University of California-San Diego

Project Summary (2000-2005)

Previous studies suggest that uptake of heavy metals into plants via the root system could provide a potent and cost effective approach for toxic metal removal and remediation of soils and waters. In plants and fungi, phytochelatins are major heavy metal chelating and detoxifying thiolate peptides that form complexes with and detoxify heavy metals, including Cd, Zn, Pb, Hg and As. The enzyme phytochelatin synthase (PCS) produces phytochelatins, thus functioning as a major catalytic metal detoxification mechanism in plants. Project researchers are testing the hypotheses that stress-signaling pathways contribute to PCS induction and detoxification, and that transgenic expression of PCS genes can, together with other metal-interacting mechanisms, enhance heavy metal hyperaccumulation and removal by plants. Results from these studies could play a central role in the development of future phytoremediation strategies for heavy metal uptake and biological removal of heavy metals from contaminated soils and waters.