Dr. Elizabeth (Lianne) A.H. Pilon-Smits Assistant Professor  Department of Biology pilon@lamar.colostate.edu

The research program centers on understanding the mechanisms by which plants metabolize and accumulate pollutants, with the goal to improve the capacity of plants to remove these compounds from the environment (phytoremediation). All aspects of phytoremediation, from the molecular level to the whole plant level to the field, are of interest. One important class of compounds which form a serious environmental problem are trace elements. The goal is to identify which steps are rate-limiting for the phytoremediation of different trace elements and to use genetic engineering to improve phytoremediation efficiency. For these studies, Indian mustard (Brassica juncea ) is used as a model system. This plant is a good remediator of most trace elements, and can be genetically engineered. Eight enzymes involved in selenium or heavy metal accumulation have already been overexpressed in Indian mustard. Overexpression of two enzymes responsible for the uptake and reduction of selenate both resulted in increased selenium accumulation and tolerance. Other transgenic plants, overproducing the heavy metal binding peptides called phytochelatins, showed increased cadmium accumulation and tolerance. Future research will focus on the creation and physiological analysis of transgenic plants, trace element physiology, and in situ phytoremediation of polluted soil or water.