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Vadillo‐Dieguez A, Zeng Z, Mansfield JW, Grinberg NF, Lynn SC, Gregg A, Connell J, Harrison RJ, Jackson RW, Hulin MT. Genetic dissection of the tissue-specific roles of type III effectors and phytotoxins in the pathogenicity of Pseudomonas syringae pv. syringae to cherry. Mol Plant Pathol 2024; 25:e13451. [PMID: 38590135 PMCID: PMC11002349 DOI: 10.1111/mpp.13451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/13/2024] [Accepted: 03/19/2024] [Indexed: 04/10/2024]
Abstract
When compared with other phylogroups (PGs) of the Pseudomonas syringae species complex, P. syringae pv. syringae (Pss) strains within PG2 have a reduced repertoire of type III effectors (T3Es) but produce several phytotoxins. Effectors within the cherry pathogen Pss 9644 were grouped based on their frequency in strains from Prunus as the conserved effector locus (CEL) common to most P. syringae pathogens; a core of effectors common to PG2; a set of PRUNUS effectors common to cherry pathogens; and a FLEXIBLE set of T3Es. Pss 9644 also contains gene clusters for biosynthesis of toxins syringomycin, syringopeptin and syringolin A. After confirmation of virulence gene expression, mutants with a sequential series of T3E and toxin deletions were pathogenicity tested on wood, leaves and fruits of sweet cherry (Prunus avium) and leaves of ornamental cherry (Prunus incisa). The toxins had a key role in disease development in fruits but were less important in leaves and wood. An effectorless mutant retained some pathogenicity to fruit but not wood or leaves. Striking redundancy was observed amongst effector groups. The CEL effectors have important roles during the early stages of leaf infection and possibly acted synergistically with toxins in all tissues. Deletion of separate groups of T3Es had more effect in P. incisa than in P. avium. Mixed inocula were used to complement the toxin mutations in trans and indicated that strain mixtures may be important in the field. Our results highlight the niche-specific role of toxins in P. avium tissues and the complexity of effector redundancy in the pathogen Pss 9644.
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Affiliation(s)
- Andrea Vadillo‐Dieguez
- NIABCambridgeUK
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
| | | | | | | | | | | | | | - Richard J. Harrison
- NIABCambridgeUK
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
- Faculty of Natural Sciences, Plant Science GroupWageningen University and ResearchWageningenNetherlands
- Present address:
Faculty of Natural Sciences, Plant Science GroupWageningen University and ResearchWageningenNetherlands
| | - Robert W. Jackson
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamUK
| | - Michelle T. Hulin
- NIABCambridgeUK
- Department of Plant Soil & Microbial SciencesMichigan State UniversityEast LansingUSA
- Present address:
Department of Plant Soil & Microbial SciencesMichigan State UniversityEast LansingUSA
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2
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Buonaurio R, Moretti C, Catara V, Hulin MT, Sessa G, Sundin GW. Editorial: Molecular interactions between bacterial pathogens and plants: selected contributions to the 14th International Conference on Plant Pathogenic Bacteria (14th ICPPB). Front Plant Sci 2023; 14:1345785. [PMID: 38146274 PMCID: PMC10749295 DOI: 10.3389/fpls.2023.1345785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023]
Affiliation(s)
- Roberto Buonaurio
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy
| | - Chiaraluce Moretti
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, Perugia, Italy
| | - Vittoria Catara
- Department of Agriculture, Food and Environment, University of Catania, Catania, Italy
| | - Michelle T. Hulin
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Guido Sessa
- School of Plant Sciences and Food Security, Tel-Aviv University, Tel-Aviv, Israel
| | - George W. Sundin
- Department of Plant Soil & Microbial Sci, Michigan State University, E Lansing, MI, United States
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3
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Tang B, Feng L, Hulin MT, Ding P, Ma W. Cell-type-specific responses to fungal infection in plants revealed by single-cell transcriptomics. Cell Host Microbe 2023; 31:1732-1747.e5. [PMID: 37741284 DOI: 10.1016/j.chom.2023.08.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/14/2023] [Accepted: 08/29/2023] [Indexed: 09/25/2023]
Abstract
Pathogen infection is a dynamic process. Here, we employ single-cell transcriptomics to investigate plant response heterogeneity. By generating an Arabidopsis thaliana leaf atlas encompassing 95,040 cells during infection by a fungal pathogen, Colletotrichum higginsianum, we unveil cell-type-specific gene expression, notably an enrichment of intracellular immune receptors in vasculature cells. Trajectory inference identifies cells that had different interactions with the invading fungus. This analysis divulges transcriptional reprogramming of abscisic acid signaling specifically occurring in guard cells, which is consistent with a stomatal closure dependent on direct contact with the fungus. Furthermore, we investigate the transcriptional plasticity of genes involved in glucosinolate biosynthesis in cells at the fungal infection sites, emphasizing the contribution of the epidermis-expressed MYB122 to disease resistance. This work underscores spatially dynamic, cell-type-specific plant responses to a fungal pathogen and provides a valuable resource that supports in-depth investigations of plant-pathogen interactions.
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Affiliation(s)
- Bozeng Tang
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, NR4 7UH Norwich, UK
| | - Li Feng
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, NR4 7UH Norwich, UK
| | - Michelle T Hulin
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, NR4 7UH Norwich, UK
| | - Pingtao Ding
- Institute of Biology Leiden, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, NR4 7UH Norwich, UK.
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Abstract
Effectors play a central role in determining the outcome of plant-pathogen interactions. As key virulence proteins, effectors are collectively indispensable for disease development. By understanding the virulence mechanisms of effectors, fundamental knowledge of microbial pathogenesis and disease resistance have been revealed. Effectors are also considered double-edged swords because some of them activate immunity in disease resistant plants after being recognized by specific immune receptors, which evolved to monitor pathogen presence or activity. Characterization of effector recognition by their cognate immune receptors and the downstream immune signaling pathways is instrumental in implementing resistance. Over the past decades, substantial research effort has focused on effector biology, especially concerning their interactions with virulence targets or immune receptors in plant cells. A foundation of this research is robust identification of the effector repertoire from a given pathogen, which depends heavily on bioinformatic prediction. In this review, we summarize methodologies that have been used for effector mining in various microbial pathogens which use different effector delivery mechanisms. We also discuss current limitations and provide perspectives on how recently developed analytic tools and technologies may facilitate effector identification and hence generation of a more complete vision of host-pathogen interactions. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
| | - Sara Dorhmi
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
- Department of Microbiology and Plant Pathology, University of California Riverside, CA 92521, U.S.A
| | | | - Yufei Li
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
| | - John W Mansfield
- Faculty of Natural Sciences, Imperial College London, London, SW7 2BX, U.K
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
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5
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Hulin MT, Rabiey M, Zeng Z, Vadillo Dieguez A, Bellamy S, Swift P, Mansfield JW, Jackson RW, Harrison RJ. Genomic and functional analysis of phage-mediated horizontal gene transfer in Pseudomonas syringae on the plant surface. New Phytol 2023; 237:959-973. [PMID: 36285389 PMCID: PMC10107160 DOI: 10.1111/nph.18573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Many strains of Pseudomonas colonise plant surfaces, including the cherry canker pathogens, Pseudomonas syringae pathovars syringae and morsprunorum. We have examined the genomic diversity of P. syringae in the cherry phyllosphere and focused on the role of prophages in transfer of genes encoding Type 3 secreted effector (T3SE) proteins contributing to the evolution of virulence. Phylogenomic analysis was carried out on epiphytic pseudomonads in the UK orchards. Significant differences in epiphytic populations occurred between regions. Nonpathogenic strains were found to contain reservoirs of T3SE genes. Members of P. syringae phylogroups 4 and 10 were identified for the first time from Prunus. Using bioinformatics, we explored the presence of the gene encoding T3SE HopAR1 within related prophage sequences in diverse P. syringae strains including cherry epiphytes and pathogens. Results indicated that horizontal gene transfer (HGT) of this effector between phylogroups may have involved phage. Prophages containing hopAR1 were demonstrated to excise, circularise and transfer the gene on the leaf surface. The phyllosphere provides a dynamic environment for prophage-mediated gene exchange and the potential for the emergence of new more virulent pathotypes. Our results suggest that genome-based epidemiological surveillance of environmental populations will allow the timely application of control measures to prevent damaging diseases.
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Affiliation(s)
- Michelle T. Hulin
- NIABLawrence Weaver RoadCambridgeCB3 0LEUK
- The Sainsbury LaboratoryNorwichNR4 7UHUK
| | - Mojgan Rabiey
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamB15 2TTUK
| | - Ziyue Zeng
- NIABLawrence Weaver RoadCambridgeCB3 0LEUK
| | | | | | - Phoebe Swift
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamB15 2TTUK
| | | | - Robert W. Jackson
- School of Biosciences and the Birmingham Institute of Forest ResearchUniversity of BirminghamBirminghamB15 2TTUK
| | - Richard J. Harrison
- NIABLawrence Weaver RoadCambridgeCB3 0LEUK
- Present address:
Plant Science GroupWageningen University and ResearchWageningen6708WBthe Netherlands
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Hulin MT, Vadillo Dieguez A, Cossu F, Lynn S, Russell K, Neale HC, Jackson RW, Arnold DL, Mansfield JW, Harrison RJ. Identifying resistance in wild and ornamental cherry towards bacterial canker caused by Pseudomonas syringae. Plant Pathol 2022; 71:949-965. [PMID: 35909801 PMCID: PMC9305585 DOI: 10.1111/ppa.13513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 05/31/2023]
Abstract
Bacterial canker is a major disease of stone fruits and is a critical limiting factor to sweet cherry (Prunus avium) production worldwide. One important strategy for disease control is the development of resistant varieties. Partial varietal resistance in sweet cherry is discernible using shoot or whole tree inoculations; however, these quantitative differences in resistance are not evident in detached leaf assays. To identify novel sources of resistance to canker, we used a rapid leaf pathogenicity test to screen a range of wild cherry, ornamental Prunus species and sweet cherry × ornamental cherry hybrids with the canker pathogens, Pseudomonas syringae pvs syringae, morsprunorum races 1 and 2, and avii. Several Prunus accessions exhibited limited symptom development following inoculation with each of the pathogens, and this resistance extended to 16 P. syringae strains pathogenic on sweet cherry and plum. Resistance was associated with reduced bacterial multiplication after inoculation, a phenotype similar to that of commercial sweet cherry towards nonhost strains of P. syringae. Progeny resulting from a cross of a resistant ornamental species Prunus incisa with susceptible sweet cherry (P. avium) exhibited resistance indicating it is an inherited trait. Identification of accessions with resistance to the major bacterial canker pathogens is the first step towards characterizing the underlying genetic mechanisms of resistance and introducing these traits into commercial germplasm.
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Affiliation(s)
- Michelle T. Hulin
- NIAB EMREast MallingUK
- Present address:
The Sainsbury LaboratoryNorwichUK
| | | | | | | | | | - Helen C. Neale
- Centre for Research in BioscienceFaculty of Health and Applied SciencesThe University of the West of EnglandFrenchay CampusBristolUK
| | - Robert W. Jackson
- Birmingham Institute of Forest Research (BIFoR)University of BirminghamBirminghamUK
- School of BiosciencesUniversity of BirminghamBirminghamUK
| | - Dawn L. Arnold
- Centre for Research in BioscienceFaculty of Health and Applied SciencesThe University of the West of EnglandFrenchay CampusBristolUK
- Harper Adams UniversityNewportShropshireUK
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Yuan X, Hulin MT, Sundin GW. Effectors, chaperones, and harpins of the Type III secretion system in the fire blight pathogen Erwinia amylovora: a review. J Plant Pathol 2021; 103:25-39. [PMID: 0 DOI: 10.1007/s42161-020-00623-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/23/2020] [Indexed: 05/20/2023]
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8
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Neale HC, Hulin MT, Harrison RJ, Jackson RW, Mansfield JW, Arnold DL. An improved conjugation method for Pseudomonas syringae. J Microbiol Methods 2020; 177:106025. [PMID: 32795634 DOI: 10.1016/j.mimet.2020.106025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 11/15/2022]
Abstract
In order to achieve saturating transposon mutagenesis of the genome of plant pathogenic strains of Pseudomonas syringae we needed to improve plasmid conjugation frequency. Manipulation of the growth stage of donor and recipient cells allowed the required increase in frequency and facilitated conjugation of otherwise recalcitrant strains.
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Affiliation(s)
- Helen C Neale
- Centre for Research in Bioscience, Faculty of Health and Applied Sciences, The University of the West of England, Frenchay Campus, Bristol BS16 1QY, UK
| | | | | | - Robert W Jackson
- Birmingham Institute of Forest Research (BIFoR), University of Birmingham, Birmingham, UK; School of Biosciences, University of Birmingham, Birmingham, UK
| | - John W Mansfield
- Faculty of Natural Sciences, Imperial College London, London, UK
| | - Dawn L Arnold
- Centre for Research in Bioscience, Faculty of Health and Applied Sciences, The University of the West of England, Frenchay Campus, Bristol BS16 1QY, UK; Harper Adams University, Newport, Shropshire TF10 8NB, UK.
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9
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Hulin MT, Jackson RW, Harrison RJ, Mansfield JW. Cherry picking by pseudomonads: After a century of research on canker, genomics provides insights into the evolution of pathogenicity towards stone fruits. Plant Pathol 2020; 69:962-978. [PMID: 32742023 PMCID: PMC7386918 DOI: 10.1111/ppa.13189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/09/2020] [Accepted: 03/23/2020] [Indexed: 05/10/2023]
Abstract
Bacterial canker disease is a major limiting factor in the growing of cherry and other Prunus species worldwide. At least five distinct clades within the bacterial species complex Pseudomonas syringae are known to be causal agents of the disease. The different pathogens commonly coexist in the field. Reducing canker is a challenging prospect as the efficacy of chemical controls and host resistance may vary against each of the diverse clades involved. Genomic analysis has revealed that the pathogens use a variable repertoire of virulence factors to cause the disease. Significantly, strains of P. syringae pv. syringae possess more genes for toxin biosynthesis and fewer encoding type III effector proteins. There is also a shared pool of key effector genes present on mobile elements such as plasmids and prophages that may have roles in virulence. By contrast, there is evidence that absence or truncation of certain effector genes, such as hopAB, is characteristic of cherry pathogens. Here we highlight how recent research, underpinned by the earlier epidemiological studies, is allowing significant progress in our understanding of the canker pathogens. This fundamental knowledge, combined with emerging insights into host genetics, provides the groundwork for development of precise control measures and informed approaches to breed for disease resistance.
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Affiliation(s)
| | - Robert W. Jackson
- Birmingham Institute of Forest Research (BIFoR), University of BirminghamBirminghamUK
- School of Biosciences, University of BirminghamBirminghamUK
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Taylor A, Armitage AD, Handy C, Jackson AC, Hulin MT, Harrison RJ, Clarkson JP. Basal Rot of Narcissus: Understanding Pathogenicity in Fusarium oxysporum f. sp. narcissi. Front Microbiol 2019; 10:2905. [PMID: 31921077 PMCID: PMC6930931 DOI: 10.3389/fmicb.2019.02905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 12/02/2019] [Indexed: 12/21/2022] Open
Abstract
Fusarium oxysporum is a globally distributed soilborne fungal pathogen causing root rots, bulb rots, crown rots and vascular wilts on a range of horticultural plants. Pathogenic F. oxysporum isolates are highly host specific and are classified as formae speciales. Narcissus is an important ornamental crop and both the quality and yield of flowers and bulbs can be severely affected by a basal rot caused by F. oxysporum f. sp. narcissi (FON); 154 Fusarium isolates were obtained from different locations and Narcissus cultivars in the United Kingdom, representing a valuable resource. A subset of 30 F. oxysporum isolates were all found to be pathogenic and were therefore identified as FON. Molecular characterisation of isolates through sequencing of three housekeeping genes, suggested a monophyletic origin with little divergence. PCR detection of 14 Secreted in Xylem (SIX) genes, previously shown to be associated with pathogenicity in other F. oxysporum f. spp., revealed different complements of SIX7, SIX9, SIX10, SIX12 and SIX13 within FON isolates which may suggest a race structure. SIX gene sequences were unique to FON and SIX10 was present in all isolates, allowing for molecular identification of FON for the first time. The genome of a highly pathogenic isolate was sequenced and lineage specific (LS) regions identified which harboured putative effectors including the SIX genes. Real-time RT-PCR, showed that SIX genes and selected putative effectors were expressed in planta with many significantly upregulated during infection. This is the first study to characterise molecular variation in FON and provide an analysis of the FON genome. Identification of expressed genes potentially associated with virulence provides the basis for future functional studies and new targets for molecular diagnostics.
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Affiliation(s)
- Andrew Taylor
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Warwick, United Kingdom
| | | | - Claire Handy
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Warwick, United Kingdom
| | - Alison C Jackson
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Warwick, United Kingdom
| | | | | | - John P Clarkson
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Warwick, United Kingdom
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Armitage AD, Taylor A, Hulin MT, Jackson AC, Harrison RJ, Clarkson JP. Draft Genome Sequence of an Onion Basal Rot Isolate of Fusarium proliferatum. Microbiol Resour Announc 2019; 8:e01385-18. [PMID: 30637390 PMCID: PMC6318361 DOI: 10.1128/mra.01385-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 11/19/2018] [Indexed: 11/20/2022] Open
Abstract
Fusarium proliferatum is a component of the onion basal rot disease complex. We present an annotated F. proliferatum draft genome sequence, totaling 45.8 Mb in size, assembled into 597 contigs, with a predicted 15,418 genes. The genome contains 58 secondary metabolite clusters and homologs of the Fusarium oxysporum effector SIX2.
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Affiliation(s)
| | - Andrew Taylor
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Wellesbourne, Warwick, United Kingdom
| | | | - Alison C. Jackson
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Wellesbourne, Warwick, United Kingdom
| | | | - John P. Clarkson
- Warwick Crop Centre, School of Life Sciences, University of Warwick, Wellesbourne, Warwick, United Kingdom
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Hulin MT, Armitage AD, Vicente JG, Holub EB, Baxter L, Bates HJ, Mansfield JW, Jackson RW, Harrison RJ. Comparative genomics of Pseudomonas syringae reveals convergent gene gain and loss associated with specialization onto cherry (Prunus avium). New Phytol 2018; 219:672-696. [PMID: 29726587 DOI: 10.1111/nph.15182] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/22/2018] [Indexed: 05/12/2023]
Abstract
Genome-wide analyses of the effector- and toxin-encoding genes were used to examine the phylogenetics and evolution of pathogenicity amongst diverse strains of Pseudomonas syringae causing bacterial canker of cherry (Prunus avium), including pathovars P. syringae pv morsprunorum (Psm) races 1 and 2, P. syringae pv syringae (Pss) and P. syringae pv avii. Phylogenetic analyses revealed Psm races and P. syringae pv avii clades were distinct and were each monophyletic, whereas cherry-pathogenic strains of Pss were interspersed amongst strains from other host species. A maximum likelihood approach was used to predict effectors associated with pathogenicity on cherry. Pss possesses a smaller repertoire of type III effectors but has more toxin biosynthesis clusters than Psm and P. syringae pv avii. Evolution of cherry pathogenicity was correlated with gain of genes such as hopAR1 and hopBB1 through putative phage transfer and horizontal transfer respectively. By contrast, loss of the avrPto/hopAB redundant effector group was observed in cherry-pathogenic clades. Ectopic expression of hopAB and hopC1 triggered the hypersensitive reaction in cherry leaves, confirming computational predictions. Cherry canker provides a fascinating example of convergent evolution of pathogenicity that is explained by the mix of effector and toxin repertoires acting on a common host.
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Affiliation(s)
- Michelle T Hulin
- NIAB EMR, New Road, East Malling, ME19 6BJ, UK
- School of Biological Sciences, University of Reading, Reading, RG6 6AJ, UK
| | | | - Joana G Vicente
- School of Life Sciences, Warwick Crop Centre, University of Warwick, Wellesbourne, CV35 9EF, UK
| | - Eric B Holub
- School of Life Sciences, Warwick Crop Centre, University of Warwick, Wellesbourne, CV35 9EF, UK
| | - Laura Baxter
- School of Life Sciences, Warwick Crop Centre, University of Warwick, Wellesbourne, CV35 9EF, UK
| | | | - John W Mansfield
- Faculty of Natural Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Robert W Jackson
- School of Biological Sciences, University of Reading, Reading, RG6 6AJ, UK
| | - Richard J Harrison
- NIAB EMR, New Road, East Malling, ME19 6BJ, UK
- School of Biological Sciences, University of Reading, Reading, RG6 6AJ, UK
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13
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Li B, Hulin MT, Brain P, Mansfield JW, Jackson RW, Harrison RJ. Rapid, automated detection of stem canker symptoms in woody perennials using artificial neural network analysis. Plant Methods 2015; 11:57. [PMID: 26705407 PMCID: PMC4690310 DOI: 10.1186/s13007-015-0100-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 12/09/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND Pseudomonas syringae can cause stem necrosis and canker in a wide range of woody species including cherry, plum, peach, horse chestnut and ash. The detection and quantification of lesion progression over time in woody tissues is a key trait for breeders to select upon for resistance. RESULTS In this study a general, rapid and reliable approach to lesion quantification using image recognition and an artificial neural network model was developed. This was applied to screen both the virulence of a range of P. syringae pathovars and the resistance of a set of cherry and plum accessions to bacterial canker. The method developed was more objective than scoring by eye and allowed the detection of putatively resistant plant material for further study. CONCLUSIONS Automated image analysis will facilitate rapid screening of material for resistance to bacterial and other phytopathogens, allowing more efficient selection and quantification of resistance responses.
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Affiliation(s)
- Bo Li
- />East Malling Research, New Road, East Malling, ME19 6BJ Kent, UK
| | - Michelle T. Hulin
- />East Malling Research, New Road, East Malling, ME19 6BJ Kent, UK
- />School of Biological Sciences, University of Reading, Reading, RG6 6AJ UK
| | - Philip Brain
- />East Malling Research, New Road, East Malling, ME19 6BJ Kent, UK
| | - John W. Mansfield
- />Faculty of Natural Sciences, Imperial College London, SW7 2AZ London, UK
| | - Robert W. Jackson
- />School of Biological Sciences, University of Reading, Reading, RG6 6AJ UK
| | - Richard J. Harrison
- />East Malling Research, New Road, East Malling, ME19 6BJ Kent, UK
- />School of Biological Sciences, University of Reading, Reading, RG6 6AJ UK
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