Graduate Programs in the Life Sciences

Research Focus

• identification and characterization of secondary metabolites of plants and fungi
• production/use strategies for secondary metabolites in agricultural systems

The major thrust of this research program is the discovery of new natural products which provide safer means of pest control or have high intrinsic value for the public. We search for naturally occurring compounds produced in plants, fungi, or bacteria that are capable of protecting crops from pests, and possess high target selectivity, environmental compatibility, and novel modes of action. Our search strategies have recently been expanded to include molecular screening of genomic DNA for presence of key biosynthetic enzymes for secondary metabolites of interest. These compounds may also play roles in pathogenicity, virulence, or defense, and these roles are investigated as part of our research on pest/pathogen biology. This research complements work on development of fungi as biological controls since we are using insect-pathogenic fungi from the ARS Collection of Entomopathogenic Fungi as principal source materials. It is expected that the search for natural products may also identify some compounds which may have limited use in agriculture, but may have broader utility and economic competitiveness in other arenas, such as in pharmaceuticals. Production and use strategies are a necessary followup activity to the identification and characterization work. Emphasis is placed on the most economic means of production, but our bias is fermentation technology for those biochemicals with complex structures. Fermentation technology is an emerging field for production of plant pharmaceuticals, where we have been one of the leaders in production of taxol via cell culture. Likewise, the emphasis on use strategies explores the most economic and efficacious means of using these natural products, including their use as lead chemistries.