1
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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
| |
Collapse
|
2
|
Negård M, Uhlig S, Kauserud H, Andersen T, Høiland K, Vrålstad T. Links between Genetic Groups, Indole Alkaloid Profiles and Ecology within the Grass-Parasitic Claviceps purpurea Species Complex. Toxins (Basel) 2015; 7:1431-56. [PMID: 25928134 PMCID: PMC4448156 DOI: 10.3390/toxins7051431] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/24/2022] Open
Abstract
The grass parasitic fungus Claviceps purpurea sensu lato produces sclerotia with toxic indole alkaloids. It constitutes several genetic groups with divergent habitat preferences that recently were delimited into separate proposed species. We aimed to 1) analyze genetic variation of C. purpurea sensu lato in Norway, 2) characterize the associated indole alkaloid profiles, and 3) explore relationships between genetics, alkaloid chemistry and ecology. Approximately 600 sclerotia from 14 different grass species were subjected to various analyses including DNA sequencing and HPLC-MS. Molecular results, supported by chemical and ecological data, revealed one new genetic group (G4) in addition to two of the three known; G1 (C. purpurea sensu stricto) and G2 (C. humidiphila). G3 (C. spartinae) was not found. G4, which was apparently con-specific with the recently described C. arundinis sp. nov, was predominantly found in very wet habitats on Molinia caerulea and infrequently in saline habitats on Leymus arenarius. Its indole-diterpene profile resembled G2, while its ergot alkaloid profile differed from G2 in high amounts of ergosedmam. In contrast to G1, indole-diterpenes were consistently present in G2 and G4. Our study supports and complements the newly proposed species delimitation of the C. purpurea complex, but challenges some species characteristics including host spectrum, habitat preferences and sclerotial floating ability.
Collapse
Affiliation(s)
- Mariell Negård
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.
| | - Silvio Uhlig
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
- Department of the Chemical and Biological Working Environment, National Institute of Occupational Health, P.O. Box 8149 Dep, 0033 Oslo, Norway.
| | - Håvard Kauserud
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.
| | - Tom Andersen
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.
| | - Klaus Høiland
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.
| | - Trude Vrålstad
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
- Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway.
| |
Collapse
|
3
|
Charlton ND, Craven KD, Afkhami ME, Hall BA, Ghimire SR, Young CA. Interspecific hybridization and bioactive alkaloid variation increases diversity in endophytic Epichloë species of Bromus laevipes. FEMS Microbiol Ecol 2014; 90:276-89. [PMID: 25065688 DOI: 10.1111/1574-6941.12393] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/27/2014] [Accepted: 07/18/2014] [Indexed: 11/29/2022] Open
Abstract
Studying geographic variation of microbial mutualists, especially variation in traits related to benefits they provide their host, is critical for understanding how these associations impact key ecological processes. In this study, we investigate the phylogenetic population structure of Epichloë species within Bromus laevipes, a native cool-season bunchgrass found predominantly in California. Phylogenetic classification supported inference of three distinct Epichloë taxa, of which one was nonhybrid and two were interspecific hybrids. Inheritance of mating-type idiomorphs revealed that at least one of the hybrid species arose from independent hybridization events. We further investigated the geographic variation of endophyte-encoded alkaloid genes, which is often associated with key benefits of natural enemy protection for the host. Marker diversity at the ergot alkaloid, loline, indole-diterpene, and peramine loci revealed four alkaloid genotypes across the three identified Epichloë species. Predicted chemotypes were tested using endophyte-infected plant material that represented each endophyte genotype, and 11 of the 13 predicted alkaloids were confirmed. This multifaceted approach combining phylogenetic, genotypic, and chemotypic analyses allowed us to reconstruct the diverse evolutionary histories of Epichloë species present within B. laevipes and highlight the complex and dynamic processes underlying these grass-endophyte symbioses.
Collapse
Affiliation(s)
- Nikki D Charlton
- Forage Improvement Division, The Samuel Roberts Noble Foundation, Ardmore, OK, USA
| | | | | | | | | | | |
Collapse
|
4
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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.
Collapse
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:
| |
Collapse
|