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Chacón-Fuentes M, Martínez-Cisterna D, Lizama M, Asencio-Cancino V, Matamala I, Bardehle L. A Countermeasure Strategy against Peramine Developed by Chilesia rudis in the Endophyte-Ryegrass-Herbivore Model. J Fungi (Basel) 2024; 10:512. [PMID: 39194838 DOI: 10.3390/jof10080512] [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: 06/20/2024] [Revised: 07/14/2024] [Accepted: 07/18/2024] [Indexed: 08/29/2024] Open
Abstract
Exploitation of the symbiotic relationship between endophytic fungi and ryegrass is a crucial technique for reducing the incidence of insect pests. This is primarily due to the production of alkaloids, such as peramine, by the fungi. This alkaloid has been reported as both a deterrent and toxic to a variety of insects. However, insects have developed various strategies to counteract plant defenses. One of the most studied methods is their ability to sequester toxic compounds from plants. In this study, we examined the feeding preferences and adaptation to peramine in Chilesia rudis, a native Chilean larva. Using a no-choice assay, we assessed larval feeding preferences and mass gain on seven experimental lines and two commercial cultivars of endophyte-infected and non-infected ryegrass. Pupal development time and adult performance were evaluated post-assay. Additionally, we measured peramine content in larval carcasses, feces, and ryegrass leaves. Jumbo was the most preferred cultivar with 32 mm2 of leaf tissues consumed. The longest pupal development time was observed in L161 and ALTO AR1, both at 28 days. Wing length in adults was greatest in the Jumbo and L163 cultivars, measuring 1.25 cm and 1.32 cm, respectively. Peramine concentrations were detected in the bodies of C. rudis. In conclusion, this larva can adapt to endophyte-infected ryegrass and develop counter-adaptation mechanisms to mitigate the effects of peramine.
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Affiliation(s)
- Manuel Chacón-Fuentes
- Agriaquaculture Nutritional Genomic Center, CGNA, Las Heras 350, Temuco 4780000, Chile
| | - Daniel Martínez-Cisterna
- Centro de Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco 4811230, Chile
- Programa de Doctorado en Ciencias de Recursos Naturales, Universidad de La Frontera, s/n, P.O. Box 58-D, Temuco 4780000, Chile
| | - Marcelo Lizama
- Programa de Doctorado en Ciencias Agroalimentarias y Medioambiente, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco 4811230, Chile
- Escuela de Universidad de Valladolid Doctorado (ESDUVa), Departamento Producción Vegetal y Recursos Forestales, Escuela Técnica Superior de Ingenierías Agrarias, Campus "La Yutera", Avda. de Madrid, 50, 34004 Palencia, Spain
| | - Valeria Asencio-Cancino
- Carrera de Ingenieria en Recursos Naturales, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Temuco 4811230, Chile
| | - Ignacio Matamala
- Programa de Doctorado en Ciencias Agroalimentarias y Medioambiente, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco 4811230, Chile
- Departamento de Producción Agropecuaria, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Temuco 4811230, Chile
| | - Leonardo Bardehle
- Centro de Investigación Biotecnológica Aplicada al Medio Ambiente (CIBAMA), Universidad de La Frontera, Av. Francisco Salazar 01145, Casilla 54-D, Temuco 4811230, Chile
- Departamento de Producción Agropecuaria, Facultad de Ciencias Agropecuarias y Medioambiente, Universidad de La Frontera, Temuco 4811230, Chile
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Scott K, Konkel Z, Gluck-Thaler E, Valero David GE, Simmt CF, Grootmyers D, Chaverri P, Slot J. Endophyte genomes support greater metabolic gene cluster diversity compared with non-endophytes in Trichoderma. PLoS One 2023; 18:e0289280. [PMID: 38127903 PMCID: PMC10735191 DOI: 10.1371/journal.pone.0289280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 07/14/2023] [Indexed: 12/23/2023] Open
Abstract
Trichoderma is a cosmopolitan genus with diverse lifestyles and nutritional modes, including mycotrophy, saprophytism, and endophytism. Previous research has reported greater metabolic gene repertoires in endophytic fungal species compared to closely-related non-endophytes. However, the extent of this ecological trend and its underlying mechanisms are unclear. Some endophytic fungi may also be mycotrophs and have one or more mycoparasitism mechanisms. Mycotrophic endophytes are prominent in certain genera like Trichoderma, therefore, the mechanisms that enable these fungi to colonize both living plants and fungi may be the result of expanded metabolic gene repertoires. Our objective was to determine what, if any, genomic features are overrepresented in endophytic fungi genomes in order to undercover the genomic underpinning of the fungal endophytic lifestyle. Here we compared metabolic gene cluster and mycoparasitism gene diversity across a dataset of thirty-eight Trichoderma genomes representing the full breadth of environmental Trichoderma's diverse lifestyles and nutritional modes. We generated four new Trichoderma endophyticum genomes to improve the sampling of endophytic isolates from this genus. As predicted, endophytic Trichoderma genomes contained, on average, more total biosynthetic and degradative gene clusters than non-endophytic isolates, suggesting that the ability to create/modify a diversity of metabolites potential is beneficial or necessary to the endophytic fungi. Still, once the phylogenetic signal was taken in consideration, no particular class of metabolic gene cluster was independently associated with the Trichoderma endophytic lifestyle. Several mycoparasitism genes, but no chitinase genes, were associated with endophytic Trichoderma genomes. Most genomic differences between Trichoderma lifestyles and nutritional modes are difficult to disentangle from phylogenetic divergences among species, suggesting that Trichoderma genomes maybe particularly well-equipped for lifestyle plasticity. We also consider the role of endophytism in diversifying secondary metabolism after identifying the horizontal transfer of the ergot alkaloid gene cluster to Trichoderma.
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Affiliation(s)
- Kelsey Scott
- Department of Plant Pathology, The Ohio State University, Columbus, OH, United States of America
| | - Zachary Konkel
- Department of Plant Pathology, The Ohio State University, Columbus, OH, United States of America
- Center for Applied Plant Sciences, The Ohio State University, Columbus, OH, United States of America
| | - Emile Gluck-Thaler
- Laboratory of Evolutionary Genetics, University of Neuchâtel, Neuchâtel, Switzerland
| | | | - Coralie Farinas Simmt
- Department of Plant Pathology, The Ohio State University, Columbus, OH, United States of America
| | - Django Grootmyers
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, United States of America
| | - Priscila Chaverri
- Department of Natural Sciences, Bowie State University, Bowie, MD, United States of America
- School of Biology and Natural Products Research Center (CIPRONA), University of Costa Rica, San José, Costa Rica
| | - Jason Slot
- Department of Plant Pathology, The Ohio State University, Columbus, OH, United States of America
- Center for Psychedelic Drug Research and Education, The Ohio State University, Columbus, OH, United States of America
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Deng Y, Yu X, Yin J, Chen L, Zhao N, Gao Y, Ren A. Epichloë Endophyte Enhanced Insect Resistance of Host Grass Leymus Chinensis by Affecting Volatile Organic Compound Emissions. J Chem Ecol 2023:10.1007/s10886-023-01459-6. [PMID: 37917413 DOI: 10.1007/s10886-023-01459-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/03/2023] [Accepted: 10/05/2023] [Indexed: 11/04/2023]
Abstract
In plant-herbivore interactions, plant volatile organic compounds (VOCs) play an important role in anti-herbivore defense. Grasses and Epichloë endophytes often form defensive mutualistic symbioses. Most Epichloë species produce alkaloids to protect hosts from herbivores, but there is no strong evidence that endophytes can affect the insect resistance of their hosts by altering VOC emissions. In this study, a native dominant grass, sheepgrass (Leymus chinensis), and its herbivore, oriental migratory locust (Locusta migratoria), were used as experimental materials. We studied the effect of endophyte-associated VOC emissions on the insect resistance of L. chinensis. The results showed that endophyte infection enhanced insect resistance of the host, and locusts preferred the odor of endophyte-free (EF) leaves to that of endophyte-infected (EI) leaves. We determined the VOC profile of L. chinensis using gas chromatography-mass spectrometry (GC-MS), and found that endophyte infection decreased the pentadecane (an alkane) emission from uneaten plants, and increased the nonanal (an aldehyde) emission from eaten plants. The olfactory response experiment showed that locusts were attracted by high concentration of pentadecane, while repelled by high concentration of nonanal, indicating that Epichloë endophytes may increase locust resistance of L. chinensis by decreasing pentadecane while increasing nonanal emission. Our results suggest that endophytes can induce VOC-mediated defense in hosts in addition to producing alkaloids, contributing to a better understanding the endophyte-plant-herbivore interactions.
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Affiliation(s)
- Yongkang Deng
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xinhe Yu
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jiaqi Yin
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Lei Chen
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Nianxi Zhao
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Yubao Gao
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Anzhi Ren
- College of Life Sciences, Nankai University, Tianjin, 300071, China.
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Leuchtmann A, Schardl CL. Genetic Diversity of Epichloë Endophytes Associated with Brachypodium and Calamagrostis Host Grass Genera including Two New Species. J Fungi (Basel) 2022; 8:jof8101086. [PMID: 36294651 PMCID: PMC9605649 DOI: 10.3390/jof8101086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022] Open
Abstract
Fungi of genus Epichloë (Ascomycota, Clavicipitaceae) are common endophytic symbionts of Poaceae, including wild and agronomically important cool-season grass species (subfam. Poöideae). Here, we examined the genetic diversity of Epichloë from three European species of Brachypodium (B. sylvaticum, B. pinnatum and B. phoenicoides) and three species of Calamagrostis (C. arundinacea, C. purpurea and C. villosa), using DNA sequences of tubB and tefA genes. In addition, microsatellite markers were obtained from a larger set of isolates from B. sylvaticum sampled across Europe. Based on phylogenetic analyses the isolates from Brachypodium hosts were placed in three different subclades within the Epichloë typhina complex (ETC) but did not strictly group according to host grass species, suggesting that the host does not always select for particular endophyte genotypes. Analysis of microsatellite markers confirmed the presence of genetically distinct lineages of Epichloësylvatica on B. sylvaticum, which appeared to be tied to different modes of reproduction (sexual or asexual). Among isolates from Calamagrostis hosts, two subclades were detected which were placed outside ETC. These endophyte lineages are recognized as distinct species for which we propose the names E. calamagrostidis Leuchtm. & Schardl, sp. nov. and E. ftanensis Leuchtm. & A.D. Treindl, sp. nov. This study extends knowledge of the phylogeny and evolutionary diversification of Epichloë endophytes that are symbionts of wild Brachypodium and Calamagrostis host grasses.
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Affiliation(s)
- Adrian Leuchtmann
- Institute of Integrative Biology, ETH Zürich, CH-8092 Zürich, Switzerland
- Correspondence:
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Comparative Research on Metabolites of Different Species of Epichloë Endophytes and Their Host Achnatherum sibiricum. J Fungi (Basel) 2022; 8:jof8060619. [PMID: 35736102 PMCID: PMC9225340 DOI: 10.3390/jof8060619] [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: 04/13/2022] [Revised: 05/01/2022] [Accepted: 05/10/2022] [Indexed: 02/01/2023] Open
Abstract
Achnatherum sibiricum can be infected by two species of fungal endophytes, Epichloë gansuensis (Eg) and Epichloë sibirica (Es). In this study, the metabolites of Eg, Es, and their infected plants were studied by GC−MS analysis. The results showed that the metabolic profiles of Eg and Es were similar in general, and only six differential metabolites were detected. The direct effect of endophyte infection on the metabolites in A. sibiricum was that endophyte-infected plants could produce mannitol, which was not present in uninfected plants. Epichloë infection indirectly caused an increase in the soluble sugars in A. sibiricum related to growth and metabolites related to the defense against pathogens and herbivores, such as α-tocopherol, α-linolenic acid and aromatic amino acids. Epichloë infection could regulate galactose metabolism, starch and sucrose metabolism, tyrosine metabolism and phenylalanine metabolism of host grass. In addition, there was a significant positive correlation in the metabolite contents between the endophyte and the host.
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Fernando K, Reddy P, Guthridge KM, Spangenberg GC, Rochfort SJ. A Metabolomic Study of Epichloë Endophytes for Screening Antifungal Metabolites. Metabolites 2022; 12:metabo12010037. [PMID: 35050159 PMCID: PMC8781816 DOI: 10.3390/metabo12010037] [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: 11/28/2021] [Revised: 12/23/2021] [Accepted: 12/29/2021] [Indexed: 11/16/2022] Open
Abstract
Epichloë endophytes, fungal endosymbionts of Pooidae grasses, are commonly utilized in forage and turf industries because they produce beneficial metabolites that enhance resistance against environmental stressors such as insect feeding and disease caused by phytopathogen infection. In pastoral agriculture, phytopathogenic diseases impact both pasture quality and animal production. Recently, bioactive endophyte strains have been reported to secrete compounds that significantly inhibit the growth of phytopathogenic fungi in vitro. A screen of previously described Epichloë-produced antifeedant and toxic alkaloids determined that the antifungal bioactivity observed is not due to the production of these known metabolites, and so there is a need for methods to identify new bioactive metabolites. The process described here is applicable more generally for the identification of antifungals in new endophytes. This study aims to characterize the fungicidal potential of novel, ‘animal friendly’ Epichloë endophyte strains NEA12 and NEA23 that exhibit strong antifungal activity using an in vitro assay. Bioassay-guided fractionation, followed by metabolite analysis, identified 61 metabolites that, either singly or in combination, are responsible for the observed bioactivity. Analysis of the perennial ryegrass-endophyte symbiota confirmed that NEA12 and NEA23 produce the prospective antifungal metabolites in symbiotic association and thus are candidates for compounds that promote disease resistance in planta. The “known unknown” suite of antifungal metabolites identified in this study are potential biomarkers for the selection of strains that enhance pasture and turf production through better disease control.
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Affiliation(s)
- Krishni Fernando
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Priyanka Reddy
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
| | - Kathryn M. Guthridge
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
| | - German C. Spangenberg
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Simone J. Rochfort
- AgriBio, Centre for AgriBioscience, Agriculture Victoria, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (K.M.G.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
- Correspondence: ; Tel.: +61-390327110
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Fernando K, Reddy P, Spangenberg GC, Rochfort SJ, Guthridge KM. Metabolic Potential of Epichloë Endophytes for Host Grass Fungal Disease Resistance. Microorganisms 2021; 10:64. [PMID: 35056512 PMCID: PMC8781568 DOI: 10.3390/microorganisms10010064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 12/27/2022] Open
Abstract
Asexual species of the genus Epichloë (Clavicipitaceae, Ascomycota) form endosymbiotic associations with Pooidae grasses. This association is important both ecologically and to the pasture and turf industries, as the endophytic fungi confer a multitude of benefits to their host plant that improve competitive ability and performance such as growth promotion, abiotic stress tolerance, pest deterrence and increased host disease resistance. Biotic stress tolerance conferred by the production of bioprotective metabolites has a critical role in an industry context. While the known antimammalian and insecticidal toxins are well characterized due to their impact on livestock welfare, antimicrobial metabolites are less studied. Both pasture and turf grasses are challenged by many phytopathogenic diseases that result in significant economic losses and impact livestock health. Further investigations of Epichloë endophytes as natural biocontrol agents can be conducted on strains that are safe for animals. With the additional benefits of possessing host disease resistance, these strains would increase their commercial importance. Field reports have indicated that pasture grasses associated with Epichloë endophytes are superior in resisting fungal pathogens. However, only a few antifungal compounds have been identified and chemically characterized, and these from sexual (pathogenic) Epichloë species, rather than those utilized to enhance performance in turf and pasture industries. This review provides insight into the various strategies reported in identifying antifungal activity from Epichloë endophytes and, where described, the associated antifungal metabolites responsible for the activity.
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Affiliation(s)
- Krishni Fernando
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (G.C.S.); (S.J.R.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Priyanka Reddy
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (G.C.S.); (S.J.R.)
| | - German C. Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (G.C.S.); (S.J.R.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Simone J. Rochfort
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (G.C.S.); (S.J.R.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Kathryn M. Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (K.F.); (P.R.); (G.C.S.); (S.J.R.)
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Diversity Profiling of Seed Associated Endophytic Microbiome in Important Species of Caricaceae Family. MICROBIOLOGY RESEARCH 2021. [DOI: 10.3390/microbiolres12040057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Plant associated endophytic microbes play an important role in plant’s growth and development. After seed germination, the seed associated endophytes rapidly colonize the seedlings and help in their growth and protection against pathogens. This study was aimed to understand the diversity in the endophytic microbial population associated with the seeds of papaya (Carica papaya) and its wild relatives from Vasconcellea genus (family: Caricaceae). The species of Vasconcellea genus are widely used to introgress virus resistance in cultivated varieties of papaya. Hence, the diversity of seed associated endophytic microbes and their gene functional analysis was carried out through next generation sequencing of the microbial 16S rRNA and ITS sequences. Results: The 16S rRNA amplicon analysis revealed that the number of operational taxonomic units (OTUs) was higher for the endophytic bacteria, ranging between 144–204 when compared to 41–69 OTUs for the endophytic fungi. The bacterial phylum Proteobacteria was the most abundant seed associated phylum, with 64.7–72.8% abundance, across all four species of Caricaceae family, followed by Firmicutes (13.6–26.1%), Patescibacteria (1.1–2%) and Actinobacteria (0.7–2.7%). With respect to the diversity of bacteria by abundance indices, Vasconcellea goudotiana had the highest OTUs of 204, followed by 177 in V. cauliflora, 156 in V. cundinamarcensis, and 144 in C. papaya. The alpha diversity indices and functional analysis revealed the differences in the OTUs and the functional annotations among the above four plant species. The fungal OTUs were in the range of 41–69; however, only a small fraction of them could be taxonomically classified. Conclusion: Our microbiome studies reveal the differences in the seed associated endophytic microbial community across the four plant species of Caricaceae family. This study also unravels the composition of endophytic microbial population associated with the seeds of different plant species of Caricaceae family and their gene functions. It also provides an insight into both culturable and nonculturable endophytic microbes. Further this study reveals that domestication of Carica papaya might have resulted into reduced microbial diversity when compared to their wild relatives from Vasconcellea genus.
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Watson M, Bushley K, Seabloom EW, May G. Response of fungal endophyte communities within Andropogon gerardii (Big bluestem) to nutrient addition and herbivore exclusion. FUNGAL ECOL 2021. [DOI: 10.1016/j.funeco.2021.101043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Tian P, Xu W, Li C, Song H, Wang M, Schardl CL, Nan Z. Phylogenetic relationship and taxonomy of a hybrid Epichloë species symbiotic with Festuca sinensis. Mycol Prog 2020. [DOI: 10.1007/s11557-020-01618-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Determination of Loline Alkaloids and Mycelial Biomass in Endophyte-Infected Schedonorus Pratensis by Near-Infrared Spectroscopy and Chemometrics. Microorganisms 2020; 8:microorganisms8050776. [PMID: 32455703 PMCID: PMC7285352 DOI: 10.3390/microorganisms8050776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/14/2020] [Accepted: 05/19/2020] [Indexed: 11/16/2022] Open
Abstract
Near infrared spectroscopy (NIRS) is an accurate, fast and nondestructive technique whose use in predicting forage quality has become increasingly relevant in recent decades. Epichloë-infected grass varieties are commonly used in areas with high pest pressure due to their better performances compared to endophyte-free varieties. The insect resistance of Epichloë-infected grasses has been associated with four main groups of endophyte secondary metabolites: ergot alkaloids, indole-diterpenes, lolines and peramine. Concentrations of these alkaloids are usually measured with high performance liquid chromatography or gas chromatography analysis, which are accurate methods but relatively expensive and laborious. In this paper, we developed a rapid method based on NIRS to detect and quantify loline alkaloids in wild accessions of Schedonorus pratensis infected with the fungal endophyte Epichloë uncinata. The quantitative NIR equations obtained by modified partial least squares algorithm had coefficients of correlation of 0.90, 0.78, 0.85, 0.90 for N-acetylloline, N-acetylnorloline and N-formylloline and the sum of the three, respectively. The acquired NIR spectra were also used for developing an equation to predict in planta fungal biomass with a coefficient of correlation of 0.75. These results showed that the use of NIRS and chemometrics allows the quantification of loline alkaloids and mycelial biomass in a heterogeneous set of endophyte-infected meadow fescue samples.
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Gundel PE, Sun P, Charlton ND, Young CA, Miller TEX, Rudgers JA. Simulated folivory increases vertical transmission of fungal endophytes that deter herbivores and alter tolerance to herbivory in Poa autumnalis. ANNALS OF BOTANY 2020; 125:981-991. [PMID: 32010946 PMCID: PMC7218812 DOI: 10.1093/aob/mcaa021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/31/2020] [Indexed: 05/02/2023]
Abstract
BACKGROUND AND AIMS The processes that maintain variation in the prevalence of symbioses within host populations are not well understood. While the fitness benefits of symbiosis have clearly been shown to drive changes in symbiont prevalence, the rate of transmission has been less well studied. Many grasses host symbiotic fungi (Epichloë spp.), which can be transmitted vertically to seeds or horizontally via spores. These symbionts may protect plants against herbivores by producing alkaloids or by increasing tolerance to damage. Therefore, herbivory may be a key ecological factor that alters symbiont prevalence within host populations by affecting either symbiont benefits to host fitness or the symbiont transmission rate. Here, we addressed the following questions: Does symbiont presence modulate plant tolerance to herbivory? Does folivory increase symbiont vertical transmission to seeds or hyphal density in seedlings? Do plants with symbiont horizontal transmission have lower rates of vertical transmission than plants lacking horizontal transmission? METHODS We studied the grass Poa autumnalis and its symbiotic fungi in the genus Epichloë. We measured plant fitness (survival, growth, reproduction) and symbiont transmission to seeds following simulated folivory in a 3-year common garden experiment and surveyed natural populations that varied in mode of symbiont transmission. KEY RESULTS Poa autumnalis hosted two Epichloë taxa, an undescribed vertically transmitted Epichloë sp. PauTG-1 and E. typhina subsp. poae with both vertical and horizontal transmission. Simulated folivory reduced plant survival, but endophyte presence increased tolerance to damage and boosted fitness. Folivory increased vertical transmission and hyphal density within seedlings, suggesting induced protection for progeny of damaged plants. Across natural populations, the prevalence of vertical transmission did not correlate with symbiont prevalence or differ with mode of transmission. CONCLUSIONS Herbivory not only mediated the reproductive fitness benefits of symbiosis, but also promoted symbiosis prevalence by increasing vertical transmission of the fungus to the next generation. Our results reveal a new mechanism by which herbivores could influence the prevalence of microbial symbionts in host populations.
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Affiliation(s)
- Pedro E Gundel
- IFEVA-CONICET, Department of Ecology, College of Agronomy, University of Buenos Aires, Buenos Aires, Argentina
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
- For correspondence. E-mail
| | - Prudence Sun
- Department of Biosciences, Rice University, Houston, TX, USA
| | | | | | - Tom E X Miller
- Department of Biosciences, Rice University, Houston, TX, USA
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Hume DE, Stewart AV, Simpson WR, Johnson RD. Epichloëfungal endophytes play a fundamental role in New Zealand grasslands. J R Soc N Z 2020. [DOI: 10.1080/03036758.2020.1726415] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- David E. Hume
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand
| | - Alan V. Stewart
- PGG Wrightson Seeds Limited, Kimihia Research Centre, Lincoln, New Zealand
| | - Wayne R. Simpson
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand
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15
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Fuchs B, Kuhnert E, Krauss J. Contrasting Effects of Grass - Endophyte Chemotypes on a Tri-Trophic Cascade. J Chem Ecol 2020; 46:422-429. [PMID: 32125581 PMCID: PMC7205845 DOI: 10.1007/s10886-020-01163-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 02/05/2020] [Accepted: 02/18/2020] [Indexed: 12/26/2022]
Abstract
Systemic grass-endophytes of the genus Epichloë symbiotically infect the above-ground plant parts of many grass species, where they produce alkaloids in a grass- and endophyte-specific manner that are toxic or deterrent to herbivores. An increasing number of studies show cascading negative effects of endophyte-derived alkaloids that extend to higher trophic levels, harming beneficial insects, including those that control aphid populations. Lacewings are one of the major biological aphid controls, and are especially resistant to insecticides and pollutants, but their susceptibility to endophyte infection in the food chain has never been studied. Our study found variability in aphid population growth depending on the endophyte-grass chemotype, where aphid population growth was lowest on chemotypes known for producing high amounts of loline alkaloids. We also showed that larval and pupal development and mortality of the Common Green Lacewing (Chrysoperla carnea) was, in a non-choice experiment, not affected by endophyte infection in the food chain. This is a first indication that lacewings might be resistant to endophyte-derived alkaloids and could be robust biocontrol agents when applied together with endophyte-infected grass, possibly replacing chemical pesticides.
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Affiliation(s)
- Benjamin Fuchs
- Biodiversity Unit, University of Turku, 20014, Turku, Finland.
| | - Eric Kuhnert
- Institute for Organic Chemistry, BMWZ, Leibniz Universität Hannover, Schneiderberg 38, 30167, Hannover, Germany
| | - Jochen Krauss
- Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
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16
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Song QY, Li F, Nan ZB, Coulter JA, Wei WJ. Do Epichloë Endophytes and Their Grass Symbiosis Only Produce Toxic Alkaloids to Insects and Livestock? JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1169-1185. [PMID: 31922733 DOI: 10.1021/acs.jafc.9b06614] [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] [Indexed: 05/15/2023]
Abstract
Epichloë endophytes in forage grasses have attracted widespread attention and interest of chemistry researchers as a result of the various unique chemical structures and interesting biological activities of their secondary metabolites. This review describes the diversity of unique chemical structures of taxa from Epichloë endophytes and grass infected with Epichloë endophytes and demonstrates their reported biological activities. Until now, nearly 160 secondary metabolites (alkaloids, peptides, indole derivatives, pyrimidines, sesquiterpenoids, flavonoids, phenol and phenolic acid derivatives, aliphatic metabolites, sterols, amines and amides, and others) have been reported from Epichloë endophytes and grass infected with Epichloë endophytes. Among these, non-alkaloids account for half of the population of total metabolites, indicating that they also play an important role in Epichloë endophytes and grass infected with Epichloë endophytes. Also, a diverse array of secondary metabolites isolated from Epichloë endophytes and symbionts is a rich source for developing new pesticides and drugs. Bioassays disclose that, in addition to toxic alkaloids, the other metabolites isolated from Epichloë endophytes and symbionts have notable biological activities, such as antifungal, anti-insect, and phytotoxic activities. Accordingly, the biological functions of non-alkaloids should not be neglected in the future investigation of Epichloë endophytes and symbionts.
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Affiliation(s)
- Qiu-Yan Song
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology , Lanzhou University , Lanzhou , Gansu 730020 , People's Republic of China
| | - Fan Li
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology , Lanzhou University , Lanzhou , Gansu 730020 , People's Republic of China
| | - Zhi-Biao Nan
- State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology , Lanzhou University , Lanzhou , Gansu 730020 , People's Republic of China
| | - Jeffrey A Coulter
- Department of Agronomy and Plant Genetics , University of Minnesota , St. Paul , Minnesota 55108 , United States
| | - Wen-Jun Wei
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering , Lanzhou University , Lanzhou , Gansu 730000 , People's Republic of China
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17
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Hettiarachchige IK, Ludlow EJ, Ekanayake PN, Brohier ND, Sahab S, Sawbridge TI, Spangenberg GC, Guthridge KM. Generation of Epichloë Strains Expressing Fluorescent Proteins Suitable for Studying Host-Endophyte Interactions and Characterisation of a T-DNA Integration Event. Microorganisms 2019; 8:E54. [PMID: 31892173 PMCID: PMC7023320 DOI: 10.3390/microorganisms8010054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/20/2019] [Accepted: 12/24/2019] [Indexed: 11/17/2022] Open
Abstract
Methods for the identification and localisation of endophytic fungi are required to study the establishment, development, and progression of host-symbiont interactions, as visible reactions or disease symptoms are generally absent from host plants. Fluorescent proteins have proved valuable as reporter gene products, allowing non-invasive detection in living cells. This study reports the introduction of genes for two fluorescent proteins, green fluorescent protein (GFP) and red fluorescent protein, DsRed, into the genomes of two distinct perennial ryegrass (Lolium perenne L.)-associated Epichloë endophyte strains using A. tumefaciens-mediated transformation. Comprehensive characterisation of reporter gene-containing endophyte strains was performed using molecular genetic, phenotypic, and bioinformatic tools. A combination of long read and short read sequencing of a selected transformant identified a single complex T-DNA insert of 35,530 bp containing multiple T-DNAs linked together. This approach allowed for comprehensive characterisation of T-DNA integration to single-base resolution, while revealing the unanticipated nature of T-DNA integration in the transformant analysed. These reporter gene endophyte strains were able to establish and maintain stable symbiotum with the host. In addition, the same endophyte strain labelled with two different fluorescent proteins were able to cohabit the same plant. This knowledge can be used to provide the basis to develop strategies to gain new insights into the host-endophyte interaction through independent and simultaneous monitoring in planta throughout its life cycle in greater detail.
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Affiliation(s)
- Inoka K. Hettiarachchige
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
| | - Emma J. Ludlow
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
| | - Piyumi N. Ekanayake
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
| | - Natasha D. Brohier
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
| | - Sareena Sahab
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
| | - Timothy I. Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - German C. Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
- School of Applied Systems Biology, La Trobe University, Bundoora, VIC 3083, Australia
| | - Kathryn M. Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC 3083, Australia; (I.K.H.); (E.J.L.); (P.N.E.); (N.D.B.); (S.S.); (T.I.S.); (G.C.S.)
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18
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Wang R, Clarke BB, Belanger FC. Transcriptome Analysis of Choke Stroma and Asymptomatic Inflorescence Tissues Reveals Changes in Gene Expression in Both Epichloë festucae and Its Host Plant Festuca rubra subsp. rubra. Microorganisms 2019; 7:E567. [PMID: 31744076 PMCID: PMC6921078 DOI: 10.3390/microorganisms7110567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 02/07/2023] Open
Abstract
Many cool-season grasses have symbiotic relationships with Epichloë (Ascomycota, Clavicipitaceae) fungal endophytes that inhabit the intercellular spaces of the above-ground parts of the host plants. The presence of the Epichloë endophytes is generally beneficial to the hosts due to enhanced tolerance to biotic and abiotic stresses conferred by the endophytes. Many Epichloë spp. are asexual, and those infections always remain asymptomatic. However, some Epichloë spp. have a sexual stage and produce a macroscopic fruiting body, a stroma, that envelops the developing inflorescence causing a syndrome termed "choke disease". Here, we report a fungal and plant gene expression analysis of choke stroma tissue and asymptomatic inflorescence tissue of Epichloë festucae-infected strong creeping red fescue (Festuca rubra subsp. rubra). Hundreds of fungal genes and over 10% of the plant genes were differentially expressed when comparing the two tissue types. The differentially expressed fungal genes in the choke stroma tissue indicated a change in carbohydrate and lipid metabolism, as well as a change in expression of numerous genes for candidate effector proteins. Plant stress-related genes were up-regulated in the stroma tissue, suggesting the plant host was responding to the epiphytic stage of E. festucae as a pathogen.
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Affiliation(s)
| | | | - Faith C. Belanger
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901, USA; (R.W.); (B.B.C.)
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19
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Infection Rates and Alkaloid Patterns of Different Grass Species with Systemic Epichloë Endophytes. Appl Environ Microbiol 2019; 85:AEM.00465-19. [PMID: 31227553 DOI: 10.1128/aem.00465-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/14/2019] [Indexed: 01/05/2023] Open
Abstract
Symbiotic Epichloë species are fungal endophytes of cool-season grasses that can produce alkaloids with toxicity to vertebrates and/or invertebrates. Monitoring infections and presence of alkaloids in grasses infected with Epichloë species can provide an estimate of possible intoxication risks for livestock. We sampled 3,046 individuals of 13 different grass species in three regions on 150 study sites in Germany. We determined infection rates and used PCR to identify Epichloë species diversity based on the presence of different alkaloid biosynthesis genes, then confirmed the possible chemotypes with high-performance liquid chromatography (HPLC)/ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) measurements. Infections of Epichloë spp. were found in Festuca pratensis Huds. (81%), Festuca ovina L. aggregate (agg.) (73%), Lolium perenne L. (15%), Festuca rubra L. (15%) and Dactylis glomerata L. (8%). The other eight grass species did not appear to be infected. For the majority of Epichloë-infected L. perenne samples (98%), the alkaloids lolitrem B and peramine were present, but ergovaline was not detected, which was consistent with the genetic evaluation, as dmaW, the gene encoding the first step of the ergot alkaloid biosynthesis pathway, was absent. Epichloë uncinata in F. pratensis produced anti-insect loline compounds. The Epichloë spp. observed in the F. ovina agg. samples showed the greatest level of diversity, and different intermediates of the indole-diterpene pathway could be detected. Epichloë infection rates alone are insufficient to estimate intoxication risks for livestock, as other factors, like the ability of the endophyte to produce the alkaloids, also need to be assessed.IMPORTANCE Severe problems of livestock intoxication from Epichloë-infected forage grasses have been reported from New Zealand, Australia, and the United States, but much less frequently from Europe, and particularly not from Germany. Nevertheless, it is important to monitor infection rates and alkaloids of grasses with Epichloë fungi to estimate possible intoxication risks. Most studies focus on agricultural grass species like Lolium perenne and Festuca arundinacea, but other cool-season grass species can also be infected. We show that in Germany, infection rates and alkaloids differ between grass species and that some of the alkaloids can be toxic to livestock. Changes in grassland management due to changing climate, especially with a shift toward grasslands dominated with Epichloë-infected species such as Lolium perenne, may result in greater numbers of intoxicated livestock in the near future. We therefore suggest regular monitoring of grass species for infections and alkaloids and call for maintaining heterogenous grasslands for livestock.
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20
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Cagnano G, Roulund N, Jensen CS, Forte FP, Asp T, Leuchtmann A. Large Scale Screening of Epichloë Endophytes Infecting Schedonorus pratensis and Other Forage Grasses Reveals a Relation Between Microsatellite-Based Haplotypes and Loline Alkaloid Levels. FRONTIERS IN PLANT SCIENCE 2019; 10:765. [PMID: 31249582 PMCID: PMC6582706 DOI: 10.3389/fpls.2019.00765] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
Species belonging to the Festuca-Lolium complex are often naturally infected with endophytic fungi of genus Epichloë. Recent studies on endophytes have shown the beneficial roles of host-endophyte associations as protection against insect herbivores in agriculturally important grasses. However, large-scale screenings are crucial to identify animal friendly strains suitable for agricultural use. In this study we analyzed collected populations of meadow fescue (Schedonorus pratensis) from 135 different locations across Europe, 255 accessions from the United States Department of Agriculture and 96 accessions from The Nordic Genetic Resource Centre. The analysis also included representatives of S. arundinaceus, S. giganteus, and Lolium perenne. All plants were screened for the presence of Epichloë endophytes, resulting in a nursery of about 2500 infected plants from 176 different locations. Genetic diversity was investigated on 250 isolates using a microsatellite-based PCR fingerprinting assay at 7 loci, 5 of which were uncharacterized for these species. Phylogenetic and principal components analysis showed a strong interspecific genetic differentiation among isolates, and, with E. uncinata isolates, a small but significant correlation between genetic diversity and geographical effect (r = 0.227) was detected. Concentrations of loline alkaloids were measured in 218 infected meadow fescue plants. Average amount of total loline and the proportions of the single loline alkaloids differed significantly among endophyte haplotypes (P < 0.005). This study provides insight into endophyte genetic diversity and geographic variation in Europe and a reference database of allele sizes for fast discrimination of isolates. We also discuss the possibility of multiple hybridization events as a source of genetic and alkaloid variation observed in E. uncinata.
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Affiliation(s)
- Giovanni Cagnano
- DLF Trifolium A/S, Roskilde, Denmark
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | | | | | - Flavia Pilar Forte
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | - Torben Asp
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
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22
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Hettiarachchige IK, Elkins AC, Reddy P, Mann RC, Guthridge KM, Sawbridge TI, Forster JW, Spangenberg GC. Genetic modification of asexual Epichloë endophytes with the perA gene for peramine biosynthesis. Mol Genet Genomics 2018; 294:315-328. [PMID: 30443676 DOI: 10.1007/s00438-018-1510-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
Development of grass-endophyte associations with minimal or no detrimental effects in combination with beneficial characteristics is important for pastoral agriculture. The feasibility of enhancing production of an endophyte-derived beneficial alkaloid through introduction of an additional gene copy was assessed in a proof-of-concept study. Sexual and asexual Epichloë species that form symbiotic associations with cool-season grasses of the Poaceae sub-family Pooideae produce bioactive alkaloids that confer resistance to herbivory by a number of organisms. Of these, peramine is thought to be crucial for protection of perennial ryegrass (Lolium perenne L.) from the Argentinian stem weevil, an economically important exotic pest in New Zealand, contributing significantly to pasture persistence. A single gene (perA) has been identified as solely responsible for peramine biosynthesis and is distributed widely across Epichloë taxa. In the present study, a functional copy of the perA gene was introduced into three recipient endophyte genomes by Agrobacterium tumefaciens-mediated transformation. The target strains included some that do not produce peramine, and others containing different perA gene copies. Mitotically stable transformants generated from all three endophyte strains were able to produce peramine in culture and in planta at variable levels. In summary, this study provides an insight into the potential for artificial combinations of alkaloid biosynthesis in a single endophyte strain through transgenesis, as well as the possibility of using novel genome editing techniques to edit the perA gene of non-peramine producing strains.
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Affiliation(s)
| | - Aaron C Elkins
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Priyanka Reddy
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Ross C Mann
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Kathryn M Guthridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia
| | - Timothy I Sawbridge
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia.,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia
| | - John W Forster
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia.,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia
| | - German C Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 3083, Bundoora, VIC, Australia. .,School of Applied Systems Biology, La Trobe University, 3086, Bundoora, VIC, Australia.
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23
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Xia C, Li N, Zhang Y, Li C, Zhang X, Nan Z. Role of Epichloë Endophytes in Defense Responses of Cool-Season Grasses to Pathogens: A Review. PLANT DISEASE 2018; 102:2061-2073. [PMID: 30270751 DOI: 10.1094/pdis-05-18-0762-fe] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Various cool-season grasses are infected by Epichloë endophyte, and this symbiotic relationship is always of benefit to the host grass due to an increased resistance to abiotic and biotic stresses. Fungal diseases adversely affect the yield, quality, and economic benefits of rangelands, which affects the production of animal husbandry. Therefore, it is imperative to breed resistant cultivars and to better understand the role of fungal endophytes in order to protect grasses against pathogens. The present review introduces research regarding how these endophytes affect the growth of pathogens in vitro and how they change the resistance of host plants to plant diseases. From the perspective of physical defense, changes in physiological indexes, and secretion of chemical compounds, we summarize the potential mechanisms by which endophytes are able to enhance the disease resistance of a host grass. Through these, we aim to establish a solid theoretical foundation for plant disease control and disease resistance breeding by application of fungal endophytes. A broader understanding of fungal endophyte effects on hosts could create a new opportunity for managing or introducing fungal symbioses in both agronomic or non-agronomic ecosystems.
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Affiliation(s)
- Chao Xia
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
| | - Nana Li
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
| | - Yawen Zhang
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
| | - Chunjie Li
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
| | - Xingxu Zhang
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agro-Ecosystems; Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture; and College of Pastoral Agricultural Science and Technology, Lanzhou University, P. O. Box 61, Lanzhou 730020, P. R. China
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24
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Bamisile BS, Dash CK, Akutse KS, Keppanan R, Wang L. Fungal Endophytes: Beyond Herbivore Management. Front Microbiol 2018; 9:544. [PMID: 29628919 PMCID: PMC5876286 DOI: 10.3389/fmicb.2018.00544] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/09/2018] [Indexed: 11/13/2022] Open
Abstract
The incorporation of entomopathogenic fungi as biocontrol agents into Integrated Pest Management (IPM) programs without doubt, has been highly effective. The ability of these fungal pathogens such as Beauveria bassiana and Metarhizium anisopliae to exist as endophytes in plants and protect their colonized host plants against the primary herbivore pests has widely been reported. Aside this sole role of pest management that has been traditionally ascribed to fungal endophytes, recent findings provided evidence of other possible functions as plant yield promoter, soil nutrient distributor, abiotic stress and drought tolerance enhancer in plants. However, reports on these additional important effects of fungal endophytes on the colonized plants remain scanty. In this review, we discussed the various beneficial effects of endophytic fungi on the host plants and their primary herbivore pests; as well as some negative effects that are relatively unknown. We also highlighted the prospects of our findings in further increasing the acceptance of fungal endophytes as an integral part of pest management programs for optimized crop production.
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Affiliation(s)
- Bamisope S. Bamisile
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management for Fujian and Taiwan Crops, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chandra K. Dash
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management for Fujian and Taiwan Crops, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
- Department of Entomology, Faculty of Agriculture, Sylhet Agricultural University, Sylhet, Bangladesh
| | - Komivi S. Akutse
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Ravindran Keppanan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management for Fujian and Taiwan Crops, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Liande Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Laboratory of Integrated Pest Management for Fujian and Taiwan Crops, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
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25
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Shi C, An S, Yao Z, Young CA, Panaccione DG, Lee ST, Schardl CL, Li C. Toxin-producing Epichloë bromicola strains symbiotic with the forage grass Elymus dahuricus in China. Mycologia 2018. [PMID: 29528270 DOI: 10.1080/00275514.2018.1426941] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cool-season grasses (Poaceae subfamily Poöideae) are an important forage component for livestock in western China, and many have seed-transmitted symbionts of the genus Epichloë, fungal endophytes that are broadly distributed geographically and in many tribes of the Poöideae. Epichloë strains can produce any of several classes of alkaloids, of which ergot alkaloids and indole-diterpenes can be toxic to mammalian and invertebrate herbivores, whereas lolines and peramine are more selective against invertebrates. The authors characterized genotypes and alkaloid profiles of Epichloë bromicola isolates symbiotic with Elymus dahuricus, an important forage grass in rangelands of China. The endophyte was seed-transmitted and occasionally produced fruiting bodies (stromata), but its sexual state was not observed on this host. The genome sequence of E. bromicola isolate E7626 from El. dahuricus in Xinjiang Province revealed gene sets for peramine, ergot alkaloids, and indole-diterpenes. In multiplex polymerase chain reaction (PCR) screens of El. dahuricus-endophyte isolates from Beijing and two locations in Shanxi Province, most were also positive for these genes. Ergovaline and other ergot alkaloids, terpendoles and other indole-diterpenes, and peramine were confirmed in El. dahuricus plants with E. bromicola. The presence of ergot alkaloids and indole-diterpenes in this grass is a potential concern for managers of grazing livestock.
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Affiliation(s)
- Chong Shi
- a College of Grassland and Environmental Science, Xinjiang Agricultural University , Urumqi , Xinjiang , China 830052
| | - Shazhou An
- a College of Grassland and Environmental Science, Xinjiang Agricultural University , Urumqi , Xinjiang , China 830052
| | - Zhengpei Yao
- b College of Agriculture, Xinjiang Agricultural University , Urumqi , Xinjiang , China 830052
| | - Carolyn A Young
- c Noble Research Institute , 2510 Sam Noble Parkway, Ardmore , Oklahoma 73401
| | - Daniel G Panaccione
- d Division of Plant and Soil Sciences , West Virginia University , Morgantown , West Virginia 26506-6108
| | - Stephen T Lee
- e Poisonous Plant Research Laboratory, Agricultural Research Service , United States Department of Agriculture , 1150 E. 1400 N., Logan , Utah 84341
| | - Christopher L Schardl
- f Department of Plant Pathology , University of Kentucky , Lexington , Kentucky 40546-0312
| | - Chunjie Li
- g State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University , Lanzhou , Gansu , China 730000
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Hernández-Agramonte IM, Semmartin M, Omacini M, Durante M, Gundel PE, De Battista J. A fungal endophyte of a palatable grass affects preference of large herbivores. AUSTRAL ECOL 2017. [DOI: 10.1111/aec.12554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
| | - María Semmartin
- IFEVA; Facultad de Agronomía; CONICET; Universidad de Buenos Aires; Av. San Martín 4453 C1417DSE Buenos Aires Argentina
| | - Marina Omacini
- IFEVA; Facultad de Agronomía; CONICET; Universidad de Buenos Aires; Av. San Martín 4453 C1417DSE Buenos Aires Argentina
| | - Martín Durante
- INTA Instituto Nacional de Tecnología Agropecuaria, EEA Concepción del Uruguay Entre Ríos; Concepcion del Uruguay Argentina
| | - Pedro E. Gundel
- IFEVA; Facultad de Agronomía; CONICET; Universidad de Buenos Aires; Av. San Martín 4453 C1417DSE Buenos Aires Argentina
| | - José De Battista
- INTA Instituto Nacional de Tecnología Agropecuaria, EEA Concepción del Uruguay Entre Ríos; Concepcion del Uruguay Argentina
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Ghimire SR, Rudgers JA, Charlton ND, Young C, Craven KD. Prevalence of an intraspecificNeotyphodiumhybrid in natural populations of stout wood reed (Cinna arundinaceaL.) from eastern North America. Mycologia 2017; 103:75-84. [DOI: 10.3852/10-154] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sita R. Ghimire
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Jennifer A. Rudgers
- Department of Ecology and Evolutionary Biology, Rice University, Houston, Texas 77005
| | - Nikki D. Charlton
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Carolyn Young
- Forage Improvement Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
| | - Kelly D. Craven
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401
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Qin J, Gao Y, Liu H, Zhou Y, Ren A, Gao Y. Effect of Endophyte Infection and Clipping Treatment on Resistance and Tolerance of Achnatherum sibiricum. Front Microbiol 2016; 7:1988. [PMID: 28018319 PMCID: PMC5156843 DOI: 10.3389/fmicb.2016.01988] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/28/2016] [Indexed: 12/24/2022] Open
Abstract
It is well-documented that endophytes can enhance the resistance of agronomical grasses, such as tall fescue and perennial ryegrass to herbivory. For native grasses, however, the related reports are limited, and the conclusions are variable. Achnatherum sibiricum is a grass native to the Inner Mongolian steppe. This grass is highly infected by endophytes but does not produce detectable endophyte-related alkaloids known under normal conditions. In this study, the contributions of endophytes to the resistance of A. sibiricum to Locusta migratoria were studied. We found that locusts preferred EF (endophyte-free) plants to EI (endophyte-infected) plants, and the weight of locusts fed on EI plants was significantly lower than those fed on EF plants. Hence, endophyte infection significantly enhanced the resistance of the host to L. migratoria. Endophyte infection significantly decreased the concentration of soluble sugar and amino acids while significantly increased the concentration of total phenolic content, and these metabolites may contribute to herbivore resistance of the host. The clipping treatment further strengthened the locust resistance advantage of EI over EF plants. After clipping, the weight of the locusts fed on EI plants significantly decreased compared with those fed on unclipped plants, whereas the weight of the locusts fed on EF plants increased significantly. The results suggested that endophyte infection could increase herbivore resistance while decreasing the tolerance of the host grass by mechanisms apart from endophyte-conferred alkaloid defense.
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Affiliation(s)
- Junhua Qin
- College of Life Sciences Nankai University, Tianjin, China
| | - Yuan Gao
- College of Life Sciences Nankai University, Tianjin, China
| | - Hui Liu
- College of Life Sciences Nankai University, Tianjin, China
| | - Yong Zhou
- College of Life Sciences Nankai University, Tianjin, China
| | - Anzhi Ren
- College of Life Sciences Nankai University, Tianjin, China
| | - Yubao Gao
- College of Life Sciences Nankai University, Tianjin, China
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Laitinen RK, Hellström KO, Wäli PR. Context-dependent outcomes of subarctic grass-endophyte symbiosis. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2016.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Santangelo JS, Kotanen PM. Nonsystemic fungal endophytes increase survival but reduce tolerance to simulated herbivory in subarctic
Festuca rubra. Ecosphere 2016. [DOI: 10.1002/ecs2.1260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- James S. Santangelo
- Department of Biology University of Toronto Mississauga 3359 Mississauga RoadMississaugaOntario L5L 1C6 Canada
| | - Peter M. Kotanen
- Department of Ecology and Evolutionary Biology University of Toronto Mississauga 3359 Mississauga RoadMississaugaOntarioL5L 1C6 Canada
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Hume DE, Ryan GD, Gibert A, Helander M, Mirlohi A, Sabzalian MR. Epichloë Fungal Endophytes for Grassland Ecosystems. SUSTAINABLE AGRICULTURE REVIEWS 2016. [DOI: 10.1007/978-3-319-26777-7_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Moore JR, Pratley JE, Mace WJ, Weston LA. Variation in Alkaloid Production from Genetically Diverse Lolium Accessions Infected with Epichloë Species. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:10355-65. [PMID: 26550846 DOI: 10.1021/acs.jafc.5b03089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Widespread infection of Epichloë occultans in annual ryegrass in Australia suggests that infection provides its weedy host, Lolium rigidum, some ecological advantage. Initial studies determined the distribution and profiles of known Epichloë alkaloids (epoxy-janthitrems, ergovaline, lolines, lolitrem B, and peramine) in plant extracts using a combination of GC-FID and HPLC techniques utilizing a single accession of Australian L. rigidum. However, the lolines N-acetylnorloline (NANL) and N-formylloline (NFL) were the only alkaloids detected and were highly concentrated in the immature inflorescences of mature plants. Additional glasshouse studies subjected a wide range of Australian L. rigidum haplotypes and international annual Lolium accessions to a suite of analyses to determine alkaloid levels and profiles. Again, NFL and NANL were the key lolines produced, with NFL consistently predominating. Considerable variation in alkaloid production was found both within and between biotypes and accessions evaluated under identical conditions, at the same maturation stage and on the same tissue type. The pyrrolopyrazine alkaloid peramine was also present in 8 out of 17 Australian biotypes of L. rigidum and 7 out of 33 international accessions infected with Epichloë spp.; the highest peramine concentrations were observed in seed extracts from L. rigidum collected from Australia. This study represents the first report of alkaloids from a geographically diverse collection of annual ryegrass germplasm infected with Epichloë spp. when grown under identical controlled conditions.
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Affiliation(s)
- Joseph R Moore
- Graham Centre for Agricultural Innovation (An alliance between NSW Department of Primary Industries and Charles Sturt University), School of Agricultural and Wine Sciences, Charles Sturt University , Wagga Wagga, New South Wales 2650, Australia
| | - James E Pratley
- Graham Centre for Agricultural Innovation (An alliance between NSW Department of Primary Industries and Charles Sturt University), School of Agricultural and Wine Sciences, Charles Sturt University , Wagga Wagga, New South Wales 2650, Australia
| | - Wade J Mace
- Grasslands Research Centre, AgResearch Limited , Palmerston North 4442, New Zealand
| | - Leslie A Weston
- Graham Centre for Agricultural Innovation (An alliance between NSW Department of Primary Industries and Charles Sturt University), School of Agricultural and Wine Sciences, Charles Sturt University , Wagga Wagga, New South Wales 2650, Australia
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Vandegrift R, Roy BA, Pfeifer-Meister L, Johnson BR, Bridgham SD. The herbaceous landlord: integrating the effects of symbiont consortia within a single host. PeerJ 2015; 3:e1379. [PMID: 26557442 PMCID: PMC4636405 DOI: 10.7717/peerj.1379] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/14/2015] [Indexed: 11/20/2022] Open
Abstract
Plants are typically infected by a consortium of internal fungal associates, including endophytes in their leaves, as well as arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) in their roots. It is logical that these organisms will interact with each other and the abiotic environment in addition to their host, but there has been little work to date examining the interactions of multiple symbionts within single plant hosts, or how the relationships among symbionts and their host change across environmental conditions. We examined the grass Agrostis capillaris in the context of a climate manipulation experiment in prairies in the Pacific Northwest, USA. Each plant was tested for presence of foliar endophytes in the genus Epichloë, and we measured percent root length colonized (PRLC) by AMF and DSE. We hypothesized that the symbionts in our system would be in competition for host resources, that the outcome of that competition could be driven by the benefit to the host, and that the host plants would be able to allocate carbon to the symbionts in such a way as to maximize fitness benefit within a particular environmental context. We found a correlation between DSE and AMF PRLC across climatic conditions; we also found a fitness cost to increasing DSE colonization, which was negated by presence of Epichloë endophytes. These results suggest that selective pressure on the host is likely to favor host/symbiont relationships that structure the community of symbionts in the most beneficial way possible for the host, not necessarily favoring the individual symbiont that is most beneficial to the host in isolation. These results highlight the need for a more integrative, systems approach to the study of host/symbiont consortia.
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Affiliation(s)
- Roo Vandegrift
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | - Bitty A. Roy
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
| | - Laurel Pfeifer-Meister
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
- Environmental Science Institute, University of Oregon, Eugene, OR, United States
| | - Bart R. Johnson
- Department of Landscape Architecture, University of Oregon, Eugene, OR, United States
| | - Scott D. Bridgham
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR, United States
- Environmental Science Institute, University of Oregon, Eugene, OR, United States
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Identification of Acremonium isolates from grapevines and evaluation of their antagonism towards Plasmopara viticola. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1082-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Genetics, genomics and evolution of ergot alkaloid diversity. Toxins (Basel) 2015; 7:1273-302. [PMID: 25875294 PMCID: PMC4417967 DOI: 10.3390/toxins7041273] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/02/2015] [Accepted: 04/08/2015] [Indexed: 01/18/2023] Open
Abstract
The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary) metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization). The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine.
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36
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Berry D, Takach JE, Schardl CL, Charlton ND, Scott B, Young CA. Disparate independent genetic events disrupt the secondary metabolism gene perA in certain symbiotic Epichloë species. Appl Environ Microbiol 2015; 81:2797-807. [PMID: 25681180 PMCID: PMC4375322 DOI: 10.1128/aem.03721-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/05/2015] [Indexed: 01/23/2023] Open
Abstract
Peramine is an insect-feeding deterrent produced by Epichloë species in symbiotic association with C3 grasses. The perA gene responsible for peramine synthesis encodes a two-module nonribosomal peptide synthetase. Alleles of perA are found in most Epichloë species; however, peramine is not produced by many perA-containing Epichloë isolates. The genetic basis of these peramine-negative chemotypes is often unknown. Using PCR and DNA sequencing, we analyzed the perA genes from 72 Epichloë isolates and identified causative mutations of perA null alleles. We found nonfunctional perA-ΔR* alleles, which contain a transposon-associated deletion of the perA region encoding the C-terminal reductase domain, are widespread within the Epichloë genus and represent a prevalent mutation found in nonhybrid species. Disparate phylogenies of adjacent A2 and T2 domains indicated that the deletion of the reductase domain (R*) likely occurred once and early in the evolution of the genus, and subsequently there have been several recombinations between those domains. A number of novel point, deletion, and insertion mutations responsible for abolishing peramine production in full-length perA alleles were also identified. The regions encoding the first and second adenylation domains (A1 and A2, respectively) were common sites for such mutations. Using this information, a method was developed to predict peramine chemotypes by combining PCR product size polymorphism analysis with sequencing of the perA adenylation domains.
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Affiliation(s)
- Daniel Berry
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | | | | | | | - Barry Scott
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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Repussard C, Zbib N, Tardieu D, Guerre P. Ergovaline and lolitrem B concentrations in perennial ryegrass in field culture in southern France: distribution in the plant and impact of climatic factors. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:12707-12712. [PMID: 25526521 DOI: 10.1021/jf504581y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Perennial ryegrass (Lolium perenne) infected by Epichloë festucae var. lolii contains alkaloids that are responsible for toxicosis in several countries, but few cases are reported in Europe. Lolitrem B is generally the most abundant alkaloid and is recognized to be responsible for livestock staggers, whereas ergovaline is less frequently documented in perennial ryegrass. Lolitrem B and ergovaline were monitored over a three-year period in endophyte-infected perennial ryegrass 'Samson' sown in southern France. Alkaloid concentrations were strongly influenced by the stage of maturity of the plant; maximum concentrations were always measured at the fully ripe stage. Over the three years of analysis, variations in lolitrem B in the whole plant at the fully ripe stage were low (from 1296 to maximum 1871 μg/kg dry matter), whereas ergovaline varied considerably (from 526 to 2322 μg/kg dry matter), suggesting that abiotic factors play a key role in determining ergovaline levels in endophyte-infected perennial ryegrass.
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Affiliation(s)
- Céline Repussard
- Université de Toulouse, INP, ENVT, UR Mycotoxicologie, F-31076 Toulouse, France
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38
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Shymanovich T, Saari S, Lovin ME, Jarmusch AK, Jarmusch SA, Musso AM, Charlton ND, Young CA, Cech NB, Faeth SH. Alkaloid variation among epichloid endophytes of sleepygrass (Achnatherum robustum) and consequences for resistance to insect herbivores. J Chem Ecol 2014; 41:93-104. [PMID: 25501262 DOI: 10.1007/s10886-014-0534-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Revised: 08/30/2014] [Accepted: 12/02/2014] [Indexed: 10/24/2022]
Abstract
Epichloid endophytes are well known symbionts of many cool-season grasses that may alleviate environmental stresses for their hosts. For example, endophytes produce alkaloid compounds that may be toxic to invertebrate or vertebrate herbivores. Achnatherum robustum, commonly called sleepygrass, was aptly named due to the presence of an endophyte that causes toxic effects to livestock and wildlife. Variation in alkaloid production observed in two A. robustum populations located near Weed and Cloudcroft in the Lincoln National Forest, New Mexico, suggests two different endophyte species are present in these populations. Genetic analyses of endophyte-infected samples revealed major differences in the endophyte alkaloid genetic profiles from the two populations, which were supported with chemical analyses. The endophyte present in the Weed population was shown to produce chanoclavine I, paspaline, and terpendoles, so thus resembles the previously described Epichloë funkii. The endophyte present in the Cloudcroft population produces chanoclavineI, ergonovine, lysergic acid amide, and paspaline, and is an undescribed endophyte species. We observed very low survival rates for aphids feeding on plants infected with the Cloudcroft endophyte, while aphid survival was better on endophyte infected plants in the Weed population. This observation led to the hypothesis that the alkaloid ergonovine is responsible for aphid mortality. Direct testing of aphid survival on oat leaves supplemented with ergonovine provided supporting evidence for this hypothesis. The results of this study suggest that alkaloids produced by the Cloudcroft endophyte, specifically ergonovine, have insecticidal properties.
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Affiliation(s)
- Tatsiana Shymanovich
- Department of Biology, University of North Carolina Greensboro, 312 Eberhart Bldg., Greensboro, NC, 27412, USA,
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Young CA, Charlton ND, Takach JE, Swoboda GA, Trammell MA, Huhman DV, Hopkins AA. Characterization of Epichloë coenophiala within the US: are all tall fescue endophytes created equal? Front Chem 2014; 2:95. [PMID: 25408942 PMCID: PMC4219521 DOI: 10.3389/fchem.2014.00095] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/14/2014] [Indexed: 11/13/2022] Open
Abstract
Tall fescue (Lolium arundinaceum) is a valuable and broadly adapted forage grass that occupies approximately 14 million hectares across the United States. A native to Europe, tall fescue was likely introduced into the US around the late 1800's. Much of the success of tall fescue can be attributed to Epichloë coenophiala (formerly Neotyphodium coenophialum) a seed borne symbiont that aids in host persistence. Epichloë species are capable of producing a range of alkaloids (ergot alkaloids, indole-diterpenes, lolines, and peramine) that provide protection to the plant host from herbivory. Unfortunately, most tall fescue within the US, commonly referred to as "Kentucky-31" (KY31), harbors the endophyte E. coenophiala that causes toxicity to grazing livestock due to the production of ergot alkaloids. Molecular analyses of tall fescue endophytes have identified four independent associations, representing tall fescue with E. coenophiala, Epichloë sp. FaTG-2, Epichloë sp. FaTG-3, or Epichloë sp. FaTG-4. Each of these Epichloë species can be further distinguished based on genetic variation that equates to differences in the alkaloid gene loci. Tall fescue samples were evaluated using markers to simple sequence repeats (SSRs) and alkaloid biosynthesis genes to determine endophyte strain variation present within continental US. Samples represented seed and tillers from the Suiter farm (Menifee County, KY), which is considered the originating site of KY31, as well as plant samples collected from 14 states, breeder's seed and plant introduction lines (National Plant Germplasm System, NPGS). This study revealed two prominent E. coenophiala genotypes based on presence of alkaloid biosynthesis genes and SSR markers and provides insight into endophyte variation within continental US across historical and current tall fescue samples.
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Affiliation(s)
- Carolyn A Young
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - Nikki D Charlton
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - Johanna E Takach
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - Ginger A Swoboda
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - Michael A Trammell
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - David V Huhman
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
| | - Andrew A Hopkins
- The Samuel Roberts Noble Foundation, Forage Improvement Division Ardmore, OK, USA
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Leuchtmann A, Bacon CW, Schardl CL, White JF, Tadych M. Nomenclatural realignment of Neotyphodium species with genus Epicholë. Mycologia 2014; 106:202-15. [PMID: 24459125 DOI: 10.3852/13-251] [Citation(s) in RCA: 297] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Nomenclatural rule changes in the International Code of Nomenclature for algae, fungi and plants, adopted at the 18th International Botanical Congress in Melbourne, Australia, in 2011, provide for a single name to be used for each fungal species. The anamorphs of Epichloë species have been classified in genus Neotyphodium, the form genus that also includes most asexual Epichloë descendants. A nomenclatural realignment of this monophyletic group into one genus would enhance a broader understanding of the relationships and common features of these grass endophytes. Based on the principle of priority of publication we propose to classify all members of this clade in the genus Epichloë. We have reexamined classification of several described Epichloë and Neotyphodium species and varieties and propose new combinations and states. In this treatment we have accepted 43 unique taxa in Epichloë, including distinct species, subspecies, and varieties. We exclude from Epichloë the two taxa Neotyphodium starrii, as nomen dubium, and Neotyphodium chilense, as an unrelated taxon.
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Borer ET, Kinkel LL, May G, Seabloom EW. The world within: Quantifying the determinants and outcomes of a host's microbiome. Basic Appl Ecol 2013. [DOI: 10.1016/j.baae.2013.08.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Schardl CL, Florea S, Pan J, Nagabhyru P, Bec S, Calie PJ. The epichloae: alkaloid diversity and roles in symbiosis with grasses. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:480-8. [PMID: 23850071 PMCID: PMC3874428 DOI: 10.1016/j.pbi.2013.06.012] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 06/11/2013] [Accepted: 06/14/2013] [Indexed: 05/20/2023]
Abstract
Epichloae (Epichloë and Neotyphodium species; Clavicipitaceae) are fungi that live in systemic symbioses with cool-season grasses, and many produce alkaloids that are deterrent or toxic to herbivores. The epichloae colonize much of the aerial plant tissues, and most benignly colonize host seeds to transmit vertically. Of their four chemical classes of alkaloids, the ergot alkaloids and indole-diterpenes are active against mammals and insects, whereas peramine and lolines specifically affect insects. Comparative genomic analysis of Clavicipitaceae reveals a distinctive feature of the epichloae, namely, large repeat blocks in their alkaloid biosynthesis gene loci. Such repeat blocks can facilitate gene losses, mutations, and duplications, thus enhancing diversity of alkaloid structures within each class. We suggest that alkaloid diversification is selected especially in the vertically transmissible epichloae.
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Affiliation(s)
- Christopher L Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546-0312, USA.
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Chemical Ecology Mediated by Fungal Endophytes in Grasses. J Chem Ecol 2013; 39:962-8. [DOI: 10.1007/s10886-013-0310-3] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 05/24/2013] [Accepted: 06/05/2013] [Indexed: 12/13/2022]
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Schardl CL, Young CA, Pan J, Florea S, Takach JE, Panaccione DG, Farman ML, Webb JS, Jaromczyk J, Charlton ND, Nagabhyru P, Chen L, Shi C, Leuchtmann A. Currencies of mutualisms: sources of alkaloid genes in vertically transmitted epichloae. Toxins (Basel) 2013; 5:1064-88. [PMID: 23744053 PMCID: PMC3717770 DOI: 10.3390/toxins5061064] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/17/2013] [Accepted: 05/29/2013] [Indexed: 11/17/2022] Open
Abstract
The epichloae (Epichloë and Neotyphodium species), a monophyletic group of fungi in the family Clavicipitaceae, are systemic symbionts of cool-season grasses (Poaceae subfamily Poöideae). Most epichloae are vertically transmitted in seeds (endophytes), and most produce alkaloids that attack nervous systems of potential herbivores. These protective metabolites include ergot alkaloids and indole-diterpenes (tremorgens), which are active in vertebrate systems, and lolines and peramine, which are more specific against invertebrates. Several Epichloë species have been described which are sexual and capable of horizontal transmission, and most are vertically transmissible also. Asexual epichloae are mainly or exclusively vertically transmitted, and many are interspecific hybrids with genomic contributions from two or three ancestral Epichloë species. Here we employ genome-scale analyses to investigate the origins of biosynthesis gene clusters for ergot alkaloids (EAS), indole-diterpenes (IDT), and lolines (LOL) in 12 hybrid species. In each hybrid, the alkaloid-gene and housekeeping-gene relationships were congruent. Interestingly, hybrids frequently had alkaloid clusters that were rare in their sexual ancestors. Also, in those hybrids that had multiple EAS, IDT or LOL clusters, one cluster lacked some genes, usually for late pathway steps. Possible implications of these findings for the alkaloid profiles and endophyte ecology are discussed.
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Affiliation(s)
- Christopher L. Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
| | - Carolyn A. Young
- Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA; E-Mails: (C.A.Y.); (J.E.T.); (N.D.C.)
| | - Juan Pan
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
| | - Simona Florea
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
| | - Johanna E. Takach
- Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA; E-Mails: (C.A.Y.); (J.E.T.); (N.D.C.)
| | - Daniel G. Panaccione
- Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26506, USA; E-Mail:
| | - Mark L. Farman
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
| | - Jennifer S. Webb
- Advanced Genetic Technologies Center, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.S.W.); (J.J.)
| | - Jolanta Jaromczyk
- Advanced Genetic Technologies Center, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.S.W.); (J.J.)
| | - Nikki D. Charlton
- Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA; E-Mails: (C.A.Y.); (J.E.T.); (N.D.C.)
| | - Padmaja Nagabhyru
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
| | - Li Chen
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
- School of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China
| | - Chong Shi
- Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, USA; E-Mails: (J.P.); (S.F.); (M.L.F.); (P.N.); (L.C.); (C.S.)
- School of Grassland & Environmental Science, Xinjiang Agricultural University, Urumqi 830052, China
| | - Adrian Leuchtmann
- Institute of Integrative Biology, ETH Zürich, Zürich CH-8092, Switzerland; E-Mail:
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Panaccione DG, Beaulieu WT, Cook D. Bioactive alkaloids in vertically transmitted fungal endophytes. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12076] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Daniel G. Panaccione
- Division of Plant & Soil Sciences; West Virginia University; 1090 Agricultural Sciences Building Morgantown WV 26506-6108 USA
| | | | - Daniel Cook
- USDA ARS Poisonous Plant Research Laboratory; Logan UT USA
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Schardl CL, Young CA, Hesse U, Amyotte SG, Andreeva K, Calie PJ, Fleetwood DJ, Haws DC, Moore N, Oeser B, Panaccione DG, Schweri KK, Voisey CR, Farman ML, Jaromczyk JW, Roe BA, O'Sullivan DM, Scott B, Tudzynski P, An Z, Arnaoudova EG, Bullock CT, Charlton ND, Chen L, Cox M, Dinkins RD, Florea S, Glenn AE, Gordon A, Güldener U, Harris DR, Hollin W, Jaromczyk J, Johnson RD, Khan AK, Leistner E, Leuchtmann A, Li C, Liu J, Liu J, Liu M, Mace W, Machado C, Nagabhyru P, Pan J, Schmid J, Sugawara K, Steiner U, Takach JE, Tanaka E, Webb JS, Wilson EV, Wiseman JL, Yoshida R, Zeng Z. Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the clavicipitaceae reveals dynamics of alkaloid loci. PLoS Genet 2013; 9:e1003323. [PMID: 23468653 PMCID: PMC3585121 DOI: 10.1371/journal.pgen.1003323] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/31/2012] [Indexed: 01/01/2023] Open
Abstract
The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses.
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Schardl CL, Young CA, Faulkner JR, Florea S, Pan J. Chemotypic diversity of epichloae, fungal symbionts of grasses. FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2011.04.005] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gooneratne SR, Patchett BJ, Wellby M, Fletcher LR. Excretion of loline alkaloids in urine and faeces of sheep dosed with meadow fescue (Festuca pratensis) seed containing high concentrations of loline alkaloids. N Z Vet J 2012; 60:176-82. [DOI: 10.1080/00480169.2011.644189] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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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: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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González V, Tello ML. The endophytic mycota associated with Vitis vinifera in central Spain. FUNGAL DIVERS 2010. [DOI: 10.1007/s13225-010-0073-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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