Transgenic Plants for Metals Phytoremediation

This Small Business Technology Transfer (STTR) Phase I project is to study the feasibility of a phytoremediation process to remove lead, a model metal, from the soil. The approach is to increase the efficiency of chelate-assisted phytoremediation of environmental contaminants by using transgenic technology to provide plants with the ability to exude significant amounts of a specific chelating agent from their roots. Isolated from the DNA of the organism pseudomonas stutzeri, this chelating agent, pyridine-2,6-bis (thiocarboxylic acid) (ptdc), has the ability to degrade carbon tetrachloride and to attain high stability constants for most heavy metals, thereby assisting preferential plant uptake of these metals into harvestable leaves and stems. In this Phase I project, the pdtc transgene will be placed under the control of plant promoters to overexpress the gene in roots. ptdc excretion will be explored in two model plants, tobacco and canola.