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Sullivan TJ, Roberts H, Bultman TL. Genetic Covariation Between the Vertically Transmitted Endophyte Epichloë canadensis and Its Host Canada Wildrye. MICROBIAL ECOLOGY 2023; 86:1686-1695. [PMID: 36725749 DOI: 10.1007/s00248-022-02166-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 12/26/2022] [Indexed: 06/18/2023]
Abstract
Symbiotic mutualisms are thought to be stabilized by correlations between the interacting genotypes which may be strengthened via vertical transmission and/or reduced genetic variability within each species. Vertical transmission, however, may weaken interactions over time as the endosymbionts would acquire mutations that could not be purged. Additionally, temporal variation in a conditional mutualism could create genetic variation and increased variation in the interaction outcome. In this study, we assessed genetic variation in both members of a symbiosis, the endosymbiotic fungal endophyte Epichloë canadensis and its grass host Canada wildrye (Elymus canadensis). Both species exhibited comparable levels of diversity, mostly within populations rather than between. There were significant differences between populations, although not in the same pattern for the two species, and the differences were not correlated with geographic distance for either species. Interindividual genetic distance matrices for the two species were significantly correlated, although all combinations of discriminant analysis of principle components (DAPC) defined multilocus genotype groups were found suggesting that strict genotype matching is not necessary. Variation in interaction outcome is common in grass/endophyte interactions, and our results suggest that the accumulation of mutations overtime combined with temporal variation in selection pressures increasing genetic variation in the symbiosis may be the cause.
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Affiliation(s)
- T J Sullivan
- School of Sciences, Indiana University Kokomo, 2300 S. Washington St, Kokomo, IN, 46902, USA.
| | - Holly Roberts
- School of Sciences, Indiana University Kokomo, 2300 S. Washington St, Kokomo, IN, 46902, USA
| | - Thomas L Bultman
- Department of Biology, Hope College, 35 E. 12th St., Holland, MI, 49423, USA
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Laihonen M, Rainio K, Birge T, Saikkonen K, Helander M, Fuchs B. Root biomass and cumulative yield increase with mowing height in Festuca pratensis irrespective of Epichloë symbiosis. Sci Rep 2022; 12:21556. [PMID: 36513732 PMCID: PMC9748035 DOI: 10.1038/s41598-022-25972-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022] Open
Abstract
Increasing agricultural soil carbon sequestration without compromising the productivity of the land is a key challenge in global climate change mitigation. The carbon mitigation potential of grass-based agriculture is particularly high because grasslands represent 70% of the world's agricultural area. The root systems of grasses transfer large amounts of carbon to below-ground storage, and the carbon allocation to the roots is dependent on the grasses' photosynthesizing shoot biomass. In a common-garden experiment, Festuca pratensis was used as a model species to study how mowing and weed control practices of perennial cool-season fodder grasses affect total yield and root biomass. Additionally, grass-associated Epichloë endophytes and soil residual glyphosate were tested for their effect on the total yield and root biomass alone or in interaction with mowing. The results demonstrate that elevating the cutting height increases both cumulative yield and root biomass in F. pratensis. Endophyte symbiosis increased the total yield, while glyphosate-based herbicide residues in the soil decreased the root biomass, which indicates a reduction of soil bound carbon sequestration. The findings demonstrate that carbon sequestration and yield quantities on farmed grasslands may significantly be improved by optimizing strategies for the use of plant protection products and adjustment of mowing intensity.
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Affiliation(s)
- Miika Laihonen
- Biodiversity Unit, University of Turku, 20014, Turku, Finland
| | - Kalle Rainio
- Biodiversity Unit, University of Turku, 20014, Turku, Finland
| | - Traci Birge
- Biodiversity Unit, University of Turku, 20014, Turku, Finland
| | - Kari Saikkonen
- Biodiversity Unit, University of Turku, 20014, Turku, Finland
| | - Marjo Helander
- Department of Biology, University of Turku, 20014, Turku, Finland
| | - Benjamin Fuchs
- Biodiversity Unit, University of Turku, 20014, Turku, Finland.
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3
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Denison RF, Muller KE. An evolutionary perspective on increasing net benefits to crops from symbiotic microbes. Evol Appl 2022; 15:1490-1504. [PMID: 36330301 PMCID: PMC9624085 DOI: 10.1111/eva.13384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/05/2022] [Accepted: 04/06/2022] [Indexed: 11/30/2022] Open
Abstract
Plant-imposed, fitness-reducing sanctions against less-beneficial symbionts have been documented for rhizobia, mycorrhizal fungi, and fig wasps. Although most of our examples are for rhizobia, we argue that the evolutionary persistence of mutualism in any symbiosis would require such sanctions, if there are multiple symbiont genotypes per host plant. We therefore discuss methods that could be used to develop and assess crops with stricter sanctions. These include methods to screen strains for greater mutualism as resources to identify crop genotypes that impose stronger selection for mutualism. Single-strain experiments that measure costs as well as benefits have shown that diversion of resources by rhizobia can reduce nitrogen-fixation efficiency (N per C) and that some legumes can increase this efficiency by manipulating their symbionts. Plants in the field always host multiple strains with possible synergistic interactions, so benefits from different strains might best be compared by regressing plant growth or yield on each strain's abundance in a mixture. However, results from this approach have not yet been published. To measure legacy effects of stronger sanctions on future crops, single-genotype test crops could be planted in a field that recently had replicated plots with different genotypes of the sanction-imposing crop. Enhancing agricultural benefits from symbiosis may require accepting tradeoffs that constrained past natural selection, including tradeoffs between current and future benefits.
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Affiliation(s)
- R. Ford Denison
- Ecology, Evolution, & BehaviorUniversity of MinnesotaSaint PaulMinnesotaUSA
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Li N, Xu D, Huang RH, Zheng JY, Liu YY, Hu BS, Gu YQ, Du Q. A New Source of Diterpene Lactones From Andrographis paniculata (Burm. f.) Nees—Two Endophytic Fungi of Colletotrichum sp. With Antibacterial and Antioxidant Activities. Front Microbiol 2022; 13:819770. [PMID: 35295309 PMCID: PMC8918950 DOI: 10.3389/fmicb.2022.819770] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/18/2022] [Indexed: 02/06/2023] Open
Abstract
Endophytic fungi of medicinal plants are abundant, and their metabolites often have antioxidant, antibacterial, and antitumor effects and can produce secondary metabolites identical or similar to those of their hosts, which can mitigate the problem of insufficient supply of medicinal plants. In this study, we screened endophytic fungi for strains that produce the same diterpene lactones as Andrographis paniculata based on their biological activity. Firstly, the dominant group of endophytic fungi of Andrographis paniculata was screened and pathogenicity was studied using Koch’s rule. Secondly, DPPH, ABTS, OH, PTIO radical scavenging, and FRAP assays were used to detect the antioxidant activity of the extracellular extracts of the strains, and total phenol and total flavonoid contents of the strains with high antioxidant capacity were determined. S. aureus, B. subtilis, E. coli, and P. aeruginosa were used to determine the antibacterial activity of the mycelial extracts of the strains. Finally, the secondary metabolites of the mycelial extracts of the strains were examined by high-performance liquid chromatography. The results showed that 32 strains of Andrographis paniculata were relatively isolated > 70% and non-pathogenic. Extracellular extracts of strains AP-1 and AP-4 showed vigorous antioxidant activity, and AP-4, AP-12, AP-47, and AP-48 showed antibacterial activity against four strains of bacteria. The HPLC results indicated that the mycelial extracts of AP-4 and AP-12 contained diterpene lactones. The two endophytic fungi were recognized as Colletotrichum sp. The study successfully obtained diterpene lactones from the endophytic fungus of Andrographis paniculata and confirmed the feasibility of using endophytic fungal strains to produce active substances consistent with the host. It was also useful for exploring endophytic fungi and medicinal plants. The relationship provides theoretical guidance.
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Xu W, Li M, Lin W, Nan Z, Tian P. Effects of Epichloë sinensis Endophyte and Host Ecotype on Physiology of Festuca sinensis under Different Soil Moisture Conditions. PLANTS (BASEL, SWITZERLAND) 2021; 10:1649. [PMID: 34451694 PMCID: PMC8402098 DOI: 10.3390/plants10081649] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/04/2021] [Accepted: 08/07/2021] [Indexed: 11/16/2022]
Abstract
This study explored the effects of the Epichloë sinensis endophyte on growth, photosynthesis, ionic content (K+ and Ca2+), phytohormones (abscisic acid-ABA, cytokinin-CTK, indolE-3-acetic acid-IAA, and gibberellin-GA), and elements-C, N, P (in the shoot and root) in two ecotypes of Festuca sinensis (ecotypes 111 and 141) under different soil water conditions (35% and 65% relative saturation moisture content (RSMC)). The results showed that 35% RSMC inhibited the plants' growth, and compared with 65% RSMC, there was a significant (p < 0.05) decrease in the growth and photosynthesis indices, the contents of CTK and GA, Ca2+ concentration, and the contents of C, N, and P (in both the aboveground and underground parts) under 35% RSMC. E. sinensis had beneficial effects on host growth and stress tolerance. Under both 35% and 65% RSMC, the presence of E. sinensis significantly (p < 0.05) increased host plant height, tiller number, root length, root volume, shoot dry weight, chlorophyll content, and the rate of photosynthesis of both ecotypes. Furthermore, the shoot C, N, and P contents in plants infected with E. sinensis (E+) from the two ecotypes, under both conditions of RSMC, were significantly (p < 0.05) higher than those in corresponding plants that were not infected with E. sinensis (E-). Under 35% RSMC, the contents of ABA, K+, Ca2+, and root P contents in E+ plants were significantly (p < 0.05) higher than those in corresponding E- plants in both ecotypes. However, under 65% RSMC, root C, N, and P contents in E+ plants of ecotype 111 and 141 were significantly (p < 0.05) higher than those in corresponding E- plants. In addition, the host ecotype also had effects on host growth and stress tolerance; the growth and photosynthetic indices of ecotype 141 were significantly (p < 0.05) higher than those of ecotype 111 under 35% RSMC, which suggested that ecotype 141 is more competitive than ecotype 111 under water deficiency conditions. These findings suggest that the endophyte improved the host plant resistance to water deficiency by maintaining the growth of the plant, improving photosynthesis, accumulating K+ and Ca2+, promoting nutrient absorption, and adjusting the metabolism of plant hormones.
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Affiliation(s)
- Wenbo Xu
- State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; (W.X.); (M.L.); (W.L.); (Z.N.)
| | - Miaomiao Li
- State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; (W.X.); (M.L.); (W.L.); (Z.N.)
| | - Weihu Lin
- State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; (W.X.); (M.L.); (W.L.); (Z.N.)
- Institute of Rural Development, Gansu Provincial Academy of Social Sciences, Lanzhou 730071, China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; (W.X.); (M.L.); (W.L.); (Z.N.)
| | - Pei Tian
- State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; (W.X.); (M.L.); (W.L.); (Z.N.)
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Bao G, Song M, Wang Y, Saikkonen K, Li C. Does Epichloë Endophyte Enhance Host Tolerance to Root Hemiparasite? MICROBIAL ECOLOGY 2021; 82:35-48. [PMID: 32086543 DOI: 10.1007/s00248-020-01496-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
Epichloë endophytes have been shown to be mutualistic symbionts of cool-season grasses under most environmental conditions. Although pairwise interactions between hemiparasites and their hosts are heavily affected by host-associated symbiotic microorganisms, little attention has been paid to the effects of microbe-plant interactions, particularly endophytic symbiosis, in studies examining the effects of parasitic plants on host performance. In this study, we performed a greenhouse experiment to examine the effects of hereditary Epichloë endophyte symbiosis on the growth of two host grasses (Stipa purpurea and Elymus tangutorum) in the presence or absence of a facultative root hemiparasite (Pedicularis kansuensis Maxim). We observed parasitism of both hosts by P. kansuensis: when grown with a host plant, the hemiparasite decreased the performance of the host while improving its own biomass and survival rate of the hemiparasite. Parasitized endophyte-infected S. purpurea plants had higher biomass, tillers, root:shoot ratio, and photosynthetic parameters and a lower number of functional haustoria than the endophyte-free S. purpurea conspecifics. By contrast, parasitized endophyte-infected E. tangutorum had a lower biomass, root:shoot ratio, and photosynthetic parameters and a higher number of haustoria and functional haustoria than their endophyte-free counterparts. Our results reveal that the interactions between the endophytes and the host grasses are context dependent and that plant-plant interactions can strongly affect their mutualistic interactions. Endophytes originating from S. purpurea alleviate the host biomass reduction by P. kansuensis and growth depression in the hemiparasite. These findings shed new light on using grass-endophyte symbionts as biocontrol methods for the effective and sustainable management of this weedy hemiparasite.
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Affiliation(s)
- Gensheng Bao
- Academy of Animal and Veterinary Medicine, Qinghai University, Xining, 810016, China
- College of Pastoral Agriculture Science and Technology, Lanzhou University, 730020, Lanzhou, China
| | - Meiling Song
- Academy of Animal and Veterinary Medicine, Qinghai University, Xining, 810016, China
| | - Yuqin Wang
- Academy of Animal and Veterinary Medicine, Qinghai University, Xining, 810016, China
| | - Kari Saikkonen
- Biodiversity Unit, University of Turku, 20014, Turku, Finland
| | - Chunjie Li
- State Key Laboratory of Grassland Agro-Ecosystems, Lanzhou University, Lanzhou, 730020, China.
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Franco MF, Colabelli MN, Echeverría MDLM, Ispizúa VN. Epichloë endophyte modifies the foliar anatomy of Lolium multiflorum Lam. Symbiosis 2020. [DOI: 10.1007/s13199-020-00702-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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8
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Impact of endophyte inoculation on the morphological identity of cultivars of Lolium perenne (L) and Festuca arundinacea (Schreb.). Sci Rep 2020; 10:7729. [PMID: 32382099 PMCID: PMC7205862 DOI: 10.1038/s41598-020-64474-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/09/2020] [Indexed: 11/08/2022] Open
Abstract
Grass endophytes have been shown to confer enhanced environmental resilience to symbiont cultivars with reports of modified growth. If inoculating with an endophyte (E+) made an accession morphologically distinct from its registered endophyte free (E−) accession, there could be protection and ownership issues for testing authorities and breeders. This study investigated if, in official Plant Breeders Rights (PBR) field trials, the morphological characteristics of E+and E− accessions of perennial ryegrass and tall fescue cultivars were sufficiently modified to designate them as mutually distinct and also distinct from their definitive accessions (Def), held by the testing authorities. Testing perennial ryegrass on 17 characters at 2 sites generated 48,960 observations and for tall fescue on 9 characters at 1 site, 12,960 observations (each for 3 accessions of 4 cultivars × 60 plants × 2 growing cycles). Distinctness required a p < 0.01 difference in a single character from the combined over years analysis (COYD). A few significant differences were recorded between E− and E+accessions. Cultivar Carn E+ was smaller than Carn E− for Infloresence Length (p < 0.01) in both years but COYD analysis (p < 0.05) was insufficient to declare distinctiveness. Overall, the number of observed differences between E−/E+ accessions was less or similar to the number expected purely by chance. In contrast, comparisons between Def and E− or E+ accessions showed a number of significant differences that were substantially more numerous than expected by chance. These results showed no conclusive evidence of endophyte inclusion creating false PBR distinctions but unexpectedly, several E− and E+ accessions were distinguished from their official definitive stock.
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Liu H, Wu M, Liu J, Qu Y, Gao Y, Ren A. Tripartite Interactions Between Endophytic Fungi, Arbuscular Mycorrhizal Fungi, and Leymus chinensis. MICROBIAL ECOLOGY 2020; 79:98-109. [PMID: 31177395 DOI: 10.1007/s00248-019-01394-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
Grasses often establish multiple simultaneous symbiotic associations with endophytic fungi and arbuscular mycorrhizal fungi (AMF). Many studies have examined pair-wise interactions between plants and endophytic fungi or between plants and AMF, overlooking the interplays among multiple endosymbionts and their combined impacts on hosts. Here, we examined both the way in which each symbiont affects the other symbionts and the tripartite interactions between leaf endophytic fungi, AMF, and Leymus chinensis. As for AMF, different species (Glomus etunicatum, GE; Glomus mosseae, GM; Glomus claroideum, GC; and Glomus intraradices, GI) and AMF richness (no AMF, single AMF taxa, double AMF mixtures, triple AMF mixtures, and all four together) were considered. Our results showed that significant interactions were observed between endophytes and AMF, with endophytes interacting antagonistically with GM but synergistically with GI. No definitive interactions were observed between the endophytes and GE or GC. Additionally, the concentration of endophytes in the leaf sheath was positively correlated with the concentration of AMF in the roots under low AMF richness. The shoot biomass of L. chinensis was positively related to both endophyte concentration and AMF concentration, with only endophytes contributing to shoot biomass more than AMF. Endophytes and AMF increased shoot growth by contributing to phosphorus uptake. The interactive effects of endophytes and AMF on host growth were affected by the identity of AMF species. The beneficial effect of the endophytes decreased in response to GM but increased in response to GI. However, no influences were observed with other GC and GE. In addition, endophyte presence can alter the response of host plants to AMF richness. When leaf endophytes were absent, shoot biomass increased with higher AMF richness, only the influence of AMF species identity outweighed that of AMF richness. However, when leaf endophytes were present, no significant association was observed between AMF richness and shoot biomass. AMF species identity rather than AMF richness promoted shoot growth. The results of this study demonstrate that the outcomes of interspecific symbiotic interactions are very complex and vary with partner identity such that the effects of simultaneous symbioses cannot be generalized and highlight the need for studies to evaluate fitness response of all three species, as the interactive effects may not be the same for each partner.
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Affiliation(s)
- Hui Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Man Wu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Jinming Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yaobing Qu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yubao Gao
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Anzhi Ren
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China.
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Hajji-Hedfi L, M’Hamdi-Boughalleb N, Horrigue-Raouani N. Fungal diversity in rhizosphere of root-knot nematode infected tomatoes in Tunisia. Symbiosis 2019. [DOI: 10.1007/s13199-019-00639-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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11
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Growth and physiological responses of perennial ryegrass to an AMF and an Epichloë endophyte under different soil water contents. Symbiosis 2019. [DOI: 10.1007/s13199-019-00633-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Munzi S, Cruz C, Corrêa A. When the exception becomes the rule: An integrative approach to symbiosis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 672:855-861. [PMID: 30978547 DOI: 10.1016/j.scitotenv.2019.04.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 06/09/2023]
Abstract
Symbiosis, mainly due to the advances in -omics technology and to the microbiome revolution, is being increasingly acknowledged as fundamental to explain any aspect of life existence. Previously considered an exception, a peculiar characteristic of few systems like lichens, corals and mycorrhizas, symbiosis is nowadays recognized as the rule, with the microbiome being part of all living entities and systems. However, our knowledge of the ecological meaning and functioning of many symbiotic systems is still limited. Here, we discuss a new, integrative approach based on current findings that looks at commonalities among symbiotic systems to produce theoretical models and conceptual knowledge that would allow a more efficient exploitation of symbiosis-based biotechnologies. The microbiome recruitment and assemblage processes are indicated as one of the potential targets where a holistic approach could bring advantages. Finally, we reflect on the potential socio-economic and environmental consequences of a symbiotic view of the world, where co-dependence is the matrix of life.
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Affiliation(s)
- Silvana Munzi
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Cristina Cruz
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Ana Corrêa
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
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Shymanovich T, Faeth SH. Environmental factors affect the distribution of two Epichloë fungal endophyte species inhabiting a common host grove bluegrass ( Poa alsodes). Ecol Evol 2019; 9:6624-6642. [PMID: 31236248 PMCID: PMC6580270 DOI: 10.1002/ece3.5241] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 01/24/2023] Open
Abstract
AIM The endophyte Epichloë alsodes, with known insecticidal properties, is found in a majority of Poa alsodes populations across a latitudinal gradient from North Carolina to New York. A second endophyte, E. schardlii var. pennsylvanica, with known insect-deterring effects, is limited to a few populations in Pennsylvania. We explored whether such disparate differences in distributions could be explained by selection from biotic and abiotic environmental factors. LOCATION Along the Appalachian Mountains from North Carolina to New York, USA. TAXON Fungi. METHODS Studied correlations of infection frequencies with abiotic and biotic environmental factors. Checked endophyte vertical transmission rates and effects on overwintering survival. With artificial inoculations for two host populations with two isolates per endophyte species, tested endophyte-host compatibility. Studied effects of isolates on host performances in greenhouse experiment with four water-nutrients treatments. RESULTS Correlation analysis revealed positive associations of E. alsodes frequency with July Max temperatures, July precipitation, and soil nitrogen and phosphorous and negative associations with insect damage and soil magnesium and potassium. Plants infected with E. alsodes had increased overwintering survival compared to plants infected with E. schardlii or uninfected (E-) plants. Artificial inoculations indicated that E. alsodes had better compatibility with a variety of host genotypes than did E. schardlii. The experiment with reciprocally inoculated plants grown under different treatments revealed a complexity of interactions among hosts, endophyte species, isolate within species, host plant origin, and environmental factors. Neither of the endophyte species increased plant biomass, but some of the isolates within each species had other effects on plant growth such as increased root:shoot ratio, number of tillers, and changes in plant height that might affect host fitness. MAIN CONCLUSION In the absence of clear and consistent effects of the endophytes on host growth, the differences in endophyte-mediated protection against herbivores may be the key factor determining distribution differences of the two endophyte species.
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Affiliation(s)
- Tatsiana Shymanovich
- Biology DepartmentUniversity of North Carolina at GreensboroGreensboroNorth Carolina
| | - Stanley H. Faeth
- Biology DepartmentUniversity of North Carolina at GreensboroGreensboroNorth Carolina
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Qian X, Li H, Wang Y, Wu B, Wu M, Chen L, Li X, Zhang Y, Wang X, Shi M, Zheng Y, Guo L, Zhang D. Leaf and Root Endospheres Harbor Lower Fungal Diversity and Less Complex Fungal Co-occurrence Patterns Than Rhizosphere. Front Microbiol 2019; 10:1015. [PMID: 31143169 PMCID: PMC6521803 DOI: 10.3389/fmicb.2019.01015] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/24/2019] [Indexed: 12/21/2022] Open
Abstract
Plant-associated microbiomes are key determinants of host-plant fitness, productivity, and function. However, compared to bacterial community, we still lack fundamental knowledge concerning the variation in the fungal microbiome at the plant niche level. In this study, we quantified the fungal communities in the rhizosphere soil, as well as leaf and root endosphere compartments of a subtropical island shrub, Mussaenda kwangtungensis, using high-throughput DNA sequencing. We found that fungal microbiomes varied significantly across different plant compartments. Rhizosphere soil exhibited the highest level of fungal diversity, whereas the lowest level was found in the leaf endosphere. Further, the fungal communities inhabiting the root endosphere shared a greater proportion of fungal operational taxonomic units (OTUs) with rhizosphere communities than with leaf fungal endophyte communities, despite significant separation in community structure between the two belowground compartments. The fungal co-occurrence networks in the three compartments of M. kwangtungensis showed scale-free features and non-random co-occurrence patterns and matched the topological properties of small-world and evidently modular structure. Additionally, the rhizosphere network was more complex and showed higher centrality and connectedness than the leaf and root endosphere networks. Overall, our findings provide comprehensive insights into the structural variability, niche differentiation, and co-occurrence patterns in the plant associated fungal microbiome.
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Affiliation(s)
- Xin Qian
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hanzhou Li
- Biomarker Technologies Corporation, Beijing, China
| | - Yonglong Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Binwei Wu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Mingsong Wu
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Liang Chen
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xingchun Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ying Zhang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiangping Wang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Miaomiao Shi
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yong Zheng
- Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou, China
| | - Liangdong Guo
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Dianxiang Zhang
- Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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15
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Leinonen PH, Helander M, Vázquez-de-Aldana BR, Zabalgogeazcoa I, Saikkonen K. Local adaptation in natural European host grass populations with asymmetric symbiosis. PLoS One 2019; 14:e0215510. [PMID: 30995278 PMCID: PMC6469795 DOI: 10.1371/journal.pone.0215510] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/04/2019] [Indexed: 11/18/2022] Open
Abstract
Recent work on microbiomes is revealing the wealth and importance of plant-microbe interactions. Microbial symbionts are proposed to have profound effects on fitness of their host plants and vice versa, especially when their fitness is tightly linked. Here we studied local adaptation of host plants and possible fitness contribution of such symbiosis in the context of abiotic environmental factors. We conducted a four-way multi-year reciprocal transplant experiment with natural populations of the perennial grass Festuca rubra s.l. from northern and southern Finland, Faroe Islands and Spain. We included F. rubra with and without transmitted symbiotic fungus Epichloë that is vertically transmitted via host seed. We found local adaptation across the European range, as evidenced by higher host fitness of the local geographic origin compared with nonlocals at three of the four studied sites, suggesting that selection pressures are driving evolution in different directions. Abiotic factors did not result in strong fitness effects related to Epichloë symbiosis, indicating that other factors such as herbivory are more likely to contribute to fitness differences between plants naturally occurring with or without Epichloë. Nevertheless, in the case of asymmetric symbiosis that is obligatory for the symbiont, abiotic conditions that affect performance of the host, may also cause selective pressure for the symbiont.
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Affiliation(s)
- Päivi H. Leinonen
- Natural Resources Institute Finland (Luke), Helsinki, Finland
- * E-mail:
| | - Marjo Helander
- Department of Biology and Biodiversity Unit, University of Turku, Turku, Finland
| | | | | | - Kari Saikkonen
- Natural Resources Institute Finland (Luke), Turku, Finland
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16
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Forest Tree Microbiomes and Associated Fungal Endophytes: Functional Roles and Impact on Forest Health. FORESTS 2019. [DOI: 10.3390/f10010042] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Terrestrial plants including forest trees are generally known to live in close association with microbial organisms. The inherent features of this close association can be commensalism, parasitism or mutualism. The term “microbiota” has been used to describe this ecological community of plant-associated pathogenic, mutualistic, endophytic and commensal microorganisms. Many of these microbiota inhabiting forest trees could have a potential impact on the health of, and disease progression in, forest biomes. Comparatively, studies on forest tree microbiomes and their roles in mutualism and disease lag far behind parallel work on crop and human microbiome projects. Very recently, our understanding of plant and tree microbiomes has been enriched due to novel technological advances using metabarcoding, metagenomics, metatranscriptomics and metaproteomics approaches. In addition, the availability of massive DNA databases (e.g., NCBI (USA), EMBL (Europe), DDBJ (Japan), UNITE (Estonia)) as well as powerful computational and bioinformatics tools has helped to facilitate data mining by researchers across diverse disciplines. Available data demonstrate that plant phyllosphere bacterial communities are dominated by members of only a few phyla (Proteobacteria, Actinobacteria, Bacteroidetes). In bulk forest soil, the dominant fungal group is Basidiomycota, whereas Ascomycota is the most prevalent group within plant tissues. The current challenge, however, is how to harness and link the acquired knowledge on microbiomes for translational forest management. Among tree-associated microorganisms, endophytic fungal biota are attracting a lot of attention for their beneficial health- and growth-promoting effects, and were preferentially discussed in this review.
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17
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Abstract
Endophytic fungi are an important component that colonizes in healthy tissues of living plants and can be readily isolated from any microbial or plant growth medium. They act as reservoirs of novel bioactive secondary metabolites, such as alkaloids, phenolic acids, quinones, steroids, saponins, tannins, and terpenoids that serve as a potential candidate for antimicrobial, anti-insect, anticancer and many more properties. Their huge diversity and particular habituation, they can provide a good area for research in the field of making new medicines and novel drug-like molecules. Because of the impact of endophytes on host plant by enhancing their growth or increasing their fitness, also making them tolerant to abiotic and biotic stresses and holding the secondary metabolites, endophytes are gaining attention as a subject for research. This review aims to comprehend the contribution and uses of endophytes and relationships between endophytic fungi and their host medicinal plants.
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18
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Tall S, Meyling NV. Probiotics for Plants? Growth Promotion by the Entomopathogenic Fungus Beauveria bassiana Depends on Nutrient Availability. MICROBIAL ECOLOGY 2018; 76:1002-1008. [PMID: 29594431 DOI: 10.1007/s00248-018-1180-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Cultivation of crops requires nutrient supplements which are costly and impact the environment. Furthermore, global demands for increased crop production call for sustainable solutions to increase yield and utilize resources such as nutrients more effectively. Some entomopathogenic fungi are able to promote plant growth, but studies over such effects have been conducted under optimal conditions where nutrients are abundantly available. We studied the effects of Beauveria bassiana (strain GHA) seed treatment on the growth of maize (Zea mays) at high and low nutrient conditions during 6 weeks in greenhouse. As expected, B. bassiana seed treatment increased plant growth, but only at high nutrient conditions. In contrast, the seed treatment did not benefit plant growth at low nutrient conditions where the fungus potentially constituted a sink and tended to reduce plant growth. The occurrence of endophytic B. bassiana in experimental plant tissues was evaluated by PCR after 6 weeks, but B. bassiana was not documented in any of the above-ground plant tissues indicating that the fungus-plant interaction was independent of endophytic establishment. Our results suggest that B. bassiana seed treatment could be used as a growth promoter of maize when nutrients are abundantly available, while the fungus does not provide any growth benefits when nutrients are scarce.
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Affiliation(s)
- Susanna Tall
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Nicolai V Meyling
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark.
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19
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Liu H, Chen W, Wu M, Wu R, Zhou Y, Gao Y, Ren A. Arbuscular mycorrhizal fungus inoculation reduces the drought-resistance advantage of endophyte-infected versus endophyte-free Leymus chinensis. MYCORRHIZA 2017; 27:791-799. [PMID: 28799077 DOI: 10.1007/s00572-017-0794-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/31/2017] [Indexed: 06/07/2023]
Abstract
Grasses can be infected simultaneously by endophytic fungi and arbuscular mycorrhizal (AM) fungi. In this study, we tested the hypothesis that endophyte-associated drought resistance of a native grass was affected by an AM fungus. In a greenhouse experiment, we compared the performance of endophyte-infected (EI) and endophyte-free (EF) Leymus chinensis, a dominant species native to the Inner Mongolia steppe, under altered water and AM fungus availability. The results showed that endophyte infection significantly increased drought resistance of the host grass, but the beneficial effects were reduced by AM fungus inoculation. In the mycorrhizal-non-inoculated (MF) treatment, EI plants accumulated significantly more biomass, had greater proline and total phenolic concentration, and lower malondialdehyde concentration than EF plants. In the mycorrhizal-inoculation (MI) treatment, however, no significant difference occurred in either growth or physiological characters measured between EI and EF plants. AM fungus inoculation enhanced drought resistance of EF plants but had no significant effect on drought resistance of EI plants, thus AM fungus inoculation reduced the difference between EI and EF plants. Our findings highlight the importance of interactions among multiple microorganisms for plant performance under drought stress.
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Affiliation(s)
- Hui Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Wei Chen
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Man Wu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Rihan Wu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yong Zhou
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yubao Gao
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Anzhi Ren
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China.
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20
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Iannone L, Vignale M, Pinget A, Re A, Mc Cargo P, Novas M. Seed-transmitted Epichloë sp. endophyte alleviates the negative effects of head smut of grasses (Ustilago bullata) on Bromus auleticus. FUNGAL ECOL 2017. [DOI: 10.1016/j.funeco.2017.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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21
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22
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23
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Higgins KL, Coley PD, Kursar TA, Arnold AE. Culturing and direct PCR suggest prevalent host generalism among diverse fungal endophytes of tropical forest grasses. Mycologia 2017; 103:247-60. [DOI: 10.3852/09-158] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Thomas A. Kursar
- Department of Biology, University of Utah, Salt Lake City, Utah 84112
| | - A. Elizabeth Arnold
- Division of Plant Pathology and Microbiology, School of Plant Sciences, University of Arizona, Tucson, Arizona 85721
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24
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Faeth SH, Oberhofer M, Saari S, Haskins KE, Shymanovich T. Does hybridization of endophytic symbionts in a native grass increase fitness in resource-limited environments? Ecology 2017; 98:138-149. [PMID: 28052394 DOI: 10.1002/ecy.1626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/03/2016] [Accepted: 10/13/2016] [Indexed: 11/10/2022]
Abstract
Hybridization is common among plants, animals and microbes. However, the ecological consequences of hybridization for microbes are far less understood than for plants and animals. For symbiotic Epichloë fungi, hybridization is widespread and may augment the well-known benefits of the endophytes to their grass hosts, especially in stressful environments. We tested the hybrid fitness hypothesis (HFH) that hybrid endophytes enhance fitness in stressful environments relative to non-hybrid endophytes. In a long-term field experiment, we monitored growth and reproduction of hybrid-infected (H+), non-hybrid infected (NH+), naturally endophyte free (E-) plants and those plants from which the endophyte had been experimentally removed (H- and NH-) in resource-rich and resource-poor environments. Infection by both endophyte species enhanced growth and reproduction. H+ plants outperformed NH+ plants in terms of growth by the end of the experiment, supporting HFH. However, H+ plants only outperformed NH+ plants in the resource-rich treatment, contrary to HFH. Plant genotypes associated with each endophyte species had strong effects on growth and reproduction. Our results provide some support the HFH hypothesis but not based upon adaptation to stressful environments. Our results reinforce the notion of a complex interplay between endophyte and plant genotype and environmental factors that determine fitness of the symbiotum.
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Affiliation(s)
- Stanley H Faeth
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, 27402, USA
| | - Martina Oberhofer
- Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Susanna Saari
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Kristin E Haskins
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, 86011, USA
| | - Tatsiana Shymanovich
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, 27402, USA
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25
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Tong J, Miaowen C, Juhui J, Jinxian L, Baofeng C. Endophytic fungi and soil microbial community characteristics over different years of phytoremediation in a copper tailings dam of Shanxi, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 574:881-888. [PMID: 27665448 DOI: 10.1016/j.scitotenv.2016.09.161] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/18/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
We conducted a survey of native grass species infected by endophytic fungi in a copper tailings dam over progressive years of phytoremediation. We investigated how endophytic fungi, soil microbial community structure and soil physiochemical properties and enzymatic activity varied in responses to heavy metal pollution over different stages of phytoremediation. endophyte infection frequency increased with years of phytoremediation. Rates of endophyte infection varied among different natural grass species in each sub-dam. Soil carbon content and soil enzymatic activity gradually increased through the years of phytoremediation. endophyte infection rates of Bothriochloa ischaemum and Festuca rubra were positively related to levels of cadmium (Cd) pollution levels, and fungal endophytes associated with Imperata cylindrical and Elymus dahuricus developed tolerance to lead (Pb). The structure and relative abundance of bacterial communities varied little over years of phytoremediation, but there was a pronounced variation in soil fungi types. Leotiomycetes were the dominant class of resident fungi during the initial phytoremediation period, but Pezizomycetes gradually became dominant as the phytoremediation period progressed. Fungal endophytes in native grasses as well as soil fungi and soil bacteria play different ecological roles during phytoremediation processes.
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Affiliation(s)
- Jia Tong
- Institute of Loess Plateau, Shanxi University, Wucheng Road 92, Taiyuan, Shanxi 030006, China.
| | - Cao Miaowen
- Institute of Loess Plateau, Shanxi University, Wucheng Road 92, Taiyuan, Shanxi 030006, China
| | - Jing Juhui
- Institute of Biotechnology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Liu Jinxian
- Institute of Loess Plateau, Shanxi University, Wucheng Road 92, Taiyuan, Shanxi 030006, China
| | - Chai Baofeng
- Institute of Loess Plateau, Shanxi University, Wucheng Road 92, Taiyuan, Shanxi 030006, China
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26
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Li X, Zhou Y, Mace W, Qin J, Liu H, Chen W, Ren A, Gao Y. Endophyte species influence the biomass production of the native grass Achnatherum sibiricum (L.) Keng under high nitrogen availability. Ecol Evol 2016; 6:8595-8606. [PMID: 28031810 PMCID: PMC5167029 DOI: 10.1002/ece3.2566] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 09/19/2016] [Accepted: 09/30/2016] [Indexed: 11/19/2022] Open
Abstract
Research on the interaction of endophytes and native grasses normally takes infection status into account, but less often considers the species of endophyte involved in the interaction. Here, we examined the effect of endophyte infection, endophyte species, nitrogen availability, and plant maternal genotype on the performance of a wild grass, Achnatherum sibiricum. Six different Epichloë-infected maternal lines of A. sibiricum were used in the study; three lines harbored Epichloë gansuensis (Eg), while three lines harbored Epichloë sibirica (Es). These endophytes are vertically transmitted, while Eg also occasionally produces stromata on host tillers. We experimentally removed the endophyte from some ramets of the six lines, with the infected (E+) and uninfected (E-) plants grown under varying levels of nitrogen availability. Eg hosts produced more aboveground biomass than Es hosts only under high nitrogen supply. Endophyte species did not show any influence on the maximum net photosynthetic rate (Pmax), photosynthetic nitrogen use efficiency, or total phenolics of A. sibiricum under all nitrogen conditions. However, the plant maternal genotype did influence the Pmax and shoot biomass of A. sibiricum. Our results show that endophyte species influenced the shoot biomass of A. sibiricum, and this effect was dependent on nitrogen supply. As with most coevolutionary interactions, A. sibiricum that harbored Eg and Es may show pronounced geographic variation in natural habitats with increased nitrogen deposition. In addition, stroma-bearing endophyte (Eg) provides positive effects (e.g., higher biomass production) to A. sibiricum plants during the vegetative growth stage.
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Affiliation(s)
- Xia Li
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
- Present address: College of Life SciencesHebei UniversityBaodingChina
| | - Yong Zhou
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
| | - Wade Mace
- AgResearch LtdGrasslands Research CentrePalmerston NorthNew Zealand
| | - Junhua Qin
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
| | - Hui Liu
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
| | - Wei Chen
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
| | - Anzhi Ren
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
| | - Yubao Gao
- Department of Plant Biology and EcologyCollege of Life SciencesNankai UniversityTianjinChina
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27
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Bibian AJ, Rudgers JA, Miller TEX. The Role of Host Demographic Storage in the Ecological Dynamics of Heritable Symbionts. Am Nat 2016; 188:446-59. [PMID: 27622878 DOI: 10.1086/687965] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Heritable symbioses are widespread and ecologically important. Many host organisms have complex life cycles that include diverse opportunities for symbionts to affect their host and be lost during development. Yet, existing theory takes a simplified view of host demography. Here, we generalize symbiosis theory to understand how demographic "storage" in the form of dormant or prereproductive life stages can modify symbiosis dynamics. Using grass-endophyte symbioses as context, we developed models to contrast the role of the seed bank (a storage stage) against the reproductive stage in symbiont persistence and prevalence. We find that the seed bank is as important as or more important than the reproductive stage in driving symbiont dynamics, as long as passage through the seed bank is obligate. Flexible entry to the seed bank substantially weakens its influence on symbiont persistence but can modify prevalence in counterintuitive ways. Our models identify a role for legacy effects, where hosts that lose symbionts retain their demographic influence. The retention of benefits via legacy effects can reduce symbiont prevalence and even cause prevalence to decline with increasing benefits to hosts because symbiont-free hosts carry those benefits. Our results resolve connections between individual-level host-symbiont interactions and population-level patterns, providing guidance for empirical studies.
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28
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Jia T, Oberhofer M, Shymanovich T, Faeth SH. Effects of Hybrid and Non-hybrid Epichloë Endophytes and Their Associated Host Genotypes on the Response of a Native Grass to Varying Environments. MICROBIAL ECOLOGY 2016; 72:185-196. [PMID: 26909796 DOI: 10.1007/s00248-016-0743-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 02/15/2016] [Indexed: 06/05/2023]
Abstract
Asexual Epichloë endophytes are prevalent in cool season grasses, and many are of hybrid origin. Hybridization of asexual endophytes is thought to provide a rapid influx of genetic variation that may be adaptive to endophyte-host grass symbiota in stressful environments. For Arizona fescue (Festuca arizonica), hybrid symbiota are commonly found in resource-poor environments, whereas non-hybrid symbiota are more common in resource-rich environments. There have been very few experimental tests where infection, hybrid and non-hybrid status, and plant genotype have been controlled to tease apart their effects on host phenotype and fitness in different environments. We conducted a greenhouse experiment where hybrid (H) and non-hybrid (NH) endophytes were inoculated into plant genotypes that were originally uninfected (E-) or once infected with either the H or NH endophytes. Nine endophyte and plant genotypic group combinations were grown under low and high water and nutrient treatments. Inoculation with the resident H endophyte enhanced growth and altered allocation to roots and shoots, but these effects were greatest in resource-rich environments, contrary to expectations. We found no evidence of co-adaptation between endophyte species and their associated host genotypes. However, naturally E- plants performed better when inoculated with the hybrid endophyte, suggesting these plants were derived from H infected lineages. Our results show complex interactions between endophyte species of hybrid and non-hybrid origin with their host plant genotypes and environmental factors.
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Affiliation(s)
- Tong Jia
- Institute of Loess Plateau, Shanxi University, Taiyuan, 030006, China.
| | - Martina Oberhofer
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
| | - Tatsiana Shymanovich
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
| | - Stanley H Faeth
- Department of Biology, University of North Carolina Greensboro, 321 McIver Street, Greensboro, NC, 27412, USA
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29
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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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30
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Effects of simultaneous infections of endophytic fungi and arbuscular mycorrhizal fungi on the growth of their shared host grass Achnatherum sibiricum under varying N and P supply. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2015.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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31
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Vincent JB, Weiblen GD, May G. Host associations and beta diversity of fungal endophyte communities in New Guinea rainforest trees. Mol Ecol 2016; 25:825-41. [PMID: 26661903 DOI: 10.1111/mec.13510] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 11/21/2015] [Accepted: 11/30/2015] [Indexed: 01/09/2023]
Abstract
Processes shaping the distribution of foliar fungal endophyte species remain poorly understood. Despite increasing evidence that these cryptic fungal symbionts of plants mediate interactions with pathogens and herbivores, there remain basic questions regarding the extent to which dispersal limitation and host specificity might shape fungal endophyte community composition in rainforests. To assess the relative importance of spatial pattern and host specificity, we isolated fungi from a sample of mapped trees in lowland Papua New Guinea. Sequences of the internal transcribed spacer (ITS) region were obtained for 2079 fungal endophytes from three sites and clustered into molecular operational taxonomic units (MOTUs) at 95% similarity. Multivariate analyses suggest that host affinity plays a significant role in structuring endophyte community composition whereas there was no evidence of endophyte spatial pattern at the scale of tens to hundreds of metres. Differences in endophyte communities between sampled trees were weakly correlated with variation in foliar traits but not with tree species relatedness. The dominance of relatively few generalist endophytes and the presence of a large number of rare MOTUs was a consistent observation at three sites separated by hundreds of kilometres and regional turnover was low. Host specificity appears to play a relatively weak but more important role than dispersal limitation in shaping the distribution of fungal endophyte communities in New Guinea forests. Our results suggest that in the absence of strong ecological gradients and host turnover, beta diversity of endophyte communities could be low in large areas of contiguous forest.
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Affiliation(s)
- J B Vincent
- Plant Biological Sciences Graduate Program, 250 Biological Sciences Center, University of Minnesota, 1445 Gortner Avenue, St. Paul, MN, 55108, USA
| | - G D Weiblen
- Bell Museum and Department of Plant Biology, 250 Biological Sciences Center, University of Minnesota, 1445 Gortner Avenue, St. Paul, MN, 55108, USA
| | - G May
- Department of Ecology, Evolution and Behavior, University of Minnesota, 100 Ecology Building, 1987 Upper Buford Circle, Falcon Heights, MN, 55108, USA
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32
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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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Rozpądek P, Wężowicz K, Nosek M, Ważny R, Tokarz K, Lembicz M, Miszalski Z, Turnau K. The fungal endophyte Epichloë typhina improves photosynthesis efficiency of its host orchard grass (Dactylis glomerata). PLANTA 2015; 242:1025-35. [PMID: 26059605 PMCID: PMC4560772 DOI: 10.1007/s00425-015-2337-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/21/2015] [Indexed: 05/23/2023]
Abstract
MAIN CONCLUSION According to the results presented in this paper the fungal endophyte Epichloë typhina significantly improves the growth, PSII photochemistry and C assimilation efficiency of its host Dactylis glomerata. In this paper, we present a comprehensive study of the impact of the endophytic fungi Epichloë typhina on its plant hosts' photosynthesis apparatus. Chlorophyll a fluorescence, gas exchange, immuno-blotting and spectrophotometric measurements were employed to assess photosynthetic performance, changes in pigment content and mechanisms associated with light harvesting, carbon assimilation and energy distribution in Dactylis glomerata colonized with Epichloë typhina. According to the results presented in this study, colonization of D. glomerata results in improved photosynthesis efficiency. Additionally, we propose a new mechanism allowing plants to cope with the withdrawal of a significant fraction of its energy resources by the endophytic fungi. The abundance of LHCI, LHCII proteins as well as chlorophyll b was significantly higher in E+ plants. Malate export out of the chloroplast was shown to be increased in colonized plants. To our knowledge, we are the first to report this phenomenon. Epichloë colonization improved PSII photochemistry and C assimilation efficiency. Elevated energy demands of E+ D. glomerata plants are met by increasing the rate of carbon assimilation and PSII photochemistry.
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Affiliation(s)
- Piotr Rozpądek
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland,
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McGranahan DA, Burgdorf R, Kirkman KP. Epichloae infection in a native South African grass, Festuca costata Nees. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:914-921. [PMID: 25619128 DOI: 10.1111/plb.12307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 01/16/2015] [Indexed: 06/04/2023]
Abstract
Fungal endophytes have been documented in almost all terrestrial plant groups. Although the endophyte infection syndrome in agronomic cultivars is well studied, relatively little work addresses questions of spatial ecology and fire effects on epichloae endophyte infection in native grasses, and none, to our knowledge, in sub-Saharan Africa. We sampled seven populations of the native Festuca costata Nees along the spline of the Drakensberg range in South Africa at several spatial scales, including both recently burned and unburned stands. We tested epichloae presence and prevalence with immunoblot assays, PCR and genetic sequencing. We found epichloae endophytes were present and prevalent (38-98% infection rates depending on location). Variation in infection rates occurred primarily among locations, but also among bunches. There was little evidence that endophyte infection rates varied with fire. Novel evidence of epichloae infection of a native Festuca in South Africa opens the door to several new research questions, from the phylogenetic relationship between epichloae of sub-Saharan Africa and other continents to the ecological advantages or disadvantages that endophytes confer upon their hosts, especially in a fire-prone ecosystem vulnerable to global environmental change.
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Affiliation(s)
- D A McGranahan
- School of Natural Resource Sciences - Range Science, North Dakota State University, Fargo, ND, USA
| | - R Burgdorf
- Plant Pathology, School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - K P Kirkman
- Grassland Science, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Endophyte-mediated disease resistance in wild populations of perennial ryegrass (Lolium perenne). FUNGAL ECOL 2015. [DOI: 10.1016/j.funeco.2015.01.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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37
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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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Vandegrift R, Blaser W, Campos-Cerda F, Heneghan AF, Carroll GC, Roy BA. Mixed fitness effects of grass endophytes modulate impact of enemy release and rapid evolution in an invasive grass. Biol Invasions 2014. [DOI: 10.1007/s10530-014-0791-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Canty MJ, Fogarty U, Sheridan MK, Ensley SM, Schrunk DE, More SJ. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland? Ir Vet J 2014; 67:21. [PMID: 25295161 PMCID: PMC4186922 DOI: 10.1186/2046-0481-67-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 08/06/2014] [Indexed: 11/14/2022] Open
Abstract
Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as ‘ergot alkaloid intoxication’. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of a small number of equine and bovine farms where poor animal health and performance had been reported. Additionally, in some circumstances changes to the diet, where animals were fed primarily herbage, were sufficient to reverse adverse effects. Pending additional information, these results suggest that Irish farm advisors and veterinarians should be aware of the potential adverse role on animal health and performance of ergot alkaloids from perennial ryegrass infected with endophytic fungi.
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Affiliation(s)
- Mary J Canty
- Centre for Veterinary Epidemiology and Risk Analysis (CVERA), Veterinary Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland ; Department of Agriculture, Food and the Marine, Agriculture House, Kildare St, Dublin 2, Ireland
| | - Ursula Fogarty
- Irish Equine Centre, Johnstown, Naas, Co. Kildare, Ireland
| | - Michael K Sheridan
- Department of Agriculture, Food and the Marine, Agriculture House, Kildare St, Dublin 2, Ireland
| | - Steve M Ensley
- College of Veterinary Medicine, Iowa State University, Ames, IA 2011, USA
| | - Dwayne E Schrunk
- College of Veterinary Medicine, Iowa State University, Ames, IA 2011, USA
| | - Simon J More
- Centre for Veterinary Epidemiology and Risk Analysis (CVERA), Veterinary Sciences Centre, University College Dublin, Belfield, Dublin 4, Ireland
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Tadych M, Bergen MS, White JF. Epichloë spp. associated with grasses: new insights on life cycles, dissemination and evolution. Mycologia 2014; 106:181-201. [PMID: 24877257 DOI: 10.3852/106.2.181] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epichloë species with their asexual states are specialized fungi associated with cool-season grasses. they grow endophytically in tissues of aerial parts of host plants to form systemic and mostly asymptomatic associations. Their life cycles may involve vertical transmission through host seeds and/or horizontal transmission from one plant to other plants of the same species through fungal propagules. Vertical transmission has been well studied, but comparatively little research has been done on horizontal dissemination. The goal of this review is to provide new insights on modes of dissemination of systemic grass endophytes. The review addresses recent progress in research on (i) the process of growth of Epichloë endophytes in the host plant tissues, (ii) the types and development of reproductive structures of the endophyte, (iii) the role of the reproductive structures in endophyte dissemination and host plant infection processes and (iv) some ecological and evolutionary implications of their modes of dissemination. Research in the Epichloë grass endophytes has accelerated in the past 25 y and has demonstrated the enormous complexity in endophyte-grass symbioses. There still remain large gaps in our understanding of the role and functions of these fungi in agricultural systems and understanding the functions, ecology and evolution of these endophytes in natural grass populations.
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Fungal endophyte mediated occurrence of seminiferous and pseudoviviparous panicles in Festuca rubra. FUNGAL DIVERS 2014. [DOI: 10.1007/s13225-014-0290-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Fukui S. Evolution of symbiosis with resource allocation from fecundity to survival. Naturwissenschaften 2014; 101:437-46. [PMID: 24744057 PMCID: PMC4012156 DOI: 10.1007/s00114-014-1175-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 04/05/2014] [Accepted: 04/06/2014] [Indexed: 11/30/2022]
Abstract
Symbiosis is one of the most fundamental relationships between or among organisms and includes parasitism (which has negative effects on the fitness of the interacting partner), commensalism (no effect), and mutualism (positive effects). The effects of these interactions are usually assumed to influence a single component of a species’ fitness, either survival or fecundity, even though in reality the interaction can simultaneously affect both of these components. I used a dual lattice model to investigate the process of evolution of mutualistic symbiosis in the presence of interactive effects on both survival and fecundity. I demonstrate that a positive effect on survival and a negative effect on fecundity are key to the establishment of mutualism. Furthermore, both the parasitic and the mutualistic behaviour must carry large costs for mutualism to evolve. This helps develop a new understanding of symbiosis as a function of resource allocation, in which resources are shifted from fecundity to survival. The simultaneous establishment of mutualism from parasitism never occurs in two species, but can do so in one of the species as long as the partner still behaves parasitically. This suggests that one of the altruistic behaviours in a mutualistic unit consisting of two species must originate as a parasitic behaviour.
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Affiliation(s)
- Shin Fukui
- Center for Ecological Research, Kyoto University, 2-509-3 Hirano, Otsu, Shiga, 520-2113, Japan,
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Delaye L, García-Guzmán G, Heil M. Endophytes versus biotrophic and necrotrophic pathogens—are fungal lifestyles evolutionarily stable traits? FUNGAL DIVERS 2013. [DOI: 10.1007/s13225-013-0240-y] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Arabidopsis thaliana model system reveals a continuum of responses to root endophyte colonization. Fungal Biol 2013; 117:250-60. [DOI: 10.1016/j.funbio.2013.02.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Revised: 01/18/2013] [Accepted: 02/01/2013] [Indexed: 11/20/2022]
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45
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Zhu MJ, Ren AZ, Wen W, Gao YB. Diversity and taxonomy of endophytes fromLeymus chinensisin the Inner Mongolia steppe of China. FEMS Microbiol Lett 2013; 340:135-45. [DOI: 10.1111/1574-6968.12083] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 01/07/2013] [Accepted: 01/09/2013] [Indexed: 11/28/2022] Open
Affiliation(s)
- Min-Jie Zhu
- Department of Plant Biology and Ecology; College of Life Science; Nankai University; Tianjin; China
| | - An-Zhi Ren
- Department of Plant Biology and Ecology; College of Life Science; Nankai University; Tianjin; China
| | - Wei Wen
- Department of Plant Biology and Ecology; College of Life Science; Nankai University; Tianjin; China
| | - Yu-Bao Gao
- Department of Plant Biology and Ecology; College of Life Science; Nankai University; Tianjin; China
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Saari S, Faeth SH. Hybridization of Neotyphodium endophytes enhances competitive ability of the host grass. THE NEW PHYTOLOGIST 2012; 195:231-236. [PMID: 22489964 DOI: 10.1111/j.1469-8137.2012.04140.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
• Associations with microbial symbionts may lead to niche differentiation of their host. Vertically transmitted Neotyphodium endophytes of grasses often hybridize in nature. Infection by these hybrid symbionts may result in different host-plant phenotypes from those caused as a result of infection by nonhybrid symbionts. Observations of wild Arizona fescue (Festuca arizonica) populations show that hybrid Neotyphodium-infected (H+) grasses dominate in resource-poor environments, whereas nonhybrid endophyte-infected (NH+) grasses dominate in environments with more resources. We studied the hypothesis that hybridization of endophytes increases stress tolerance of the host. • To test whether hybridization of Neotyphodium affects performance and competitive abilities of the host depending on resources, we conducted a glasshouse experiment where competition, nutrients and watering were manipulated. • H+ plants had greater wet biomass than NH+ and endophyte-free plants, when grown in competition, but only in low-water and low-nutrient treatments. By contrast, NH+ plants did not perform better than H+ or endophyte-free plants regardless of the treatment combination. • Our results suggest that hybridization of symbiotic Neotyphodium endophytes may increase competitive potential of the host in stressful environments and that this hybridization may be underlying niche expansion of Arizona fescue in the environments with low resources.
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Affiliation(s)
- S Saari
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC 27402, USA.
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Gundel PE, Helander M, Casas C, Hamilton CE, Faeth SH, Saikkonen K. Neotyphodium fungal endophyte in tall fescue (Schedonorus phoenix): a comparison of three Northern European wild populations and the cultivar Kentucky-31. FUNGAL DIVERS 2012. [DOI: 10.1007/s13225-012-0173-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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48
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Fungal grass endophytes and arthropod communities: lessons from plant defence theory and multitrophic interactions. FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2011.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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49
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Endophyte-mediated adjustments in host morphology and physiology and effects on host fitness traits in grasses. FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2011.05.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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Bultman TL, Aguilera A, Sullivan TJ. Influence of fungal isolates infecting tall fescue on multitrophic interactions. FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2011.06.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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