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Zhang W, Gundel PE, Jáuregui R, Card SD, Mace WJ, Johnson RD, Bastías DA. The growth promotion in endophyte symbiotic plants does not penalise the resistance to herbivores and bacterial microbiota. PLANT, CELL & ENVIRONMENT 2024; 47:2865-2878. [PMID: 38616528 DOI: 10.1111/pce.14912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/19/2024] [Accepted: 03/29/2024] [Indexed: 04/16/2024]
Abstract
A trade-off between growth and defence against biotic stresses is common in plants. Fungal endophytes of the genus Epichloë may relieve this trade-off in their host grasses since they can simultaneously induce plant growth and produce antiherbivore alkaloids that circumvent the need for host defence. The Epichloë ability to decouple the growth-defence trade-off was evaluated by subjecting ryegrass with and without Epichloë endophytes to an exogenous treatment with gibberellin (GA) followed by a challenge with Rhopalosiphum padi aphids. In agreement with the endophyte-mediated trade-off decoupling hypothesis, the GA-derived promotion of plant growth increased the susceptibility to aphids in endophyte-free plants but did not affect the insect resistance in endophyte-symbiotic plants. In line with the unaltered insect resistance, the GA treatment did not reduce the concentration of Epichloë-derived alkaloids. The Epichloë mycelial biomass was transiently increased by the GA treatment but at the expense of hyphal integrity. The response of the phyllosphere bacterial microbiota to both GA treatment and Epichloë was also evaluated. Only Epichloë, and not the GA treatment, altered the composition of the phyllosphere microbiota and the abundance of certain bacterial taxa. Our findings clearly demonstrate that Epichloë does indeed relieve the plant growth-defence trade-off.
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Affiliation(s)
- Wei Zhang
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Pedro E Gundel
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Ruy Jáuregui
- Animal Health Laboratory, Biosecurity New Zealand, Ministry for Primary Industries, Upper Hutt, New Zealand
| | - Stuart D Card
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Wade J Mace
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Richard D Johnson
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Daniel A Bastías
- AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
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Realini FM, Escobedo VM, Ueno AC, Bastías DA, Schardl CL, Biganzoli F, Gundel PE. Anti-herbivory defences delivered by Epichloë fungal endophytes: a quantitative review of alkaloid concentration variation among hosts and plant parts. ANNALS OF BOTANY 2024; 133:509-520. [PMID: 38320313 PMCID: PMC11037487 DOI: 10.1093/aob/mcae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND AND AIMS In the subfamily Poöideae (Poaceae), certain grass species possess anti-herbivore alkaloids synthesized by fungal endophytes that belong to the genus Epichloë (Clavicipitaceae). The protective role of these symbiotic endophytes can vary, depending on alkaloid concentrations within specific plant-endophyte associations and plant parts. METHODS We conducted a literature review to identify articles containing alkaloid concentration data for various plant parts in six important pasture species, Lolium arundinaceum, Lolium perenne, Lolium pratense, Lolium multiflorum|Lolium rigidum and Festuca rubra, associated with their common endophytes. We considered the alkaloids lolines (1-aminopyrrolizidines), peramine (pyrrolopyrazines), ergovaline (ergot alkaloids) and lolitrem B (indole-diterpenes). While all these alkaloids have shown bioactivity against insect herbivores, ergovaline and lolitrem B are harmful for mammals. KEY RESULTS Loline alkaloid levels were higher in the perennial grasses L. pratense and L. arundinaceum compared to the annual species L. multiflorum and L. rigidum, and higher in reproductive tissues than in vegetative structures. This is probably due to the greater biomass accumulation in perennial species that can result in higher endophyte mycelial biomass. Peramine concentrations were higher in L. perenne than in L. arundinaceum and not affected by plant part. This can be attributed to the high within-plant mobility of peramine. Ergovaline and lolitrem B, both hydrophobic compounds, were associated with plant parts where fungal mycelium is usually present, and their concentrations were higher in plant reproductive tissues. Only loline alkaloid data were sufficient for below-ground tissue analyses and concentrations were lower than in above-ground parts. CONCLUSIONS Our study provides a comprehensive synthesis of fungal alkaloid variation across host grasses and plant parts, essential for understanding the endophyte-conferred defence extent. The patterns can be understood by considering endophyte growth within the plant and alkaloid mobility. Our study identifies research gaps, including the limited documentation of alkaloid presence in roots and the need to investigate the influence of different environmental conditions.
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Affiliation(s)
- Florencia M Realini
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Departamento de Ecología, Genética y Evolución, Laboratorio de Citogenética y Evolución (LaCyE), Ciudad Autónoma de Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Ecología, Genética y Evolución (IEGEBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Víctor M Escobedo
- Instituto de Investigación Interdisciplinaria (I3), Universidad de Talca, Campus Talca, Chile
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Andrea C Ueno
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Instituto de Investigación Interdisciplinaria (I3), Universidad de Talca, Campus Talca, Chile
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
| | - Daniel A Bastías
- AgResearch Limited, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | | | - Fernando Biganzoli
- Departamento de Métodos Cuantitativos y Sistemas de Información, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pedro E Gundel
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca, Chile
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Passarge A, Demir F, Green K, Depotter JRL, Scott B, Huesgen PF, Doehlemann G, Misas Villamil JC. Host apoplastic cysteine protease activity is suppressed during the mutualistic association of Lolium perenne and Epichloë festucae. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3410-3426. [PMID: 33630999 DOI: 10.1093/jxb/erab088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/19/2021] [Indexed: 06/12/2023]
Abstract
Plants secrete various defence-related proteins into the apoplast, including proteases. Papain-like cysteine proteases (PLCPs) are central components of the plant immune system. To overcome plant immunity and successfully colonize their hosts, several plant pathogens secrete effector proteins inhibiting plant PLCPs. We hypothesized that not only pathogens, but also mutualistic microorganisms interfere with PLCP-meditated plant defences to maintain endophytic colonization with their hosts. Epichloë festucae forms mutualistic associations with cool season grasses and produces a range of secondary metabolites that protect the host against herbivores. In this study, we performed a genome-wide identification of Lolium perenne PLCPs, analysed their evolutionary relationship, and classified them into nine PLCP subfamilies. Using activity-based protein profiling, we identified four active PLCPs in the apoplast of L. perenne leaves that are inhibited during endophyte interactions. We characterized the L. perenne cystatin LpCys1 for its inhibitory capacity against ryegrass PLCPs. LpCys1 abundance is not altered during the mutualistic interaction and it mainly inhibits LpCP2. However, since the activity of other L. perenne PLCPs is not sensitive to LpCys1, we propose that additional inhibitors, likely of fungal origin, are involved in the suppression of apoplastic PLCPs during E. festucae infection.
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Affiliation(s)
- Andrea Passarge
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Fatih Demir
- Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Jülich, Germany
| | - Kimberly Green
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | | | - Barry Scott
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich, Jülich, Germany
- Cologne Excellence Cluster for Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Institute for Biochemistry, University of Cologne, Cologne, Germany
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Green KA, Berry D, Feussner K, Eaton CJ, Ram A, Mesarich CH, Solomon P, Feussner I, Scott B. Lolium perenne apoplast metabolomics for identification of novel metabolites produced by the symbiotic fungus Epichloë festucae. THE NEW PHYTOLOGIST 2020; 227:559-571. [PMID: 32155669 PMCID: PMC7317419 DOI: 10.1111/nph.16528] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 02/28/2020] [Indexed: 05/05/2023]
Abstract
Epichloë festucae is an endophytic fungus that forms a symbiotic association with Lolium perenne. Here we analysed how the metabolome of the ryegrass apoplast changed upon infection of this host with sexual and asexual isolates of E. festucae. A metabolite fingerprinting approach was used to analyse the metabolite composition of apoplastic wash fluid from uninfected and infected L. perenne. Metabolites enriched or depleted in one or both of these treatments were identified using a set of interactive tools. A genetic approach in combination with tandem MS was used to identify a novel product of a secondary metabolite gene cluster. Metabolites likely to be present in the apoplast were identified using MarVis in combination with the BioCyc and KEGG databases, and an in-house Epichloë metabolite database. We were able to identify the known endophyte-specific metabolites, peramine and epichloëcyclins, as well as a large number of unknown markers. To determine whether these methods can be applied to the identification of novel Epichloë-derived metabolites, we deleted a gene encoding a NRPS (lgsA) that is highly expressed in planta. Comparative MS analysis of apoplastic wash fluid from wild-type- vs mutant-infected plants identified a novel Leu/Ile glycoside metabolite present in the former.
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Affiliation(s)
- Kimberly A. Green
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Daniel Berry
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Kirstin Feussner
- Department of Plant BiochemistryAlbrecht von Haller Institute for Plant SciencesUniversity of GoettingenD‐37077GoettingenGermany
- Service Unit for Metabolomics and LipidomicsGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
| | - Carla J. Eaton
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
| | - Arvina Ram
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
| | - Carl H. Mesarich
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
- School of Agriculture and EnvironmentMassey UniversityPalmerston North4442New Zealand
| | - Peter Solomon
- Research School of BiologyAustralian National UniversityCanberraACT0200Australia
| | - Ivo Feussner
- Department of Plant BiochemistryAlbrecht von Haller Institute for Plant SciencesUniversity of GoettingenD‐37077GoettingenGermany
- Service Unit for Metabolomics and LipidomicsGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
- Department of Plant BiochemistryGoettingen Center for Molecular Biosciences (GZMB)University of GoettingenD‐37077GoettingenGermany
| | - Barry Scott
- School of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
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Green KA, Eaton CJ, Savoian MS, Scott B. A homologue of the fungal tetraspanin Pls1 is required for Epichloë festucae expressorium formation and establishment of a mutualistic interaction with Lolium perenne. MOLECULAR PLANT PATHOLOGY 2019; 20:961-975. [PMID: 31008572 PMCID: PMC6589725 DOI: 10.1111/mpp.12805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Epichloë festucae is an endophytic fungus that forms a mutualistic symbiotic association with the grass host Lolium perenne. Endophytic hyphae exit the host by an appressorium-like structure known as an expressorium. In plant-pathogenic fungi, the tetraspanin Pls1 and the NADPH oxidase component Nox2 are required for appressorium development. Previously we showed that the homologue of Nox2, NoxB, is required for E. festucae expressorium development and establishment of a mutualistic symbiotic interaction with the grass host. Here we used a reverse genetics approach to functionally characterize the role of the E. festucae homologue of Pls1, PlsA. The morphology and growth of ΔplsA in axenic culture was comparable to wild-type. The tiller length of plants infected with ΔplsA was significantly reduced. Hyphae of ΔplsA had a proliferative pattern of growth within the leaves of L. perenne with increased colonization of the intercellular spaces and the vascular bundles. The ΔplsA mutant was also defective in expressorium development although the phenotype was not as severe as for ΔnoxB, highlighting potentially distinct roles for PlsA and NoxB in signalling through the NoxB complex. Hyphae of ΔplsA proliferate below the cuticle surface but still occasionally form an expressorium-like structure that enables the mutant hyphae to exit the leaf to grow on the surface. These expressoria still form a septin ring-like structure at the point of cuticle exit as found in the wild-type strain. These results establish that E. festucae PlsA has an important, but distinct, role to NoxB in expressorium development and plant symbiosis.
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Affiliation(s)
- Kimberly A. Green
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Carla J. Eaton
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Matthew S. Savoian
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
| | - Barry Scott
- Institute of Fundamental SciencesMassey UniversityPalmerston NorthNew Zealand
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Complex epigenetic regulation of alkaloid biosynthesis and host interaction by heterochromatin protein I in a fungal endophyte-plant symbiosis. Fungal Genet Biol 2019; 125:71-83. [DOI: 10.1016/j.fgb.2019.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/29/2019] [Accepted: 02/03/2019] [Indexed: 01/10/2023]
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Liu J, Nagabhyru P, Schardl CL. Epichloë festucaeendophytic growth in florets, seeds, and seedlings of perennial ryegrass (Lolium perenne). Mycologia 2017; 109:691-700. [DOI: 10.1080/00275514.2017.1400305] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Jinge Liu
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0312
| | - Padmaja Nagabhyru
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0312
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8
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Becker M, Becker Y, Green K, Scott B. The endophytic symbiont Epichloë festucae establishes an epiphyllous net on the surface of Lolium perenne leaves by development of an expressorium, an appressorium-like leaf exit structure. THE NEW PHYTOLOGIST 2016; 211:240-54. [PMID: 26991322 PMCID: PMC5069595 DOI: 10.1111/nph.13931] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 02/07/2016] [Indexed: 05/16/2023]
Abstract
Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network. E. festucae also grows as an epiphyte, but the mechanism for leaf surface colonization is not known. Here we identify an appressorium-like structure, which we call an expressorium that allows endophytic hyphae to penetrate the cuticle from the inside of the leaf to establish an epiphytic hyphal net on the surface of the leaf. We used a combination of scanning electron, transmission electron and confocal laser scanning microscopy to characterize this novel fungal structure and determine the composition of the hyphal cell wall using aniline blue and wheat germ agglutinin labelled with Alexafluor-488. Expressoria differentiate immediately below the cuticle in the leaf blade and leaf sheath intercalary cell division zones where the hyphae grow by tip growth. Differentiation of this structure requires components of both the NoxA and NoxB NADPH oxidase complexes. Major remodelling of the hyphal cell wall occurs following exit from the leaf. These results establish that the symbiotic association of E. festucae with L. perenne involves an interconnected hyphal network of both endophytic and epiphytic hyphae.
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Affiliation(s)
- Matthias Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Yvonne Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Kimberly Green
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
| | - Barry Scott
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
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Tadych M, Bergen MS, White JF. Epichloë spp. associated with grasses: new insights on life cycles, dissemination and evolution. Mycologia 2014; 106:181-201. [PMID: 24877257 DOI: 10.3852/106.2.181] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epichloë species with their asexual states are specialized fungi associated with cool-season grasses. they grow endophytically in tissues of aerial parts of host plants to form systemic and mostly asymptomatic associations. Their life cycles may involve vertical transmission through host seeds and/or horizontal transmission from one plant to other plants of the same species through fungal propagules. Vertical transmission has been well studied, but comparatively little research has been done on horizontal dissemination. The goal of this review is to provide new insights on modes of dissemination of systemic grass endophytes. The review addresses recent progress in research on (i) the process of growth of Epichloë endophytes in the host plant tissues, (ii) the types and development of reproductive structures of the endophyte, (iii) the role of the reproductive structures in endophyte dissemination and host plant infection processes and (iv) some ecological and evolutionary implications of their modes of dissemination. Research in the Epichloë grass endophytes has accelerated in the past 25 y and has demonstrated the enormous complexity in endophyte-grass symbioses. There still remain large gaps in our understanding of the role and functions of these fungi in agricultural systems and understanding the functions, ecology and evolution of these endophytes in natural grass populations.
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Chujo T, Scott B. Histone H3K9 and H3K27 methylation regulates fungal alkaloid biosynthesis in a fungal endophyte-plant symbiosis. Mol Microbiol 2014; 92:413-34. [PMID: 24571357 DOI: 10.1111/mmi.12567] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 12/17/2022]
Abstract
Epichloё festucae is a filamentous fungus that forms a mutually beneficial symbiotic association with Lolium perenne. This endophyte synthesizes bioprotective lolitrems (ltm) and ergot alkaloids (eas) in planta but the mechanisms regulating expression of the corresponding subtelomeric gene clusters are not known. We show here that the status of histone H3 lysine 9 and lysine 27 trimethylation (H3K9me3/H3K27me3) at these alkaloid gene loci are critical determinants of transcriptional activity. Using ChIP-qPCR we found that levels of H3K9me3 and H3K27me3 were reduced at these loci in plant infected tissue compared to axenic culture. Deletion of E. festucae genes encoding the H3K9- (ClrD) or H3K27- (EzhB) methyltransferases led to derepression of ltm and eas gene expression under non-symbiotic culture conditions and a further enhancement of expression in the double deletion mutant. These changes in gene expression were matched by corresponding reductions in H3K9me3 and H3K27me3 marks. Both methyltransferases are also important for the symbiotic interaction between E. festucae and L. perenne. Our results show that the state of H3K9 and H3K27 trimethylation of E. festucae chromatin is an important regulatory layer controlling symbiosis-specific expression of alkaloid bioprotective metabolites and the ability of this symbiont to form a mutualistic interaction with its host.
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Affiliation(s)
- Tetsuya Chujo
- Institute of Fundamental Sciences, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand
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11
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di Menna ME, Finch SC, Popay AJ, Smith BL. A review of the Neotyphodium lolii / Lolium perenne symbiosis and its associated effects on animal and plant health, with particular emphasis on ryegrass staggers. N Z Vet J 2012; 60:315-28. [PMID: 22913513 DOI: 10.1080/00480169.2012.697429] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Ryegrass staggers is a seasonal mycotoxicosis of grazing livestock characterised by tremors, in coordination and a staggering gait almost unaccompanied by physical lesions. Deaths occur only as a consequence of accident or starvation. Outbreaks, in summer and autumn, occur only on pasture in which endophyte (Neotyphodium lolii)-infected perennial ryegrass (Lolium perenne) predominates and usually on which animals are grazed intensively. Animals recover when moved to a different type of grazing or after rain has promoted pasture growth. The disease was recognised for 80 years before its cause was discovered as a consequence of a grazing trial of sheep on three ryegrass cultivars which happened to have three different levels of endophyte infection. The endophyte was first formally described as Acremonium loliae, later corrected to Acremonium lolii, and was finally placed in the genus Neotyphodium. It produces a number of secondary metabolites of which lolitrem B is the principal one causing ryegrass staggers symptoms. Ergopeptides are also produced which cause heat stress and lack of productivity. N. lolii is symptomless in the plant, seed borne and grows intercellularly in the aerial parts, mainly in reproductive tillers and leaf sheaths but sparsely in leaf blades. It dies in stored seed and infection rates of different ryegrass cultivars have depended on seed storage times during their production. In addition, N. Lolii produces insect feeding deterrents, among them peramine, which protects infected plants from pest predation. Because of this, control of ryegrass staggers by elimination of endophyte-infected ryegrass is not feasible in areas in which insect predation is a serious pasture problem. However, N. lolii strains vary in the secondary metabolites they produce allowing the selection of strains that produce desirable metabolites. By inoculating such strains into uninfected ryegrass plants it is possible to produce cultivars which do not cause ryegrass staggers but resist insect predation. This review aims to provide a comprehensive summary of the current understanding of the N. lolii / L. perenne symbiosis, the toxins it is known to produce, their effects on animals and plants and the strategies used to control their ill effects while maximising their beneficial ones.
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Affiliation(s)
- M E di Menna
- AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, 3240, New Zealand.
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12
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Scott B, Becker Y, Becker M, Cartwright G. Morphogenesis, Growth, and Development of the Grass Symbiont Epichlöe festucae. TOPICS IN CURRENT GENETICS 2012. [DOI: 10.1007/978-3-642-22916-9_12] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Dombrowski JE, Baldwin JC, Alderman SC, Martin RC. Transformation of Epichloë typhina by electroporation of conidia. BMC Res Notes 2011; 4:46. [PMID: 21375770 PMCID: PMC3058031 DOI: 10.1186/1756-0500-4-46] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 03/05/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Choke, caused by the endophytic fungus Epichloë typhina, is an important disease affecting orchardgrass (Dactylis glomerata L.) seed production in the Willamette Valley. Little is known concerning the conditions necessary for successful infection of orchardgrass by E. typhina. Detection of E. typhina in plants early in the disease cycle can be difficult due to the sparse distribution of hyphae in the plant. Therefore, a sensitive method to detect fungal infection in plants would provide an invaluable tool for elucidating the conditions for establishment of infection in orchardgrass. Utilization of a marker gene, such as the green fluorescent protein (GFP), transformed into Epichloë will facilitate characterization of the initial stages of infection and establishment of the fungus in plants. FINDINGS We have developed a rapid, efficient, and reproducible transformation method using electroporation of germinating Epichloë conidia isolated from infected plants. CONCLUSIONS The GFP labelled E. typhina provides a valuable molecular tool to researchers studying conditions and mechanisms involved in the establishment of choke disease in orchardgrass.
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Affiliation(s)
- James E Dombrowski
- USDA-ARS National Forage Seed Production Research Center, 3450 S.W. Campus Way, Corvallis, OR 97331 USA
| | - James C Baldwin
- Applied Technology Center, 2484 Gillingham Drive, B-175W Brooks City-Base, TX 78235 USA
| | - Steve C Alderman
- USDA-ARS National Forage Seed Production Research Center, 3450 S.W. Campus Way, Corvallis, OR 97331 USA
| | - Ruth C Martin
- USDA-ARS National Forage Seed Production Research Center, 3450 S.W. Campus Way, Corvallis, OR 97331 USA
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van der Does HC, Duyvesteijn RG, Goltstein PM, van Schie CC, Manders EM, Cornelissen BJ, Rep M. Expression of effector gene SIX1 of Fusarium oxysporum requires living plant cells. Fungal Genet Biol 2008; 45:1257-64. [DOI: 10.1016/j.fgb.2008.06.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 06/06/2008] [Accepted: 06/10/2008] [Indexed: 10/21/2022]
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