Life Sciences Commons^™

Isolation And Culture Of Epichloё Sp. For Re-Infection Of Endophyte-Free Southeastern Wildrye (Elymus Glabriflorus), B. J. Haile, J. I. Morrison

IGC Proceedings (1997-2023)

Mutualistic relationships between endophytic fungi and grasses have shown to improve the hardiness of the host. This relationship is common in grasses, including native cool-season grasses that are important in both forage and grassland ecosystems. Elymus genus members, such as Canada wildrye (CAWR), commonly host the endophytic fungi, Epichloё, while southeastern wildrye (SEWR) may not. In this study, seed of ten Elymus accessions and seed and leaves from local SEWR were assessed for endophyte infection. Infection status was confirmed via seed squash and leaf peel techniques and assessed using microscopy. Seed of one SEWR and nine CAWR accessions were assessed …

Seed Quality Testing For Novel Endophyte Technology, N. S. Hill

IGC Proceedings (1997-2023)

Fungal endophyte (Epichloë coenophiala (Morgan-Jones & W.Gams)) in Kentucky-31 tall fescue (Lolium arundinaceum (Schreb.) Darbyshire) produces ergot alkaloids that adversely affect livestock. Novel endophyte-infected tall fescue cultivars, with agronomic enhancing properties without livestock toxicity, are commercially available but producer perception and adoption of the technology has been apprehensive. Educational programs by the Alliance for Grassland Renewal were developed to promote use of the novel endophyte technology. Standards of endophyte quality in seed for existing and new novel technologies were established and used to educate producers and ancillary professionals in Alliance-sponsored schools. Surveys of the presentation on seed quality …

Improvement In The Nitrogen Use Efficiency And Uptake Of Perennial Ryegrass (Lolium Perenne) Caused By The Epichloë Fungal Endophyte Ar37, M. A. Harmer

IGC Proceedings (1997-2023)

The forage yield and pasture persistence benefits of Epichloë fungal endophyte strain AR37 (AR37) in high rainfall perennial ryegrass (Lolium perenne) pastures in Australia and New Zealand are recognised. However, the effect of beneficial endophytes on nitrogen (N) use efficiency, yield response to applied N and N uptake had not been determined.

To investigate this, a replicated trial was managed for three years under irrigation in southern Australia. Five N application rates (0, 20, 40, 80 and 160 kg N/ha) were applied every second harvest to a tetraploid perennial ryegrass variety with and without AR37. Ryegrass biomass was …

A Global Perspective Of Epichloë Endophyte Toxicity In Sown Pastures, David E. Hume, S. C. Finch

IGC Proceedings (1997-2023)

The asexual Epichloë fungal endophytes that form mutualistic, obligate, asymptomatic associations with ryegrasses (Lolium spp.) and tall fescue (Festuca arundinacea) are critical components of pastures in the USA, Australia and New Zealand. Research has convincingly demonstrated that these endophytes enhance agronomic performance of their grass hosts, due to protection from biotic and abiotic stresses such as insect pests and drought. However, although beneficial in terms of enhancing forage quantity, the widespread occurrence of ‘common-toxic’ strains of endophyte negatively impacts the quality of forage for livestock. These bioprotective and anti-quality properties are due to endophyte-expressed secondary metabolites. It …

Assessing Endophyte Frequency Distributions And The Effect Of Epichloë Brachyelytri In The Chemotypic And Genotypic Diversity Of Brachyelytrum Erectum, Rachel Ann Sneed

Theses and Dissertations--Plant Pathology

Seed-transmissible epichloid fungal endophytes are best known for their roles as defensive mutualists in cool-season grasses. Historically, the discovery of fungal endophytes was driven by investigations of plant toxicity to livestock, followed by extensive study of their alkaloids and protection against insects and nematodes. Epichloae can produce four classes of alkaloids: ergot alkaloids, lolines (saturated aminopyrrolizidines), indole–diterpenes, and peramine. It is increasingly evident that these hereditary symbionts have much more diverse chemical profiles both in individual populations and between them. To this end, differences in chemotypic profiles of these symbionts may translate to different evolutionary and environmental advantages across plant …

Ergovaline And Ergovalinine And Tall Fescue Content Of Pastures In Central Kentucky, P. W. Long, Jimmy C. Henning, L. P. Bush

IGC Proceedings (1997-2023)

Kentucky has > 2Mha of tall fescue (Festuca arundianacea Schreb.) grown mainly for livestock consumption. Many alkaloids in tall fescue are produced in a mutualistic association between tall fescue and an endophytic fungus (Neotyphodium coenophialum) (Long et al., 2002). Ingestion of tall fescue by livestock may depress reproduction and growth (Schultz & Bush, 2002). Not all Kentucky fields of tall fescue are thought to be infected with endophyte, but forage samples from all surveyed pastures had measurable ergopeptine alkaloids. Therefore, it is reasonable to assume that some of the tall fescue plants in these fields were infected. …

Meta-Analysis Of The Effects Of Endophytes And Their Secondary Metabolites On Herbivory From Insects, Derrick Taylor

All Theses

Endophyte-infected plants have reduced the level of herbivory. The defense to herbivory can vary due to the metabolites in the plant and the method of feeding from the pest. Secondary metabolites produced by the endophytes are mainly alkaloids. The associations between endophytes and some alkaloid groups are studied in greater detail. The lack of research of certain alkaloid groups ultimately means that some alkaloids had more data that could be analyzed. As a result, the alkaloid groups were not evenly represented in the meta-analysis. The meta-analysis analyzed the relative effectiveness of the metabolites or endophytes in each of the articles …

Endophyte Effects On Antioxidants And Membrane Leakage In Tall Fescue During Drought, C. P. West, R. D. Carson, C. A. Guerber, B. De Los Reyes

IGC Proceedings (1997-2023)

Tall fescue [Festuca arundinacea (Schreb.)=Lolium arundinaceum (Schreb.) S.J. Darbyshire] infected (E+) by its fungal endophyte [(Neotyphodium coenphialum Morgan-Jones & Gams.) Glenn, Bacon & Hanlin] often shows greater persistence during summer drought than endophyte-free (E-) plants (Malinowski et al., 2005). Survival of the apical meristem and growing zone of vegetative tillers likely involves biochemical adaptations whose benefits to the host are enhanced by endophyte presence. Antioxidant enzymes may scavenge free radicals during heat and drought, and thereby reduce membrane damage. Their roles in endophyte-mediated drought tolerance in tall fescue have not been tested. Our objective was to …

Grasses As Biofactories: Scoping Out The Opportunities, Nick Roberts, K. Richardson, G. Bryan, Christine R. Voisey, W. Mcnabb, T. Conner, M. Christey, R. Johnson

IGC Proceedings (1997-2023)

1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins.
2. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis.
3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa.
4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming.

Isolation And Identification Of Potential Bioinoculants Based On Phosphate Solubilizing And Plant Growth Promoting Benefits, Rachel Raths

Electronic Theses and Dissertations

Conservative models have shown that as populations rise, food production needs to double by 2050. Population increase and the green revolution have caused fertilizer inputs to increase since the 1960’s, increasing environmental issues and production costs. These intensive practices have led to degraded arable land and there has been an increase in urbanization meaning we need to make best use of the farming land that is available and ensure it is sustainable for future food production. Due to this, there has been a higher demand for research on more environmentally and economically friendly approaches to food production. Plant growth promoting …

Intermediate Steps Of Loline Alkaloid Biosynthesis, Jerome Ralph Faulkner

University of Kentucky Doctoral Dissertations

Epichloë species and their anamorphs, Neotyphodium species, are fungal endophytes that inhabit cool-season grasses and often produce bioprotective alkaloids. These alkaloids include lolines, which are insecticidal and insect feeding deterrents. Lolines are exo-1-aminopyrrolizidines with an oxygen bridge between carbons 2 and 7, and are usually methylated and formylated or acetylated on the 1-amine. In previously published studies lolines were shown to be derived from the amino acids L-proline and L-homoserine. In addition the gene cluster involved in loline-alkaloid biosynthesis has also been characterized. In this dissertation a survey of plant-endophyte symbioses revealed a phenotype with only N-acetylnorloline. This …

Restoration Of Tall Fescue Pastures To Native Warm Season Grasslands: Does A Fungal Endophyte Symbiosis Play A Role In Restoration Success?, Sarah Lynn Hall

University of Kentucky Doctoral Dissertations

Tall fescue, a cool-season grass native to Europe, central Asia, and northern Africa, has been widely distributed throughout the U.S. for use as turf and forage. Following its widespread planting, its ability to associate with a toxic fungal endophyte, Neotyphodium coenophialum, was discovered. Research has linked this fescue-endophyte association with increased biotic and abiotic stress resistance in endophyte-infected (E+) versus endophyte-free (E-) plants, and these differences may affect the ability of land managers to eradicate tall fescue and restore native grasslands. I conducted three studies to examine whether E+ tall fescue plants respond differently to management than E- plants, …