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Marcet-Houben M, Cruz F, Gómez-Garrido J, Alioto TS, Nunez-Rodriguez JC, Mesanza N, Gut M, Iturritxa E, Gabaldon T. Genomics of the expanding pine pathogen Lecanosticta acicola reveals patterns of ongoing genetic admixture. mSystems 2024; 9:e0092823. [PMID: 38364101 PMCID: PMC10949461 DOI: 10.1128/msystems.00928-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 01/09/2024] [Indexed: 02/18/2024] Open
Abstract
Lecanosticta acicola is the causal agent for brown spot needle blight that affects pine trees across the northern hemisphere. Based on marker genes and microsatellite data, two distinct lineages have been identified that were introduced into Europe on two separate occasions. Despite their overall distinct geographic distribution, they have been found to coexist in regions of northern Spain and France. Here, we present the first genome-wide study of Lecanosticta acicola, including assembly of the reference genome and a population genomics analysis of 70 natural isolates from northern Spain. We show that most of the isolates belong to the southern lineage but show signs of introgression with northern lineage isolates, indicating mating between the two lineages. We also identify phenotypic differences between the two lineages based on the activity profiles of 20 enzymes, with introgressed strains being more phenotypically similar to members of the southern lineage. In conclusion, we show undergoing genetic admixture between the two main lineages of L. acicola in a region of recent expansion. IMPORTANCE Lecanosticta acicola is a fungal pathogen causing severe defoliation, growth reduction, and even death in more than 70 conifer species. Despite the increasing incidence of this species, little is known about its population dynamics. Two divergent lineages have been described that have now been found together in regions of France and Spain, but it is unknown how these mixed populations evolve. Here we present the first reference genome for this important plant pathogenic fungi and use it to study the population genomics of 70 isolates from an affected forest in the north of Spain. We find signs of introgression between the two main lineages, indicating that active mating is occurring in this region which could propitiate the appearance of novel traits in this species. We also study the phenotypic differences across this population based on enzymatic activities on 20 compounds.
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Affiliation(s)
- Marina Marcet-Houben
- Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica En Red de Enfermedades Infecciosas (CIBERINFEC), Barcelona, Spain
| | - Fernando Cruz
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Jéssica Gómez-Garrido
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Tyler S. Alioto
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Juan Carlos Nunez-Rodriguez
- Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Nebai Mesanza
- Instituto Vasco de Investigación y Desarrollo Agrario (BRTA), Arkaute, Araba, Spain
| | - Marta Gut
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Eugenia Iturritxa
- Instituto Vasco de Investigación y Desarrollo Agrario (BRTA), Arkaute, Araba, Spain
| | - Toni Gabaldon
- Barcelona Supercomputing Centre (BSC-CNS), Barcelona, Spain
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica En Red de Enfermedades Infecciosas (CIBERINFEC), Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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Mesarich CH, Barnes I, Bradley EL, de la Rosa S, de Wit PJGM, Guo Y, Griffiths SA, Hamelin RC, Joosten MHAJ, Lu M, McCarthy HM, Schol CR, Stergiopoulos I, Tarallo M, Zaccaron AZ, Bradshaw RE. Beyond the genomes of Fulvia fulva (syn. Cladosporium fulvum) and Dothistroma septosporum: New insights into how these fungal pathogens interact with their host plants. MOLECULAR PLANT PATHOLOGY 2023; 24:474-494. [PMID: 36790136 PMCID: PMC10098069 DOI: 10.1111/mpp.13309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 05/03/2023]
Abstract
Fulvia fulva and Dothistroma septosporum are closely related apoplastic pathogens with similar lifestyles but different hosts: F. fulva is a pathogen of tomato, whilst D. septosporum is a pathogen of pine trees. In 2012, the first genome sequences of these pathogens were published, with F. fulva and D. septosporum having highly fragmented and near-complete assemblies, respectively. Since then, significant advances have been made in unravelling their genome architectures. For instance, the genome of F. fulva has now been assembled into 14 chromosomes, 13 of which have synteny with the 14 chromosomes of D. septosporum, suggesting these pathogens are even more closely related than originally thought. Considerable advances have also been made in the identification and functional characterization of virulence factors (e.g., effector proteins and secondary metabolites) from these pathogens, thereby providing new insights into how they promote host colonization or activate plant defence responses. For example, it has now been established that effector proteins from both F. fulva and D. septosporum interact with cell-surface immune receptors and co-receptors to activate the plant immune system. Progress has also been made in understanding how F. fulva and D. septosporum have evolved with their host plants, whilst intensive research into pandemics of Dothistroma needle blight in the Northern Hemisphere has shed light on the origins, migration, and genetic diversity of the global D. septosporum population. In this review, we specifically summarize advances made in our understanding of the F. fulva-tomato and D. septosporum-pine pathosystems over the last 10 years.
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Affiliation(s)
- Carl H. Mesarich
- Laboratory of Molecular Plant Pathology, School of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
- Bioprotection AotearoaMassey UniversityPalmerston NorthNew Zealand
| | - Irene Barnes
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology InstituteUniversity of PretoriaPretoriaSouth Africa
| | - Ellie L. Bradley
- Laboratory of Molecular Plant Pathology, School of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
| | - Silvia de la Rosa
- Laboratory of Molecular Plant Pathology, School of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
| | | | - Yanan Guo
- Bioprotection AotearoaMassey UniversityPalmerston NorthNew Zealand
- Laboratory of Molecular Plant Pathology, School of Natural SciencesMassey UniversityPalmerston NorthNew Zealand
| | | | - Richard C. Hamelin
- Department of Forest and Conservation SciencesUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Institut de Biologie Intégrative et des SystèmesUniversité LavalQuébec CityQuébecCanada
| | | | - Mengmeng Lu
- Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
| | - Hannah M. McCarthy
- Laboratory of Molecular Plant Pathology, School of Natural SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Christiaan R. Schol
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
- Plant BreedingWageningen University & ResearchWageningenNetherlands
| | | | - Mariana Tarallo
- Laboratory of Molecular Plant Pathology, School of Natural SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Alex Z. Zaccaron
- Department of Plant PathologyUniversity of California DavisDavisCaliforniaUSA
| | - Rosie E. Bradshaw
- Bioprotection AotearoaMassey UniversityPalmerston NorthNew Zealand
- Laboratory of Molecular Plant Pathology, School of Natural SciencesMassey UniversityPalmerston NorthNew Zealand
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McCarthy HM, Tarallo M, Mesarich CH, McDougal RL, Bradshaw RE. Targeted Gene Mutations in the Forest Pathogen Dothistroma septosporum Using CRISPR/Cas9. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11081016. [PMID: 35448744 PMCID: PMC9025729 DOI: 10.3390/plants11081016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 05/19/2023]
Abstract
Dothistroma needle blight, caused by Dothistroma septosporum, has increased in incidence and severity over the last few decades and is now one of the most important global diseases of pines. Disease resistance breeding could be accelerated by knowledge of pathogen virulence factors and their host targets. However, this is hindered due to inefficient targeted gene disruption in D. septosporum, which is required for virulence gene characterisation. Here we report the first successful application of CRISPR/Cas9 gene editing to a Dothideomycete forest pathogen, D. septosporum. Disruption of the dothistromin pathway regulator gene AflR, with a known phenotype, was performed using nonhomologous end-joining repair with an efficiency of > 90%. Transformants with a range of disruption mutations in AflR were produced. Disruption of Ds74283, a D. septosporum gene encoding a secreted cell death elicitor, was also achieved using CRISPR/Cas9, by using a specific donor DNA repair template to aid selection where the phenotype was unknown. In this case, 100% of screened transformants were identified as disruptants. In establishing CRISPR/Cas9 as a tool for gene editing in D. septosporum, our research could fast track the functional characterisation of candidate virulence factors in D. septosporum and helps set the foundation for development of this technology in other forest pathogens.
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Affiliation(s)
- Hannah M. McCarthy
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
- Correspondence:
| | - Mariana Tarallo
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
| | - Carl H. Mesarich
- BioProtection Aotearoa, School of Agriculture and Environment, Massey University, Palmerston North 4472, New Zealand;
| | - Rebecca L. McDougal
- Scion, New Zealand Forest Research Institute Ltd., Rotorua 3010, New Zealand;
| | - Rosie E. Bradshaw
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
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Guo Y, Dupont P, Mesarich CH, Yang B, McDougal RL, Panda P, Dijkwel P, Studholme DJ, Sambles C, Win J, Wang Y, Williams NM, Bradshaw RE. Functional analysis of RXLR effectors from the New Zealand kauri dieback pathogen Phytophthora agathidicida. MOLECULAR PLANT PATHOLOGY 2020; 21:1131-1148. [PMID: 32638523 PMCID: PMC7411639 DOI: 10.1111/mpp.12967] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/25/2020] [Accepted: 06/01/2020] [Indexed: 05/08/2023]
Abstract
New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms. From the P. agathidicida genome, we defined and analysed a set of RXLR effectors, a class of proteins that typically have important roles in suppressing or activating the plant immune system. RXLRs were screened for their ability to activate or suppress the Nicotiana plant immune system using Agrobacterium tumefaciens transient transformation assays. Nine P. agathidicida RXLRs triggered cell death or suppressed plant immunity in Nicotiana, of which three were expressed in kauri. For the most highly expressed, P. agathidicida (Pa) RXLR24, candidate cognate immune receptors associated with cell death were identified in Nicotiana benthamiana using RNA silencing-based approaches. Our results show that RXLRs of a pathogen of gymnosperms can interact with the immune system of an angiosperm species. This study provides an important foundation for studying the molecular basis of plant-pathogen interactions in gymnosperm forest trees, including kauri.
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Affiliation(s)
- Yanan Guo
- Bio‐Protection Research CentreSchool of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | | | - Carl H. Mesarich
- Bio‐Protection Research CentreSchool of Agriculture and EnvironmentMassey UniversityPalmerston NorthNew Zealand
| | - Bo Yang
- Department of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | | | - Preeti Panda
- Scion (New Zealand Forest Research Institute Ltd.)RotoruaNew Zealand
- The New Zealand Institute for Plant and Food ResearchAucklandNew Zealand
| | - Paul Dijkwel
- Bio‐Protection Research CentreSchool of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | | | | | - Joe Win
- The Sainsbury LaboratoryUniversity of East AngliaNorwichUK
| | - Yuanchao Wang
- Department of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Nari M. Williams
- Scion (New Zealand Forest Research Institute Ltd.)RotoruaNew Zealand
- The New Zealand Institute for Plant and Food ResearchAucklandNew Zealand
| | - Rosie E. Bradshaw
- Bio‐Protection Research CentreSchool of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
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Guo Y, Hunziker L, Mesarich CH, Chettri P, Dupont PY, Ganley RJ, McDougal RL, Barnes I, Bradshaw RE. DsEcp2-1 is a polymorphic effector that restricts growth of Dothistroma septosporum in pine. Fungal Genet Biol 2020; 135:103300. [PMID: 31730909 DOI: 10.1016/j.fgb.2019.103300] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/05/2019] [Accepted: 11/05/2019] [Indexed: 12/22/2022]
Abstract
The detrimental effect of fungal pathogens on forest trees is an increasingly important problem that has implications for the health of our planet. Despite this, the study of molecular plant-microbe interactions in forest trees is in its infancy, and very little is known about the roles of effector molecules from forest pathogens. Dothistroma septosporum causes a devastating needle blight disease of pines, and intriguingly, is closely related to Cladosporium fulvum, a tomato pathogen in which pioneering effector biology studies have been carried out. Here, we studied D. septosporum effectors that are shared with C. fulvum, by comparing gene sequences from global isolates of D. septosporum and assessing effector function in both host and non-host plants. Many of the effectors were predicted to be non-functional in D. septosporum due to their pseudogenization or low expression in planta, suggesting adaptation to lifestyle and host. Effector sequences were polymorphic among a global collection of D. septosporum isolates, but there was no evidence for positive selection. The DsEcp2-1 effector elicited cell death in the non-host plant Nicotiana tabacum, whilst D. septosporum DsEcp2-1 mutants showed increased colonization of pine needles. Together these results suggest that DsEcp2-1 might be recognized by an immune receptor in both angiosperm and gymnosperm plants. This work may lead to the identification of plant targets for DsEcp2-1 that will provide much needed information on the molecular basis of gymnosperm-pathogen interactions in forests, and may also lead to novel methods of disease control.
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Affiliation(s)
- Yanan Guo
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand.
| | - Lukas Hunziker
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand
| | - Carl H Mesarich
- Bio-Protection Research Centre, School of Agriculture and Environment, Massey University, Palmerston North 4474, New Zealand
| | - Pranav Chettri
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
| | - Pierre-Yves Dupont
- Institute of Environmental Science and Research, Christchurch 8041, New Zealand
| | - Rebecca J Ganley
- The New Zealand Institute for Plant & Food Research Limited, Te Puke, New Zealand
| | - Rebecca L McDougal
- Scion, New Zealand Forest Research Institute Ltd, Rotorua 3010, New Zealand
| | - Irene Barnes
- Department of Genetics, Biochemistry and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Rosie E Bradshaw
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand
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