/24/2022]
Abstract
Assessment of the taxonomy and diversity of Xanthomonas strains causing bacterial leaf spot of lettuce (BLSL), commonly referred to as Xanthomonas campestris pv. vitians, has been a long-lasting issue which held back the global efforts made to understand this pathogen. In order to provide a sound basis essential to its study, we conducted a polyphasic approach on strains obtained through sampling campaigns or acquired from collections. Results of a multilocus sequence analysis crossed with phenotypic assays revealed that the pathotype strain does not match the description of the nomenspecies provided by Brown in 1918. However, strain LMG 938=CFBP 8686 does fit this description. Therefore, we propose that it replaces LMG 937=CFBP 2538 as pathotype strain of X. campestris pv. vitians. Then, whole-genome based phylogenies and overall genome relatedness indices calculated on taxonomically relevant strains exhibited the intermediate position of X. campestris pv. vitians between closely related species Xanthomonas hortorum and Xanthomonas cynarae. Phenotypic profiles characterized using Biolog microplates did not reveal stable diagnostic traits legitimizing their distinction. Therefore, we propose that X. cynarae Trébaol et al. 2000 emend. Timilsina et al. 2019 is a later heterotypic synonym of X. hortorum, to reclassify X. campestris pv. vitians as X. hortorum pv. vitians comb. nov. and to transfer X. cynarae pathovars in X. hortorum as X. hortorum pv. cynarae comb. nov. and X. hortorum pv. gardneri comb. nov. An emended description of X. hortorum is provided, making this extended species a promising model for the study of Xanthomonas quick adaptation to different hosts.
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Affiliation(s)
- Lucas Morinière
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
| | - Alexandre Burlet
- Station d'Expérimentation Rhône-Alpes Information Légumes, SERAIL, 69126 Brindas, France
| | - Emma R Rosenthal
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA, USA
| | - Xavier Nesme
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
| | - Perrine Portier
- IRHS, INRAE, Agrocampus-Ouest, Université d'Angers, SFR 4207 QUASAV, 49071 Beaucouzé, France
| | - Carolee T Bull
- Department of Plant Pathology and Environmental Microbiology, The Pennsylvania State University, University Park, PA, USA
| | - Céline Lavire
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
| | - Marion Fischer-Le Saux
- IRHS, INRAE, Agrocampus-Ouest, Université d'Angers, SFR 4207 QUASAV, 49071 Beaucouzé, France.
| | - Franck Bertolla
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
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Lee YA, Yang PY, Huang SC. Characterization, Phylogeny, and Genome Analyses of Nonpathogenic Xanthomonas campestris Strains Isolated from Brassica Seeds. PHYTOPATHOLOGY 2020; 110:981-988. [PMID: 32167850 DOI: 10.1094/phyto-08-19-0319-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Xanthomonads were detected by using the Xan-D(CCF) medium from the brassica seeds, and their pathogenicity was determined by plant inoculation tests. It was found that some seed lots were infested with Xanthomonas campestris pv. campestris, some with X. campestris pv. raphani, and some with nonpathogenic xanthomonads. The nonpathogenic xanthomonad strains were identified as X. campestris, and the multilocus sequence analysis showed that the nonpathogenic X. campestris strains were grouped together with pathogenic X. campestris, but not with nonpathogenic strains of X. arboricola. In addition, all isolated X. campestris pv. campestris and X. campestris pv. raphani strains were positive in the hrpF-PCR, but the nonpathogenic strains were negative. It was further found that nonpathogenic X. campestris strain nE1 does not contain the entire pathogenicity island (hrp gene cluster; type III secretion system) and all type III effector protein genes based on the whole genome sequence analyses. The nonpathogenic X. campestris strain nE1 could acquire the entire pathogenicity island from the endemic X. campestris pv. campestris and X. campestris pv. raphani strains by conjugation, but type III effector genes were not cotransferred. The studies showed that the nonpathogenic X. campestris strains indeed exist on the brassica seeds, but it could be differentiated by the PCR assays on the hrp and type III effector genes. Nevertheless, the nonpathogenic X. campestris strains cannot be ignored because they may be potential gene resources to increase genetic diversity in the endemic pathogenic X. campestris pv. campestris and X. campestris pv. raphani strains.
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Affiliation(s)
- Yung-An Lee
- Department of Life Science, Fu Jen Catholic University, Xin-Zhuang District, New Taipei City, Taiwan, Republic of China
| | - Pei-Yu Yang
- Department of Life Science, Fu Jen Catholic University, Xin-Zhuang District, New Taipei City, Taiwan, Republic of China
| | - Shau-Chang Huang
- Department of Life Science, Fu Jen Catholic University, Xin-Zhuang District, New Taipei City, Taiwan, Republic of China
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35
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Timilsina S, Potnis N, Newberry EA, Liyanapathiranage P, Iruegas-Bocardo F, White FF, Goss EM, Jones JB. Xanthomonas diversity, virulence and plant-pathogen interactions. Nat Rev Microbiol 2020; 18:415-427. [PMID: 32346148 DOI: 10.1038/s41579-020-0361-8] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2020] [Indexed: 12/19/2022]
Abstract
Xanthomonas spp. encompass a wide range of plant pathogens that use numerous virulence factors for pathogenicity and fitness in plant hosts. In this Review, we examine recent insights into host-pathogen co-evolution, diversity in Xanthomonas populations and host specificity of Xanthomonas spp. that have substantially improved our fundamental understanding of pathogen biology. We emphasize the virulence factors in xanthomonads, such as type III secreted effectors including transcription activator-like effectors, type II secretion systems, diversity resulting in host specificity, evolution of emerging strains, activation of susceptibility genes and strategies of host evasion. We summarize the genomic diversity in several Xanthomonas spp. and implications for disease outbreaks, management strategies and breeding for disease resistance.
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Affiliation(s)
- Sujan Timilsina
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Neha Potnis
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Eric A Newberry
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | | | | | - Frank F White
- Plant Pathology Department, University of Florida, Gainesville, FL, USA
| | - Erica M Goss
- Plant Pathology Department, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
| | - Jeffrey B Jones
- Plant Pathology Department, University of Florida, Gainesville, FL, USA.
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36
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Cohen SP, Luna EK, Lang JM, Ziegle J, Chang C, Leach JE, Le-Saux MF, Portier P, Koebnik R, Jacobs JM. High-Quality Genome Resource of Xanthomonas hyacinthi Generated via Long-Read Sequencing. PLANT DISEASE 2020; 104:1011-1012. [PMID: 32065568 DOI: 10.1094/pdis-11-19-2393-a] [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
The bacterial plant pathogen Xanthomonas hyacinthi is the causal agent of yellow disease of Hyacinthus and other ornamental plant genera. There is no available complete genome for X. hyacinthi, limiting basic research for this pathogen. Here, we release a high-quality complete genome sequence for the X. hyacinthi type strain, CFBP 1156. Single-molecule real-time (SMRT) sequencing with a mean coverage of 306× revealed two contigs of 4,918,645 and 44,381 bp in size. This was the first characterized plant-disease-causing species of Xanthomonas and this genome provides a resource to better understand the biology of yellow disease of hyacinth.
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Affiliation(s)
- Stephen P Cohen
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Emily K Luna
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Jillian M Lang
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Janet Ziegle
- Pacific Biosciences, Menlo Park, CA 94025, U.S.A
| | | | - Jan E Leach
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523, U.S.A
| | - Marion Fischer Le-Saux
- IRHS, Institut National de la Recherche Agronomique (INRA), Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSav, 49071, Beaucouzé, France
- CIRM-CFBP French Collection for Plant-associated Bacteria, IRHS, UMR 1345, INRA-ACO-UA, 42 rue Georges Morel, 49070, Beaucouzé, France
| | - Perrine Portier
- IRHS, Institut National de la Recherche Agronomique (INRA), Université d'Angers, Agrocampus-Ouest, SFR 4207 QuaSav, 49071, Beaucouzé, France
- CIRM-CFBP French Collection for Plant-associated Bacteria, IRHS, UMR 1345, INRA-ACO-UA, 42 rue Georges Morel, 49070, Beaucouzé, France
| | - Ralf Koebnik
- Institut de Recherche pour le Développement (IRD), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Université Montpellier, IPME, 34000 Montpellier, France
| | - Jonathan M Jacobs
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
- Infectious Disease Institute, The Ohio State University, Columbus, OH 43210, U.S.A
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37
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Comparative Genomics and Phylogenetic Analyses Suggest Several Novel Species within the Genus Clavibacter, Including Nonpathogenic Tomato-Associated Strains. Appl Environ Microbiol 2020; 86:AEM.02873-19. [PMID: 31924620 DOI: 10.1128/aem.02873-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/07/2020] [Indexed: 02/06/2023] Open
Abstract
Members of the genus Clavibacter are economically important bacterial plant pathogens infecting a set of diverse agricultural crops (e.g., alfalfa, corn, potato, tomato, and wheat). Tomato-associated Clavibacter sp. strains account for a great portion of the genetic diversity of the genus, and C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis), causing bacterial canker disease, is considered one of the most destructive seed-borne agents for the crop worldwide. However, current taxonomic descriptions of the genus do not reflect the existing diversity of the strains, resulting in unsatisfactory results in quarantine surveys for the pathogens. In this study, we used all the available genome sequences of Clavibacter sp. strains, including the type strains of newly described subspecies, to provide precise insight into the diversity of tomato-associated members of the genus and further clarify the taxonomic status of the strains using genotypic and phenotypic features. The results of phylogenetic analyses revealed the existence of nine hypothetical new species among the investigated strains. None of the three new subspecies (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) is included within the tomato-pathogenic C. michiganensis sensu stricto lineage. Although comparative genomics revealed the lack of chp and tomA pathogenicity determinant gene clusters in the nonpathogenic strains, a number of pathogenicity-related genes were noted to be present in all the strains regardless of their pathogenicity characteristics. Altogether, our results indicate a need for a formal taxonomic reconsideration of tomato-associated Clavibacter sp. strains to facilitate differentiation of the lineages in quarantine inspections.IMPORTANCE Clavibacter spp. are economically important bacterial plant pathogens infecting a set of diverse agricultural crops, such as alfalfa, corn, pepper, potato, tomato, and wheat. A number of plant-pathogenic members of the genus (e.g., C. michiganensis sensu stricto and C. sepedonicus, infecting tomato and potato plants, respectively) are included in the A2 (high-risk) list of quarantine pathogens by the European and Mediterranean Plant Protection Organization (EPPO). Although tomato-associated members of Clavibacter spp. account for a significant portion of the genetic diversity in the genus, only the strains belonging to C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis) cause bacterial canker disease of tomato and are subjected to the quarantine inspections. Hence, discrimination between the pathogenic and nonpathogenic Clavibacter sp. strains associated with tomato seeds and transplants plays a pivotal role in the accurate detection and cost-efficient management of the disease. On the other hand, detailed information on the genetic contents of different lineages of the genus would lead to the development of genome-informed specific detection techniques. In this study, we have provided an overview of the phylogenetic and genomic differences between the pathogenic and nonpathogenic tomato-associated Clavibacter sp. strains. We also noted that the taxonomic status of newly introduced subspecies of C. michiganensis (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) should be reconsidered.
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Méline V, Brin C, Lebreton G, Ledroit L, Sochard D, Hunault G, Boureau T, Belin E. A Computation Method Based on the Combination of Chlorophyll Fluorescence Parameters to Improve the Discrimination of Visually Similar Phenotypes Induced by Bacterial Virulence Factors. FRONTIERS IN PLANT SCIENCE 2020; 11:213. [PMID: 32174949 PMCID: PMC7055487 DOI: 10.3389/fpls.2020.00213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 02/11/2020] [Indexed: 05/24/2023]
Abstract
Phenotyping biotic stresses in plant-pathogen interactions studies is often hindered by phenotypes that can hardly be discriminated by visual assessment. Particularly, single gene mutants in virulence factors could lack visible phenotypes. Chlorophyll fluorescence (CF) imaging is a valuable tool to monitor plant-pathogen interactions. However, while numerous CF parameters can be measured, studies on plant-pathogen interactions often focus on a restricted number of parameters. It could result in limited abilities to discriminate visually similar phenotypes. In this study, we assess the ability of the combination of multiple CF parameters to improve the discrimination of such phenotypes. Such an approach could be of interest for screening and discriminating the impact of bacterial virulence factors without prior knowledge. A computation method was developed, based on the combination of multiple CF parameters, without any parameter selection. It involves histogram Bhattacharyya distance calculations and hierarchical clustering, with a normalization approach to take into account the inter-leaves and intra-phenotypes heterogeneities. To assess the efficiency of the method, two datasets were analyzed the same way. The first dataset featured single gene mutants of a Xanthomonas strain which differed only by their abilities to secrete bacterial virulence proteins. This dataset displayed expected phenotypes at 6 days post-inoculation and was used as ground truth dataset to setup the method. The efficiency of the computation method was demonstrated by the relevant discrimination of phenotypes at 3 days post-inoculation. A second dataset was composed of transient expression (agrotransformation) of Type 3 Effectors. This second dataset displayed phenotypes that cannot be discriminated by visual assessment and no prior knowledge can be made on the respective impact of each Type 3 Effectors on leaf tissues. Using the computation method resulted in clustering the leaf samples according to the Type 3 Effectors, thereby demonstrating an improvement of the discrimination of the visually similar phenotypes. The relevant discrimination of visually similar phenotypes induced by bacterial strains differing only by one virulence factor illustrated the importance of using a combination of CF parameters to monitor plant-pathogen interactions. It opens a perspective for the identification of specific signatures of biotic stresses.
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Affiliation(s)
- Valérian Méline
- Emersys, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- ImHorPhen, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Chrystelle Brin
- Emersys, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Guillaume Lebreton
- Phenotic Platform, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Lydie Ledroit
- Phenotic Platform, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Daniel Sochard
- Phenotic Platform, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Gilles Hunault
- ImHorPhen, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- Laboratoire HIFIH, UPRES EA 3859, SFR 4208, Université d'Angers, Angers, France
| | - Tristan Boureau
- Emersys, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- ImHorPhen, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- Phenotic Platform, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
| | - Etienne Belin
- ImHorPhen, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- Phenotic Platform, SFR 4207 QUASAV, IRHS, UMR1345, Université d'Angers, Angers, France
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes, Université d'Angers, Angers, France
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Garita-Cambronero J, Sena-Vélez M, Ferragud E, Sabuquillo P, Redondo C, Cubero J. Xanthomonas citri subsp. citri and Xanthomonas arboricola pv. pruni: Comparative analysis of two pathogens producing similar symptoms in different host plants. PLoS One 2019; 14:e0219797. [PMID: 31318915 PMCID: PMC6639005 DOI: 10.1371/journal.pone.0219797] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/01/2019] [Indexed: 01/06/2023] Open
Abstract
Comparative studies in Xanthomonas have provided a vast amount of data that enabled to deepen in the knowledge of those factors associated with virulence and Xanthomonas plant interaction. The species of this genus present a wide range of host plants and a large number of studies have been focused to elucidate which mechanism are involved in this characteristic. In this study, comparative genomic and phenotypic analysis were performed between X. citri subsp. citri (Xcc), one of the most studied pathogens within Xanthomonas, and X. arboricola pv. pruni (Xap), a pathogen which has aroused great interest in recent time. The work was aimed to find those elements that contribute to their host divergence despite the convergence in the symptoms that each species cause on Citrus spp. and Prunus spp., respectively. This study reveals a set of genes that could be putatively associated with the adaptation of these pathogens to their hosts, being the most remarkable those involved in environmental sensing systems such as the case of the TonB-dependent transporters, the sensors of the two-component system and the methyl accepting chemotaxis proteins. Other important variants were found in processes related to the decomposition of the cell wall as could be appreciated by their dissimilar set of cell-wall degrading enzymes. Type three effectors, as one of the most important factors in delineating the host specificity in Xanthomonas, also showed a different array when comparing both species, being some of them unique to each pathogen. On the other hand, only small variations could be connected to other features such as the motility appendages and surface adhesion proteins, but these differences were accompanied by a dissimilar capacity to attach on host and non-host leaf surface. The molecular factors found in this work provide the basis to perform a more in-depth functional analyses that unveil those actual factors associated with pathogenesis and host specificity in Xcc and Xap.
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Affiliation(s)
- Jerson Garita-Cambronero
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain.,Centro de Investigación de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León (ITACyL), Villarejo de Órbigo, Leon, Spain
| | - Marta Sena-Vélez
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain.,Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Elisa Ferragud
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Pilar Sabuquillo
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Cristina Redondo
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
| | - Jaime Cubero
- Departamento de Protección Vegetal, Laboratorio Bacteriología, Instituto Nacional de Investigación y Tecnología Agraria (INIA), Madrid, Spain
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Rangel LT, Marden J, Colston S, Setubal JC, Graf J, Gogarten JP. Identification and characterization of putative Aeromonas spp. T3SS effectors. PLoS One 2019; 14:e0214035. [PMID: 31163020 PMCID: PMC6548356 DOI: 10.1371/journal.pone.0214035] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 05/21/2019] [Indexed: 11/23/2022] Open
Abstract
The genetic determinants of bacterial pathogenicity are highly variable between species and strains. However, a factor that is commonly associated with virulent Gram-negative bacteria, including many Aeromonas spp., is the type 3 secretion system (T3SS), which is used to inject effector proteins into target eukaryotic cells. In this study, we developed a bioinformatics pipeline to identify T3SS effector proteins, applied this approach to the genomes of 105 Aeromonas strains isolated from environmental, mutualistic, or pathogenic contexts and evaluated the cytotoxicity of the identified effectors through their heterologous expression in yeast. The developed pipeline uses a two-step approach, where candidate Aeromonas gene families are initially selected using Hidden Markov Model (HMM) profile searches against the Virulence Factors DataBase (VFDB), followed by strict comparisons against positive and negative control datasets, greatly reducing the number of false positives. This approach identified 21 Aeromonas T3SS likely effector families, of which 8 represent known or characterized effectors, while the remaining 13 have not previously been described in Aeromonas. We experimentally validated our in silico findings by assessing the cytotoxicity of representative effectors in Saccharomyces cerevisiae BY4741, with 15 out of 21 assayed proteins eliciting a cytotoxic effect in yeast. The results of this study demonstrate the utility of our approach, combining a novel in silico search method with in vivo experimental validation, and will be useful in future research aimed at identifying and authenticating bacterial effector proteins from other genera.
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Affiliation(s)
- Luiz Thiberio Rangel
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Jeremiah Marden
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Sophie Colston
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
| | - João Carlos Setubal
- Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brasil
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brasil
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail: (JPG); (JG)
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, United States of America
- Institute for Systems Genomics, University of Connecticut, Storrs, Connecticut, United States of America
- * E-mail: (JPG); (JG)
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Meline V, Delage W, Brin C, Li‐Marchetti C, Sochard D, Arlat M, Rousseau C, Darrasse A, Briand M, Lebreton G, Portier P, Fischer‐Le Saux M, Durand K, Jacques M, Belin E, Boureau T. Role of the acquisition of a type 3 secretion system in the emergence of novel pathogenic strains of Xanthomonas. MOLECULAR PLANT PATHOLOGY 2019; 20:33-50. [PMID: 30076773 PMCID: PMC6430459 DOI: 10.1111/mpp.12737] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cases of emergence of novel plant-pathogenic strains are regularly reported that reduce the yields of crops and trees. However, the molecular mechanisms underlying such emergence are still poorly understood. The acquisition by environmental non-pathogenic strains of novel virulence genes by horizontal gene transfer has been suggested as a driver for the emergence of novel pathogenic strains. In this study, we tested such an hypothesis by transferring a plasmid encoding the type 3 secretion system (T3SS) and four associated type 3 secreted proteins (T3SPs) to the non-pathogenic strains of Xanthomonas CFBP 7698 and CFBP 7700, which lack genes encoding T3SS and any previously known T3SPs. The resulting strains were phenotyped on Nicotiana benthamiana using chlorophyll fluorescence imaging and image analysis. Wild-type, non-pathogenic strains induced a hypersensitive response (HR)-like necrosis, whereas strains complemented with T3SS and T3SPs suppressed this response. Such suppression depends on a functional T3SS. Amongst the T3SPs encoded on the plasmid, Hpa2, Hpa1 and, to a lesser extent, XopF1 collectively participate in suppression. Monitoring of the population sizes in planta showed that the sole acquisition of a functional T3SS by non-pathogenic strains impairs growth inside leaf tissues. These results provide functional evidence that the acquisition via horizontal gene transfer of a T3SS and four T3SPs by environmental non-pathogenic strains is not sufficient to make strains pathogenic. In the absence of a canonical effector, the sole acquisition of a T3SS seems to be counter-selective, and further acquisition of type 3 effectors is probably needed to allow the emergence of novel pathogenic strains.
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Affiliation(s)
- Valérian Meline
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Wesley Delage
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Chrystelle Brin
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Camille Li‐Marchetti
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Daniel Sochard
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Matthieu Arlat
- INRAUMR 441, Laboratoire des Interactions Plantes Micro‐organismes (LIPM)F‐31326Castanet‐TolosanFrance
| | - Céline Rousseau
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Armelle Darrasse
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Martial Briand
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Guillaume Lebreton
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Perrine Portier
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- CIRM‐CFBP French Collection for Plant‐associated BacteriaIRHSUMR 1345INRA‐ACO‐UA42 rue Georges Morel49070Beaucouzé CedexFrance
| | - Marion Fischer‐Le Saux
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- CIRM‐CFBP French Collection for Plant‐associated BacteriaIRHSUMR 1345INRA‐ACO‐UA42 rue Georges Morel49070Beaucouzé CedexFrance
| | - Karine Durand
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Marie‐Agnès Jacques
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
| | - Etienne Belin
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS)Université d’AngersF‐49000AngersFrance
| | - Tristan Boureau
- IRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
- Platform PHENOTICIRHSINRA, Université d’AngersAgrocampus‐OuestSFR 4207 QuaSav49071BeaucouzéFrance
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Nagel R, Bieber JE, Schmidt-Dannert MG, Nett RS, Peters RJ. A Third Class: Functional Gibberellin Biosynthetic Operon in Beta-Proteobacteria. Front Microbiol 2018; 9:2916. [PMID: 30546353 PMCID: PMC6278637 DOI: 10.3389/fmicb.2018.02916] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/13/2018] [Indexed: 11/13/2022] Open
Abstract
The ability of plant-associated microbes to produce gibberellin A (GA) phytohormones was first described for the fungal rice pathogen Gibberella fujikuroi in the 1930s. Recently the capacity to produce GAs was shown for several bacteria, including symbiotic alpha-proteobacteria (α-rhizobia) and gamma-proteobacteria phytopathogens. All necessary enzymes for GA production are encoded by a conserved operon, which appears to have undergone horizontal transfer between and within these two phylogenetic classes of bacteria. Here the operon was shown to be present and functional in a third class, the beta-proteobacteria, where it is found in several symbionts (β-rhizobia). Conservation of function was examined by biochemical characterization of the enzymes encoded by the operon from Paraburkholderia mimosarum LMG 23256T. Despite the in-frame gene fusion between the short-chain alcohol dehydrogenase/reductase and ferredoxin, the encoded enzymes exhibited the expected activity. Intriguingly, together these can only produce GA9, the immediate precursor to the bioactive GA4, as the cytochrome P450 (CYP115) that catalyzes the final hydroxylation reaction is missing, similar to most α-rhizobia. However, phylogenetic analysis indicates that the operon from β-rhizobia is more closely related to examples from gamma-proteobacteria, which almost invariably have CYP115 and, hence, can produce bioactive GA4. This indicates not only that β-rhizobia acquired the operon by horizontal gene transfer from gamma-proteobacteria, rather than α-rhizobia, but also that they independently lost CYP115 in parallel to the α-rhizobia, further hinting at the possibility of detrimental effects for the production of bioactive GA4 by these symbionts.
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Affiliation(s)
- Raimund Nagel
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
| | - John E Bieber
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States.,Science Department, Newton Senior High School, Newton, IA, United States
| | - Mark G Schmidt-Dannert
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Ryan S Nett
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Reuben J Peters
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
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Timilsina S, Kara S, Jacques MA, Potnis N, Minsavage GV, Vallad GE, Jones JB, Fischer-Le Saux M. Reclassification of Xanthomonas gardneri (ex Šutič 1957) Jones et al. 2006 as a later heterotypic synonym of Xanthomonas cynarae Trébaol et al. 2000 and description of X. cynarae pv. cynarae and X. cynarae pv. gardneri based on whole genome analyses. Int J Syst Evol Microbiol 2018; 69:343-349. [PMID: 30457512 DOI: 10.1099/ijsem.0.003104] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multilocus sequence analysis of Xanthomonas species revealed a very close relationship between Xanthomonas cynarae, an artichoke pathogen and Xanthomonas gardneri, a tomato and pepper pathogen. Results of whole genome sequence comparisons using average nucleotide identity between representative strains of X. gardneri and X. cynarae were well above the threshold of 95-96 %. Inoculations of X. gardneri strains in artichoke leaves caused mild disease symptoms, but only weak symptoms were observed in the bracts. Both X. cynarae and X. gardneri grew equally and caused typical bacterial spot symptoms in pepper after artificial inoculation. However, X. cynarae induced a hypersensitive reaction in tomato, while X. gardneri strains were virulent. Pathogenicity-associated gene clusters, including the protein secretion systems, type III effector profiles, and lipopolysaccharide cluster were nearly identical between the two species. Based on our results from whole genome sequence comparison, X. gardneri and X. cynarae belong to the same species. The name X. cynarae has priority and X. gardneri should be considered as a later heterotypic synonym. An emended description of X. cynarae (type strain=CFBP 4188T, =DSM 16794T) is given. However, due to the host specificity in artichoke and tomato, two pathovars, X. cynarae pv. cynarae and X. cynarae pv. gardneri, are proposed.
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Affiliation(s)
- S Timilsina
- 1Plant Pathology Department, University of Florida, Gainesville, FL, 32611, USA
| | - S Kara
- 1Plant Pathology Department, University of Florida, Gainesville, FL, 32611, USA.,2Diyarbakır Plant Protection Research Institute, Silvan Highway 7. Km. 21110, Diyarbakır, Turkey
| | - M A Jacques
- 3IRHS, INRA, Agrocampus-Ouest, Université d'Angers, SFR 4207 QUASAV, 49070 Beaucouzé, France
| | - N Potnis
- 4Entomology and Plant Pathology Department, Auburn University, Auburn, AL, 36849, USA
| | - G V Minsavage
- 1Plant Pathology Department, University of Florida, Gainesville, FL, 32611, USA
| | - G E Vallad
- 5University of Florida, Gulf Coast Research and Education Center, Balm, Florida, 33598, USA
| | - J B Jones
- 1Plant Pathology Department, University of Florida, Gainesville, FL, 32611, USA
| | - M Fischer-Le Saux
- 3IRHS, INRA, Agrocampus-Ouest, Université d'Angers, SFR 4207 QUASAV, 49070 Beaucouzé, France
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44
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López MM, Lopez-Soriano P, Garita-Cambronero J, Beltrán C, Taghouti G, Portier P, Cubero J, Fischer-Le Saux M, Marco-Noales E. Xanthomonas prunicola sp. nov., a novel pathogen that affects nectarine (Prunus persica var. nectarina) trees. Int J Syst Evol Microbiol 2018; 68:1857-1866. [PMID: 29741474 DOI: 10.1099/ijsem.0.002743] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Three isolates obtained from symptomatic nectarine trees (Prunus persica var. nectarina) cultivated in Murcia, Spain, which showed yellow and mucoid colonies similar to Xanthomonas arboricola pv. pruni, were negative after serological and real-time PCR analyses for this pathogen. For that reason, these isolates were characterized following a polyphasic approach that included both phenotypic and genomic methods. By sequence analysis of the 16S rRNA gene, these novel strains were identified as members of the genus Xanthomonas, and by multilocus sequence analysis (MLSA) they were clustered together in a distinct group that showed similarity values below 95 % with the rest of the species of this genus. Whole-genome comparisons of the average nucleotide identity (ANI) of genomes of the strains showed less than 91 % average nucleotide identity with all other species of the genus Xanthomonas. Additionally, phenotypic characterization based on API 20 NE, API 50 CH and BIOLOG tests differentiated the strains from the species of the genus Xanthomonas described previously. Moreover, the three strains were confirmed to be pathogenic on peach (Prunus persica), causing necrotic lesions on leaves. On the basis of these results, the novel strains represent a novel species of the genus Xanthomonas, for which the name Xanthomonas prunicola is proposed. The type strain is CFBP 8353 (=CECT 9404=IVIA 3287.1).
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Affiliation(s)
- María M López
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Carretera CV-315 Km 10,7, 46113 Moncada, Valencia, Spain
| | - Pablo Lopez-Soriano
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Carretera CV-315 Km 10,7, 46113 Moncada, Valencia, Spain
| | - Jerson Garita-Cambronero
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Carretera de la Coruña Km 7,5, 28040 Madrid, Spain.,Centro de Investigación de Biocombustibles y Bioproductos, Instituto Tecnológico Agrario de Castilla y León, 24358 Villarejo de Orbigo, León, Spain
| | - Carmen Beltrán
- Consejería de Agricultura y Agua. Comunidad Autónoma Región de Murcia, Calle Mayor s/n, 30150 La Alberca, Murcia, Spain
| | - Geraldine Taghouti
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, CIRM-CFBP, 42 rue Georges Morel, 49071 Beaucouzé cedex, France
| | - Perrine Portier
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, CIRM-CFBP, 42 rue Georges Morel, 49071 Beaucouzé cedex, France
| | - Jaime Cubero
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Carretera de la Coruña Km 7,5, 28040 Madrid, Spain
| | - Marion Fischer-Le Saux
- IRHS, INRA, AGROCAMPUS-Ouest, Université d'Angers, SFR 4207 QUASAV, CIRM-CFBP, 42 rue Georges Morel, 49071 Beaucouzé cedex, France
| | - Ester Marco-Noales
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Carretera CV-315 Km 10,7, 46113 Moncada, Valencia, Spain
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Merda D, Briand M, Bosis E, Rousseau C, Portier P, Barret M, Jacques MA, Fischer-Le Saux M. Ancestral acquisitions, gene flow and multiple evolutionary trajectories of the type three secretion system and effectors in Xanthomonas plant pathogens. Mol Ecol 2017; 26:5939-5952. [PMID: 28869687 PMCID: PMC7168496 DOI: 10.1111/mec.14343] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/03/2017] [Accepted: 08/05/2017] [Indexed: 12/13/2022]
Abstract
Deciphering the evolutionary history and transmission patterns of virulence determinants is necessary to understand the emergence of novel pathogens. The main virulence determinant of most pathogenic proteobacteria is the type three secretion system (T3SS). The Xanthomonas genus includes bacteria responsible for numerous epidemics in agroecosystems worldwide and represents a major threat to plant health. The main virulence factor of Xanthomonas is the Hrp2 family T3SS; however, this system is not conserved in all strains and it has not been previously determined whether the distribution of T3SS in this bacterial genus has resulted from losses or independent acquisitions. Based on comparative genomics of 82 genome sequences representing the diversity of the genus, we have inferred three ancestral acquisitions of the Hrp2 cluster during Xanthomonas evolution followed by subsequent losses in some commensal strains and re‐acquisition in some species. While mutation was the main force driving polymorphism at the gene level, interspecies homologous recombination of large fragments expanding through several genes shaped Hrp2 cluster polymorphism. Horizontal gene transfer of the entire Hrp2 cluster also occurred. A reduced core effectome composed of xopF1, xopM, avrBs2 and xopR was identified that may allow commensal strains overcoming plant basal immunity. In contrast, stepwise accumulation of numerous type 3 effector genes was shown in successful pathogens responsible for epidemics. Our data suggest that capacity to intimately interact with plants through T3SS would be an ancestral trait of xanthomonads. Since its acquisition, T3SS has experienced a highly dynamic evolutionary history characterized by intense gene flux between species that may reflect its role in host adaptation.
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Affiliation(s)
- Déborah Merda
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
| | - Martial Briand
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
| | - Eran Bosis
- Department of Biotechnology Engineering, ORT Braude College, Karmiel, Israel
| | - Céline Rousseau
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
| | - Perrine Portier
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
| | - Matthieu Barret
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
| | - Marie-Agnès Jacques
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, Beaucouzé, France
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