Toxicity of Epichloë endophytes in agricultural grass species on pastures

• Applicant: Professor Dr. Jochen Krauss
• Subject Area: Ecology of Land Use ; Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems ; Plant Breeding and Plant Pathology
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 467000317

The main objective of this project is to understand the distribution and toxicity of systemic endophytic fungi of the genus Epichloë in cool season grass species in German pastures and in commercially available seed mixtures. In a first work package, Epichloë species as well as genotypic and chemical diversity of pathway alkaloids and endproducts will be quantified from 150 seeded pastures (50 cattle, 50 sheep and 50 horse pastures) across Germany. In addition, 50 semi-natural grasslands with grazing sheep and 50 seeded horse pastures with severe cases of the disease laminitis in horses will be tested. Seed mixtures used for the 200 pastures will be also analyzed, to find the possible sources of Epichloë infected host grass and toxic compounds. In a second work package, we will purchase commercially available seed mixtures for pastures and lawns from the European and international market to search again for the occurrence of Epichloë endophytes and their alkaloids. When seed mixtures should contain Epichloë infected seeds, we will sow out the mixture in the University garden and detect alkaloids in one-year-old plants, to estimate their toxicity. We finally will ask the main seed producers in Europe and the Federal Office of Plant Varieties in Germany to get grass cultivars of infected seed mixtures, to detect the source of Epichloë infections. With this project, I want to add scientific data to an upcoming debate in society about symbiotically modified organisms. Thereby it is unknown if and to which extend seed breeders of grass deliberately use these new technologies and if seeded grass on pastures could harm livestock. With this study, I aim to address the following key research questions:(1) Are the occurrence of Epichloë endophytes and the alkaloid concentrations in grass different in seeded pastures of horses, cattle and sheep? (2) Have seeded pastures different Epichloë endophytes compared to semi-natural grasslands with livestock? (3) Is laminitis in horses related to Epichloë endophyte occurrence and alkaloid concentrations in the grazed grass? (4) Which grass seed mixtures in Europe are infected with Epichloë endophytes, and are the mixtures toxic for livestock and can they protect the host grass from insect herbivory? (5) Which European grass cultivars are infected with Epichloë endophytes?

• DFG Programme: Research Grants