A Tale of Two Grass Species: Temperature Affects the Symbiosis of a Mutualistic Endophyte in Both Tall Fescue and Perennial Ryegrass.

Many cool-season grasses form permanent, mutualistic symbioses with asexual 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.