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Bastías DA, Ueno AC, Gundel PE. Global Change Factors Influence Plant-Epichloë Associations. J Fungi (Basel) 2023; 9:jof9040446. [PMID: 37108902 PMCID: PMC10145611 DOI: 10.3390/jof9040446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 04/08/2023] Open
Abstract
There is an increasing interest in determining the influence of global change on plant–microorganism interactions. We review the results of experiments that evaluated the effects of the global change factors carbon dioxide, ozone, temperature, drought, flooding, and salinity on plant symbioses with beneficial Epichloë endophytes. The factors affected the performance of both plants and endophytes as well as the frequency of plants symbiotic with the fungus. Elevated carbon dioxide levels and low temperatures differentially influenced the growth of plants and endophytes, which could compromise the symbioses. Furthermore, we summarise the plant stage in which the effects of the factors were quantified (vegetative, reproductive, or progeny). The factors ozone and drought were studied at all plant stages, but flooding and carbon dioxide were studied in just a few of them. While only studied in response to ozone and drought, evidence showed that the effects of these factors on symbiotic plants persisted trans-generationally. We also identified the putative mechanisms that would explain the effects of the factors on plant–endophyte associations. These mechanisms included the increased contents of reactive oxygen species and defence-related phytohormones, reduced photosynthesis, and altered levels of plant primary metabolites. Finally, we describe the counteracting mechanisms by which endophytes would mitigate the detrimental effects of the factors on plants. In presence of the factors, endophytes increased the contents of antioxidants, reduced the levels of defence-related phytohormones, and enhanced the plant uptake of nutrients and photosynthesis levels. Knowledge gaps regarding the effects of global change on plant–endophyte associations were identified and discussed.
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Affiliation(s)
- Daniel A. Bastías
- AgResearch Limited, Grasslands Research Centre, Palmerston North 4442, New Zealand
| | - Andrea C. Ueno
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3480094, Chile
- Instituto de Investigación Interdisciplinaria (I3), Universidad de Talca, Campus Talca, Talca 3480094, Chile
| | - Pedro E. Gundel
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3480094, Chile
- Facultad de Agronomía, IFEVA, CONICET, Universidad de Buenos Aires, Buenos Aires C1417DSE, Argentina
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Bubica Bustos LM, Ueno AC, Biganzoli F, Card SD, Mace WJ, Martínez-Ghersa MA, Gundel PE. Can Aphid Herbivory Induce Intergenerational Effects of Endophyte-conferred Resistance in Grasses? J Chem Ecol 2022; 48:867-881. [PMID: 36372818 DOI: 10.1007/s10886-022-01390-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/20/2022] [Accepted: 10/23/2022] [Indexed: 11/15/2022]
Abstract
Plants have evolved mechanisms to survive herbivory. One such mechanism is the induction of defences upon attack that can operate intergenerationally. Cool-season grasses (sub-family Pooideae) obtain defences via symbiosis with vertically transmitted fungal endophytes (genus Epichloë) and can also show inducible responses. However, it is unknown whether these herbivore-induced responses can have intergenerational effects. We hypothesized that herbivory by aphids on maternal plants induces the intergenerational accumulation of endophyte-derived defensive alkaloids and resistance intensification in the progeny. We subjected mother plants symbiotic or not with Epichloë occultans, a species known for its production of anti-insect alkaloids known as lolines, to the aphid Rhopalosiphum padi. Then, we evaluated the progeny of these plants in terms of loline alkaloid concentration, resistance level (through herbivore performance), and shoot biomass. Herbivory on mother plants did not increase the concentration of lolines in seeds but it tended to affect loline concentration in progeny plants. There was an overall herbivore-induced intergenerational effect increasing the endophyte-conferred defence and resistance. Symbiotic plants were more resistant to aphids and had higher shoot biomass than their non-symbiotic counterparts. Since maternal herbivory did not affect the loline concentrations in seeds, the greater resistance of the progeny could have resulted from an inherited mechanism of epigenetic regulation. It would be interesting to elucidate the origin of this regulation since it could come from the host or the fungal symbiont. Thus, endophyte-driven differential fitness between symbiotic and non-symbiotic plants might be higher as generations pass on in presence of herbivores.
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Affiliation(s)
| | - Andrea C Ueno
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Campus Lircay, Talca, Chile
| | - Fernando Biganzoli
- Departamento de Métodos Cuantitativos y Sistemas de Información, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Stuart D Card
- Resilient Agriculture, Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | - Wade J Mace
- Resilient Agriculture, Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | | | - Pedro E Gundel
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Campus Lircay, Talca, Chile.
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Yang Z, Jin Y, Hou F, Bowatte S. Soil microbial and chemical responses to foliar Epichloë fungal infection in Lolium perenne, Hordeum brevisubulatum and Achnatherum inebrians. FUNGAL ECOL 2021. [DOI: 10.1016/j.funeco.2021.101091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Patchett A, Newman JA. Comparison of Plant Metabolites in Root Exudates of Lolium perenne Infected with Different Strains of the Fungal Endophyte Epichloë festucae var. lolii. J Fungi (Basel) 2021; 7:jof7020148. [PMID: 33670493 PMCID: PMC7922862 DOI: 10.3390/jof7020148] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/07/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022] Open
Abstract
Lolium perenne infected with the fungal endophyte Epichloë festucae var. lolii have specific, endophyte strain-dependent, chemical phenotypes in their above-ground tissues. Differences in these chemical phenotypes have been largely associated with classes of fungal-derived alkaloids which protect the plant against many insect pests. However, the use of new methodologies, such as various omic techniques, has demonstrated that many other chemical changes occur in both primary and secondary metabolites. Few studies have investigated changes in plant metabolites exiting the plant in the form of root exudates. As root exudates play an essential role in the acquisition of nutrients, microbial associations, and defense in the below-ground environment, it is of interest to understand how plant root exudate chemistry is influenced by the presence of strains of a fungal endophyte. In this study, we tested the influence of four strains of E. festucae var. lolii (E+ (also known as Lp19), AR1, AR37, NEA2), and uninfected controls (E-), on L. perenne growth and the composition of root exudate metabolites. Root exudates present in the hydroponic water were assessed by untargeted metabolomics using Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) liquid chromatography-mass spectrometry (LC-MS). The NEA2 endophyte strain resulted in the greatest plant biomass and the lowest endophyte concentration. We found 84 metabolites that were differentially expressed in at least one of the endophyte treatments compared to E- plants. Two compounds were strongly associated with one endophyte treatment, one in AR37 (m/z 135.0546 RT 1.17), and one in E+ (m/z 517.1987 RT 9.26). These results provide evidence for important changes in L. perenne physiology in the presence of different fungal endophyte strains. Further research should aim to connect changes in root exudate chemical composition with soil ecosystem processes.
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Affiliation(s)
- Aurora Patchett
- Department of Earth Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Jonathan A. Newman
- Department of Biology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada
- Correspondence:
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Geddes-McAlister J, Sukumaran A, Patchett A, Hager HA, Dale JCM, Roloson JL, Prudhomme N, Bolton K, Muselius B, Powers J, Newman JA. Examining the Impacts of CO 2 Concentration and Genetic Compatibility on Perennial Ryegrass- Epichloë festucae var lolii Interactions. J Fungi (Basel) 2020; 6:jof6040360. [PMID: 33322591 PMCID: PMC7770580 DOI: 10.3390/jof6040360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022] Open
Abstract
Perennial ryegrass (Lolium perenne) is the most cultivated cool-season grass worldwide with crucial roles in carbon fixation, turfgrass applications, and fodder for livestock. Lolium perenne forms a mutualism with the strictly vertically transmitted fungal endophyte, Epichloë festucae var lolii. The fungus produces alkaloids that protect the grass from herbivory, as well as conferring protection from drought and nutrient stress. The rising concentration of atmospheric CO2, a proximate cause of climatic change, is known to have many direct and indirect effects on plant growth. There is keen interest in how the nature of this plant-fungal interaction will change with climate change. Lolium perenne is an obligately outcrossing species, meaning that the genetic profile of the host is constantly being reshuffled. Meanwhile, the fungus is asexual implying both a relatively constant genetic profile and the potential for incompatible grass-fungus pairings. In this study, we used a single cultivar, "Alto", of L. perenne. Each plant was infected with one of four strains of the endophyte: AR1, AR37, NEA2, and Lp19 (the "common strain"). We outcrossed the Alto mothers with pollen from a number of individuals from different ryegrass cultivars to create more genetic diversity in the hosts. We collected seed such that we had replicate maternal half-sib families. Seed from each family was randomly allocated into the two levels of the CO2 treatment, 400 and 800 ppm. Elevated CO2 resulted in an c. 18% increase in plant biomass. AR37 produced higher fungal concentrations than other strains; NEA2 produced the lowest fungal concentrations. We did not find evidence of genetic incompatibility between the host plants and the fungal strains. We conducted untargeted metabolomics and quantitative proteomics to investigate the grass-fungus interactions between and within family and treatment groups. We identified a number of changes in both the proteome and metabalome. Taken together, our data set provides new understanding into the intricacy of the interaction between endophyte and host from multiple molecular levels and suggests opportunity to promote plant robustness and survivability in rising CO2 environmental conditions through application of bioprotective epichloid strains.
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Affiliation(s)
- Jennifer Geddes-McAlister
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
- Mass Spectrometry Facility—Advanced Analysis Centre, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence: (J.G.-M.); (J.A.N.)
| | - Arjun Sukumaran
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Aurora Patchett
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Heather A. Hager
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jenna C. M. Dale
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jennifer L. Roloson
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Nicholas Prudhomme
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Kim Bolton
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Benjamin Muselius
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.S.); (N.P.); (B.M.)
| | - Jacqueline Powers
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
| | - Jonathan A. Newman
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada; (A.P.); (H.A.H.); (J.C.M.D.); (J.L.R.); (K.B.); (J.P.)
- Correspondence: (J.G.-M.); (J.A.N.)
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Sun K, Zhang W, Yuan J, Song SL, Wu H, Tang MJ, Xu FJ, Xie XG, Dai CC. Nitrogen fertilizer-regulated plant-fungi interaction is related to root invertase-induced hexose generation. FEMS Microbiol Ecol 2020; 96:5869223. [PMID: 32643762 DOI: 10.1093/femsec/fiaa139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/08/2020] [Indexed: 11/13/2022] Open
Abstract
The mechanisms underlying nitrogen (N)-regulated plant-fungi interactions are not well understood. N application modulates plant carbohydrate (C) sinks and is involved in the overall plant-fungal association. We hypothesized that N regulates plant-fungi interactions by influencing the carbohydrate metabolism. The mutualistic fungus Phomopsis liquidambaris was found to prioritize host hexose resources through in vitro culture assays and in planta inoculation. Rice-Ph. liquidambaris systems were exposed to N gradients ranging from N-deficient to N-abundant conditions to study whether and how the sugar composition was involved in the dynamics of N-mediated fungal colonization. We found that root soluble acid invertases were activated, resulting in increased hexose fluxes in inoculated roots. These fluxes positively influenced fungal colonization, especially under N-deficient conditions. Further experiments manipulating the carbohydrate composition and root invertase activity through sugar feeding, chemical treatments and the use of different soil types revealed that the external disturbance of root invertase could reduce endophytic colonization and eliminate endophyte-induced host benefits under N-deficient conditions. Collectively, these results suggest that the activation of root invertase is related to N deficiency-enhanced endophytic colonization via increased hexose generation. Certain combinations of farmland ecosystems with suitable N inputs could be implemented to maximize the benefits of plant-fungi associations.
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Affiliation(s)
- Kai Sun
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Wei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Jie Yuan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Shi-Li Song
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Hao Wu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Meng-Jun Tang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Fang-Ji Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Xing-Guang Xie
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
| | - Chuan-Chao Dai
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Sciences, Nanjing Normal University, Jiangsu Province, China
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Wu LS, Dong WG, Si JP, Liu JJ, Zhu YQ. Endophytic fungi, host genotype, and their interaction influence the growth and production of key chemical components of Dendrobium catenatum. Fungal Biol 2020; 124:864-876. [PMID: 32948274 DOI: 10.1016/j.funbio.2020.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/22/2020] [Accepted: 07/05/2020] [Indexed: 12/22/2022]
Abstract
To examine how host plant genotype, endophytic fungal species, and their interaction may affect growth and key chemical content and composition in an important orchid species, we assessed four Dendrobium catenatum cultivars co-cultured with three fungi previously isolated from D. catenatum. Fungal endophytes (Tulasnella sp., Leptosphaeria microscopica, and Guignardia sp.) specifically affected the growth and chemical composition of the four cultivars. Fungal infection significantly increased certain growth traits, especially mid-stem thickness, stem biomass, stem polysaccharide and ethanol-soluble extractive content, and leaf flavonoid and phenol content. Presence or abundance of some key chemical components was also altered by fungal treatment. These increases and alterations were highly dependent on the host genotype. The findings of this study contribute to our understanding of Dendrobium and endophytic fungi interactions, and provide vital information for improving the development and use of endophytic fungi in D. catenatum breeding.
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Affiliation(s)
- Ling-Shang Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, PR China
| | - Wei-Guo Dong
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, PR China
| | - Jin-Ping Si
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, PR China.
| | - Jing-Jing Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, PR China
| | - Yu-Qiu Zhu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Lin'an, Hangzhou, 311300, PR China
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Freitas PP, Hampton JG, Rolston MP, Glare TR, Miller PP, Card SD. A Tale of Two Grass Species: Temperature Affects the Symbiosis of a Mutualistic Epichloë Endophyte in Both Tall Fescue and Perennial Ryegrass. FRONTIERS IN PLANT SCIENCE 2020; 11:530. [PMID: 32457777 PMCID: PMC7225326 DOI: 10.3389/fpls.2020.00530] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/07/2020] [Indexed: 05/12/2023]
Abstract
Many cool-season grasses form permanent, mutualistic symbioses with asexual Epichloë endophytes. These fungal symbionts often perform a protective role within the association as many strains produce secondary metabolites that deter certain mammalian and invertebrate herbivores. Although initially a serious issue for agriculture, due to mammalian toxins that manifested in major animal health issues, selected strains that provide abiotic stress protection to plants with minimal ill effects to livestock are now commercialized and routinely used to enhance pasture performance in many farming systems. These fungal endophytes and their grass hosts have coevolved over millions of years, and it is now generally accepted that most taxonomic groupings of Epichloë are confined to forming compatible associations (i.e., symptomless associations) with related grass genera within a tribe. The most desired compounds associated with Epichloë festucae var. lolii, an endophyte species associated with perennial ryegrass, are peramine and epoxy-janthitrems. No other major secondary metabolites with invertebrate bioactivity have been identified within this association. However, other agriculturally beneficial compounds, such as lolines, have been discovered in related endophyte species that form associations with fescue grasses. A rationale therefore existed to develop novel grass-endophyte associations between loline-producing endophytes originally isolated from tall fescue with elite cultivars of perennial ryegrass to achieve a wider spectrum of insect bioactivity. A suitable loline-producing endophyte strain of Epichloë sp. FaTG-3 was selected and inoculated into perennial ryegrass. We hypothesed that endophyte transmission frequency, endophyte mycelial biomass and endophyte-derived alkaloid production would differ between the original tall fescue host and the artificial association. Consistent with our hypothesis, our data strongly suggest that plant species significantly affected the plant-endophyte association. This effect became more apparent for transmission frequency and endophyte biomass as the plants matured. Overall, the viable endophyte infection frequency was greater in the tall fescue host than in perennial ryegrass, at all sampling dates. Additionally, temperature was found to be a significant factor affecting endophyte transmission frequency, endophyte mycelial biomass and alkaloid production. Implications for the development of novel grass-endophyte associations are discussed.
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Affiliation(s)
| | - John G. Hampton
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - M. Phil. Rolston
- Forage Science, AgResearch Limited, Lincoln Research Centre, Lincoln, New Zealand
- The Foundation for Arable Research, Christchurch, New Zealand
| | - Travis R. Glare
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Poppy P. Miller
- Knowledge and Analytics, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Stuart D. Card
- Forage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
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Hewitt KG, Mace WJ, McKenzie CM, Matthew C, Popay AJ. Fungal Alkaloid Occurrence in Endophyte-Infected Perennial Ryegrass during Seedling Establishment. J Chem Ecol 2020; 46:410-421. [PMID: 32125583 DOI: 10.1007/s10886-020-01162-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/06/2020] [Accepted: 02/18/2020] [Indexed: 10/24/2022]
Abstract
The symbiotic Epichloë festucae var. lolii endophyte produces alkaloids which can provide its host grass, perennial ryegrass (Lolium perenne L), with a selective advantage in both natural and agricultural managed ecosystems. This study focuses on understanding the alkaloid concentrations that occur in endophyte-infected perennial ryegrass during the early establishment phase. In a glasshouse experiment fungal alkaloid concentrations (peramine, lolitrem B, ergovaline, and epoxy-janthitrems) were measured in perennial ryegrass seedlings infected with E. festucae var. lolii proprietary strains AR1, AR37, NEA2, and NZ common toxic for 69 days after sowing. The endophyte becomes metabolically active, starting alkaloid production, as early as 6 days after sowing. Alkaloid concentrations peaked in 8- to 10- day-old seedlings due to a seedling growth slowdown. This study provides data showing that the loss of insect protection in endophyte-infected seedlings is linked to a reduction in chemical defence after seed-stored, maternally synthesised alkaloids are diluted by seedling dry matter accumulation.
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Affiliation(s)
- Katrin G Hewitt
- The New Zealand Institute for Plant and Food Research Limited (Plant & Food Research), Physiological Chemistry, Ruakura, Private Bag 3230, Waikato Mail Centre, Hamilton, 3240, New Zealand. .,AgResearch Ltd, Biocontrol & Biosecurity, Grasslands Research Centre, Private Bag 11008, Palmerston North, 4442, New Zealand.
| | - Wade J Mace
- AgResearch Ltd, Forage Improvement, Grasslands Research Centre, Private Bag 11008, Palmerston North, 4442, New Zealand
| | - Catherine M McKenzie
- Plant & Food Research, Data Science, 412 No 1 Road, RD 2, Te Puke, 3182, New Zealand
| | - Cory Matthew
- School of Agriculture and Environment, Massey University, Private Bag 11-222, Palmerston North, 4442, New Zealand
| | - Alison J Popay
- AgResearch Ltd, Biocontrol & Biosecurity, Ruakura Research Private Bag 3123, Hamilton, 3240, New Zealand
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Novel bioassay to assess antibiotic effects of fungal endophytes on aphids. PLoS One 2020; 15:e0228813. [PMID: 32040957 PMCID: PMC7010463 DOI: 10.1371/journal.pone.0228813] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 01/23/2020] [Indexed: 11/19/2022] Open
Abstract
Perennial ryegrass is an important feed base for the dairy and livestock industries around the world. It is often infected with mutualistic fungal endophytes that confer protection to the plant against biotic and abiotic stresses. Bioassays that test their antibiotic effect on invertebrates are varied and range from excised leaves to whole plants. The aim of this study was to design and validate a "high-throughput" in-planta bioassay using 7-day-old seedlings confined in small cups, allowing for rapid assessments of aphid life history to be made while maintaining high replication and treatment numbers. Antibiosis was evaluated on the foliar and the root aphid species; Diuraphis noxia (Mordvilko) and Aploneura lentisci (Passerini) feeding on a range of perennial ryegrass-Epichloë festucae var. Lolii endophyte symbiota. As expected, both D. noxia and A. lentisci reared on endophyte-infected plants showed negatively affected life history traits by comparison to non-infected plants. Both species exhibited the highest mortality at the nymphal stage with an average total mortality across all endophyte treatments of 91% and 89% for D. noxia and A. lentisci respectively. Fecundity decreased significantly on all endophyte treatments with an average total reduction of 18% and 16% for D. noxia and A. lentisci respectively by comparison to non-infected plants. Overall, the bioassay proved to be a rapid method of evaluating the insecticidal activity of perennial ryegrass-endophyte symbiota on aphids (nymph mortality could be assessed in as little as 24 and 48 hours for D. noxia and A. lentisci respectively). This rapid and simple approach can be used to benchmark novel grass-endophyte symbiota on a range of aphid species that feed on leaves of plants, however we would caution that it may not be suitable for the assessment of root-feeding aphids, as this species exhibited relatively high mortality on the control as well.
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Cagnano G, Roulund N, Jensen CS, Forte FP, Asp T, Leuchtmann A. Large Scale Screening of Epichloë Endophytes Infecting Schedonorus pratensis and Other Forage Grasses Reveals a Relation Between Microsatellite-Based Haplotypes and Loline Alkaloid Levels. FRONTIERS IN PLANT SCIENCE 2019; 10:765. [PMID: 31249582 PMCID: PMC6582706 DOI: 10.3389/fpls.2019.00765] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
Species belonging to the Festuca-Lolium complex are often naturally infected with endophytic fungi of genus Epichloë. Recent studies on endophytes have shown the beneficial roles of host-endophyte associations as protection against insect herbivores in agriculturally important grasses. However, large-scale screenings are crucial to identify animal friendly strains suitable for agricultural use. In this study we analyzed collected populations of meadow fescue (Schedonorus pratensis) from 135 different locations across Europe, 255 accessions from the United States Department of Agriculture and 96 accessions from The Nordic Genetic Resource Centre. The analysis also included representatives of S. arundinaceus, S. giganteus, and Lolium perenne. All plants were screened for the presence of Epichloë endophytes, resulting in a nursery of about 2500 infected plants from 176 different locations. Genetic diversity was investigated on 250 isolates using a microsatellite-based PCR fingerprinting assay at 7 loci, 5 of which were uncharacterized for these species. Phylogenetic and principal components analysis showed a strong interspecific genetic differentiation among isolates, and, with E. uncinata isolates, a small but significant correlation between genetic diversity and geographical effect (r = 0.227) was detected. Concentrations of loline alkaloids were measured in 218 infected meadow fescue plants. Average amount of total loline and the proportions of the single loline alkaloids differed significantly among endophyte haplotypes (P < 0.005). This study provides insight into endophyte genetic diversity and geographic variation in Europe and a reference database of allele sizes for fast discrimination of isolates. We also discuss the possibility of multiple hybridization events as a source of genetic and alkaloid variation observed in E. uncinata.
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Affiliation(s)
- Giovanni Cagnano
- DLF Trifolium A/S, Roskilde, Denmark
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | | | | | - Flavia Pilar Forte
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
| | - Torben Asp
- Department of Molecular Biology and Genetics, Faculty of Science and Technology, Research Centre Flakkebjerg, Aarhus University, Slagelse, Denmark
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12
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Sneck ME, Rudgers JA, Young CA, Miller TEX. Does host outcrossing disrupt compatibility with heritable symbionts? OIKOS 2019. [DOI: 10.1111/oik.06182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michelle E. Sneck
- Dept of BioSciences, Program in Ecology and Evolutionary Biology, Rice Univ Houston, TX 77005 USA
| | | | | | - Tom E. X. Miller
- Dept of BioSciences, Program in Ecology and Evolutionary Biology, Rice Univ Houston, TX 77005 USA
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13
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Rice carbohydrate dynamics regulate endophytic colonization of Diaporthe liquidambaris in response to external nitrogen. FUNGAL ECOL 2019. [DOI: 10.1016/j.funeco.2019.02.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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14
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Giraldo PA, Elliott C, Badenhorst P, Kearney G, Spangenberg GC, Cogan NOI, Smith KF. Evaluation of endophyte toxin production and its interaction with transgenic perennial ryegrass (Lolium perenne L.) with altered expression of fructosyltransferases. Transgenic Res 2018; 27:397-407. [PMID: 30030680 DOI: 10.1007/s11248-018-0087-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/18/2018] [Indexed: 12/01/2022]
Abstract
Alkaloid concentration of perennial ryegrass herbage is affected by endophyte strain and host plant genotype. However, previous studies suggest that associations between host and endophyte also depends on environmental conditions, especially those affecting nutrient reserves and that water-soluble carbohydrate (WSC) concentration of perennial ryegrass plants may influence grass-endophyte associations. In this study a single transgenic event, with altered expression of fructosyltransferase genes to produce high WSC and biomass, has been crossed into a range of cultivar backgrounds with varying Epichloë endophyte strains. The effect of the association between the transgenic trait and alkaloid production was assessed and compared with transgene free control populations. In the vast-majority of comparisons there was no significant difference between alkaloid concentrations of transgenic and non-transgenic plants within the same cultivar and endophyte backgrounds. There was no significant difference between GOI+ (gene of interest positive) and GOI- (gene of interest negative) populations in Janthritrem response. Peramine concentration was not different between GOI+ and GOI- for 10 of the 12 endophytes-cultivar combinations. Cultivar Trojan infected with NEA6 and Alto with SE (standard endophyte) exhibited higher peramine and lolitrem B (only for Alto SE) concentration, in the control GOI- compared with GOI+. Similarly, cultivar Trojan infected with NEA6 and Alto with NEA3 presented higher ergovaline concentration in GOI-. Differences in alkaloid concentration may be attributable to an indirect effect in the modulation of fungal biomass. These results conclude that the presence of this transgenic insertion, does not alter the risk (toxicity) of the endophyte-grass associations. Endophyte-host interactions are complex and further research into associations with high WSC plant should be performed in a case by case basis.
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Affiliation(s)
- Paula Andrea Giraldo
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Agriculture Victoria Research, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia
| | - Carly Elliott
- Agriculture Victoria Research, Hamilton, VIC, 3300, Australia
| | - Pieter Badenhorst
- Agriculture Victoria Research, Hamilton, VIC, 3300, Australia.,School of Applied Systems Biology, La Trobe University, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia
| | | | - German C Spangenberg
- Agriculture Victoria Research, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia.,School of Applied Systems Biology, La Trobe University, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia
| | - Noel O I Cogan
- Agriculture Victoria Research, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia.,School of Applied Systems Biology, La Trobe University, AgriBio, The Centre for AgriBiosciences, Bundoora, Melbourne, VIC, 3083, Australia
| | - Kevin F Smith
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, 3010, Australia. .,Agriculture Victoria Research, Hamilton, VIC, 3300, Australia.
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15
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Fuchs B, Krischke M, Mueller MJ, Krauss J. Plant age and seasonal timing determine endophyte growth and alkaloid biosynthesis. FUNGAL ECOL 2017. [DOI: 10.1016/j.funeco.2017.06.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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16
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Fuchs B, Krischke M, Mueller MJ, Krauss J. Herbivore‐specific induction of defence metabolites in a grass–endophyte association. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12755] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Benjamin Fuchs
- Department of Animal Ecology and Tropical Biology Biocenter University of Würzburg Am Hubland D‐97074 Würzburg Germany
| | - Markus Krischke
- Department of Pharmaceutical Biology Biocenter University of Würzburg Julius von Sachs Platz 2 D‐97082 Würzburg Germany
| | - Martin J. Mueller
- Department of Pharmaceutical Biology Biocenter University of Würzburg Julius von Sachs Platz 2 D‐97082 Würzburg Germany
| | - Jochen Krauss
- Department of Animal Ecology and Tropical Biology Biocenter University of Würzburg Am Hubland D‐97074 Würzburg Germany
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Hume DE, Ryan GD, Gibert A, Helander M, Mirlohi A, Sabzalian MR. Epichloë Fungal Endophytes for Grassland Ecosystems. SUSTAINABLE AGRICULTURE REVIEWS 2016. [DOI: 10.1007/978-3-319-26777-7_6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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