Distribution of Ergot Alkaloids within the Family Clavicipitaceae

Abstract

In the twenty years since the first report of an ergot alkaloid-producing endophytic fungus being the causal agent of grass-associated toxicoses in livestock (Bacon et al., 1977), the production of these alkaloids are now well documented among several grass endophytes of the family Clavicipitaceae (Porter, 1994). These endophytes have been shown to convey to the host grasses certain advantageous physiological and ecological characteristics such as increased vigor, tolerance, and resistance to drought and pests (West, 1994; Rowan and Latch, 1994). Research interests have begun to focus on the potential manipulation of the fungi to retain the beneficial qualities communicated to the plant but to down-regulate or eliminate the production of toxicosis-inducing ergot alkaloids (Schardl, 1994). However, little attention has been given to the distribution of these alkaloids within the Clavicipitaceae. While select species of grass endophytes within the genera Neotyphodium, Epichloë, and Balansia have been assayed for alkaloid production, a broad sampling of the entire family is lacking, especially among the entomopathogenic species. We have undertaken such a sampling within a phylogenetic construct and have assayed ergot alkaloid production by certain grass associates and by several species of entomopathogenic Cordyceps with the objective of more clearly defining the evolutionary history, derivation, and biological significance of ergot alkaloids within the family.