Plant Genetic Resources Can Improve Our Understanding and Utilization of Endophytes.

Plant genetic resources can improve our understanding and utilization of endophytes.

A. A. Hopkins and C.A. Young

Endophytic fungi, such as Epichloë and Neotyphodium species, form mutualistic symbioses with cool season grasses and act as biological agents for growth and persistence.  Epichloë endophytes are known to produce a range of bio-protective alkaloids with known anti-fungal, anti-insect and anti-herbivore properties. We are exploring plant germplasm to identify endophytes that can enhance plant performance without having detrimental effects on livestock health.  In addition, endophyte germplasm is being characterized to improve our understanding of alkaloid biosynthetic pathways and host-endophyte compatibility.  Cool season grass germplasm has been obtained from the USDA National Plant Germplasm System and collections made in the USA, Mexico, and Greece.  Plants are screened for the presence of epichloë endophytes, which are then cultured and maintained as lab stocks.  Molecular screens are conducted by PCR to characterize the presence or absence of known alkaloid biosynthesis genes, such as those for ergot alkaloids and lolitrems.  Tissue from endophyte infected plants is analyzed to confirm alkaloid profiles.  Correlation between natural genetic variants and alkaloid profiles can be used to identify candidate genes involved in the production of specific compounds and pathway intermediates. Promising endophyte isolates can be inoculated into plants to determine host range and ultimately the bio-protective and mammalian toxicity potential of an endophyte.