Root exudation, the process by which plants secrete various chemicals into the soil, is the primary regulator of interactions between plants and organisms in the rhizosphere. Despite the importance of root exudation to plant biology and its implications for agriculture, the molecular and biochemical mechanisms that drive this process are still poorly understood. 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 by using a combination of molecular and biochemical techniques. The information obtained will be assembled into a public database in which specific root-exuded chemicals and their synthesis pathways will be linked to the corresponding transporters. The knowledge gained by these studies will help fill a fundamental gap in the understanding of how plants produce and secrete specific chemicals that could be used for such agriculture-enhancing projects as designing tools to over-induce the secretion of defense compounds in crops to fight pathogens and weeds.
This project will provide training for postdoctoral scientists, graduate and undergraduate students in a multidisciplinary and productive research atmosphere. It will also be used to recruit minority students for summer internships. In addition, international collaborations will be fostered through research and educational experiences at the International Potato Center (CIP) in Peru by developing a network of international colleagues who are working on plant ABC transporters. Finally, laboratory training and educational activities for high school students and teachers will be incorporated into this project so that public knowledge of plant biology and of current research techniques will be increased.
