Epichloe fungal endophytes and the formation of synthetic symbioses in Hordeeae (=Triticeae) grasses

This review examines two classes of organism that live in symbiosis; grasses, and fungi. Specifically it deals with grasses of the tribe Hordeeae (formerly Triticeae) of the subfamily Pooideae and the Epichloe fungi of family Clavicipitaceae. Epichloe endophytes, particularly asexual forms, have important roles in pastoral agricultural systems in the Americas, Australia, and New Zealand. Selected strains add value to some grass-based forage systems by providing both biotic and abiotic stress resistance. The importance of cereal grasses such as wheat, barley, rye, and oats to human and animal nutrition and indeed to the foundation and maintenance of human civilization is well documented. Both organism classes, Epichloe endophytes and cereal grasses, are of great importance in their own contexts. Here, we seek to review these two classes of organism and examine the possibility of bringing them together in symbiosis with the ultimate goal of improving cereal production systems.