Fescue toxicosis affects wild and domestic animals consuming ergot alkaloids contained in tall fescue forage infected with the endophytic fungus, Neotyphodium coenophialum. When animals are consuming infected fescue (E+) forage during periods of elevated ambient temperatures (summer), a range of phenotypic disorders collectively called summer slump is observed. It is characterized by hypertherm...

Many grasses have mutualistic symbioses with fungi of the family Clavicipitaceae. Tall fescue can harbor the obligate endophyte, Neotyphodium coenophialum that is asexually propagated and transmitted via host seeds. Total RNA was isolated from pseudostems of known endophyte-infected (E+) and endophyte-free (E-) plants and tested in triplicate on the Affymetrix Wheat Genome Array GeneChip and Ba...

Tall fescue (Schedonorus phoenix (Scop.) Holub) is a cool-season bunchgrass that grows throughout the eastern half of the United States and in the Pacific northwestern region of the country. It is estimated that over 90% of tall fescue pastures are infected with the fungal endophyte Neotyphodium coenophialum (Bacon and Siegel, 1988; Glenn et al., 1996). Tall fescue is native to Europe and was f...

Loline alkaloids are produced by mutualistic fungi symbiotic with grasses, and they protect the host plants from insects. Here we identify in the fungal symbiont, Neotyphodium uncinatum, two homologous gene clusters (LOL-1 and LOL-2) associated with loline-alkaloid production. Nine genes were identified in a 25-kb region of LOL-1 and designated (in order) lolF-1, lolC-1, lolD-1, lolO-1, lolA-1,...

Alkaloids produced by the fungal endophyte (Neotyphodium coenophialum) that infects tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] are a paradox to cattle production. Although certain alkaloids impart tall fescue with tolerances to environmental stresses, such as moisture, heat, and herbivory, ergot alkaloids produced by the endophyte can induce fescue toxicosis, a malady that adversely a...

• Climate change (altered CO(2) , warming, and precipitation) may affect plant-microbial interactions, such as the Lolium arundinaceum-Neotyphodium coenophialum symbiosis, to alter future ecosystem structure and function. • To assess this possibility, tall fescue tillers were collected from an existing climate manipulation experiment in a constructed old-field community in Tennessee (USA). Endo...

Tall fescue (Festuca arundinacea Schreb.) is the most commonly used cultivated grass in the United States to feed beef cattle. Tall fescue is a cool-season perennial grass that many cattle producers ‘can’t live with, but can’t live without’ because of its hardiness and good forage yields, but adverse effects on cattle well-being and yields. The history of this forage and its effects on animal p...

Grass-associated fungi (grass symbionts) in the family Clavicipitaceae (Ascomycota, Hypocreales) are species whose host range is restricted to the plant family Poaceae and rarely Cyperaceae. The best-characterized species include Claviceps purpurea (ergot of rye) and Neotyphodium coenophialum (endophyte of tall fescue). They have been the focus of considerable research due to their importance i...

Most organisms engage in beneficial interactions with other species; however, little is known regarding how individuals balance the competing demands of multiple mutualisms. Here we examine three-way interactions among a widespread grass, Schedonorus phoenix, a protective fungal endophyte aboveground, Neotyphodium coenophialum, and nutritional symbionts (arbuscular mycorrhizal fungi) belowgroun...