ABC Transporters: The Genetic Key to Exudation?

In collaboration with Dr. Frank Stermitz of the Chemistry department, my lab has just obtained a $1.1M grant from the National Science Foundation to study the role of a group of proteins called ABC transporters in the root exudation. Virtually nothing is known about the molecular mechanisms by which roots secrete phytochemicals into the rhizosphere. Specifically, this project will provide a detailed characterization of ATP-binding cassette (ABC) transporter genes involved in root exudation, using Arabidopsis thaliana as a model plant. The ABC transporter genes, found in organisms in all kingdoms, encode the proteins responsible for the transport of a wide variety of critical substances across cellular membranes. At least 25 ABC transporter genes involved in root exudation will be characterized. The tissue-specific expression of these genes will be investigated under inducing conditions known to affect metabolic activity and root secretion. Root exudation offers a unique system for identifying specific substrates for a large number of ABC transporters, and we expect that some transporters will be specific to certain chemicals while other transporters will be more generalist. This project will greatly enhance our understanding of the biochemical role of ABC transporters in plants, and will help provide the tools to over-induce the secretion of compounds in crops to fight against pathogens and weeds.

Dr. Victor Loyola-Vargas