Abstract
Epichloë festucae and the asexual derivative Neotyphodium lolii, are symbiotic fungi (Clavicipitaceae, Ascomycota) that systemically colonize the intercellular spaces of leaf primordia, leaf sheaths and leaf blades of vegetative tillers and the inf orescence tissues of reproductive tillers to form symbiotic associations with temperate grasses of the subfamily Pooideae. Previous studies have established that E. festucae, N. lolii and related endophytes confer bioprotective benefits to their host plants. Host benef ts from the symbiosis include enhancement of plant tolerance to a range of biotic and abiotic stresses, including drought, disease, and animal herbivory. Indole-diterpenes are an important class of bioprotective metabolites synthesized by the Epichloë endophyte in association with temperate grasses. The major indole-diterpene synthesized by E. festucae and N. lolii in association with perennial ryegrass is lolitrem B, a potent tremorgenic mycotoxin responsible for the mammalian syndrome, known as ‘ryegrass staggers’. Peramine, the only known natural occurring pyrrolopyrazine, is a potent insect feeding deterrent uniquely synthesized by Epichloë endophyte. Production of these bioprotective metabolites and expression of biosynthetic genes are specif cally up-regulated in planta, indicated that Epichloë endophyte strictly regulate the expression of bioprotective metabolite genes for effective production of metabolites principally for the protection of host plant.
