Phytoremediation uses plants to degrade, remove or stabilize toxic compounds from contaminated soil and water. The serious problem of soil contaminated with heavy metals or organic chemicals affects human health, ecosystem functions and agriculture. Experts estimate the cost of soil cleanup in the United States in the billions of dollars. Researchers believe that phytoremediation could provide an extremely cost-effective and much less disruptive cleanup process when compared to traditional cleanup techniques, such as transporting massive amounts of contaminated soil to hazardous waste landfills.
NSF is funding three multidisciplinary research projects that will investigate the genetic components of phytoremediation of heavy metals in soils. One project will determine the suite of genes responsible for heavy-metal hyperaccumulation in Thlaspi caerulescens. A second will perform a search of the genomes of brassicaceous plants for genes involved in metal hyper accumulation. A third will study the mechanisms of arsenic uptake, translocation, distribution and detoxification by the Brake fern, a common fern in the southeastern U.S. and California. The research awards come from NSF's Integrative Plant Biology and Environmental Engineering/Environmental Technology Programs.
EPA research projects are diverse and designed to explain the mechanisms for phytoremediation of organic chemicals including polyaromatic hydrocarbons, polychlorinated bi-phenyls, and chlorinated pesticides. Knowledge will be unearthed to better understand three scientific problems: the microbial ecology of chemical-degrading bacteria that live in the root systems of monoterpene-producing plants; the role of chemicals produced by roots that aid in making the organic chemicals available for uptake and metabolism by plants; and the role of plant-transported oxygen for degradation of organic contaminants in waterlogged, low-oxygen salt marsh sediments or soils. The grants for these studies were awarded through EPA's Science to Achieve Results (STAR) program.
The multi-agency funding for this initiative - made through the Joint Program on Phytoremediation - also includes the Office of Naval Research and the DOD/DOE/EPA Strategic Environmental Research and Development Program.
ATTACHMENT: Summary of Awards
SUMMARY OF NSF/EPA AWARDS FOR PHYTOREMEDIATION
NATIONAL SCIENCE FOUNDATION
Boyce Thompson Institute, Cornell University - Principal Investigator: Leon V. Kochian - "The Molecular Basis for Heavy Metal Accumulation and Tolerance in the Hyperaccumulating Plant Species, Thlaspi caerulescens." The research will lead to identifying hyperaccumulation genes, which could be used to develop transgenic plants that are both metal hyperaccumulators and produce high shoot biomass, and thus well suited for the phytoremediation of metal contaminated soils. A focus will be the metal transporter genes involved in metal accumulation and tolerance, as well as genes involved in the production of compounds that bind and detoxify zinc and cadmium in plant cells.
Purdue University - Principal Investigator: David E. Salt "GenomeWide Hunt For Metal Hyperaccumulation Genes." Although known metal hyperaccumu- lators are not well suited for phytoremediation because of their small size and slow growth, they are a unique source of genes for this process. Over 25 percent of the known hyperaccumulator species are from the Brassicaceae family. Researchers will collect metal hyperaccumulating Brassicaceae from around the world and identify the important hyperaccumulation genes using three complementary molecular approaches. This approach will identify genes that can be used for the future development of plants for phytoremediation.
Northwestern University - Principal Investigator: Jean-Francois Gaillard and The University of Florida, Principal Investigators: Lena Q. Ma lqma, Yong Cai, David M. Sylvia and Kelsey R. Downum "Understanding and Enhancement of Arsenic Hyperaccumulation by a Fern Plant." This research will elucidate the mechanisms of arsenic uptake, translocation, distribution and detoxification by Brake fern. Arsenic hyperaccumulation characteristics of Brake fern growing in soils of different arsenic concentrations will be investigated. The research will examine the impacts of phosphorus and calcium on arsenic accumulation, as well as the beneficial effects of mycorrhizal fungi for enhancing arsenic accumulation.
For more information on the NSF grants, contact:
Andrea Dietrich, (703-292-8070) or see: http://www.
ENVIRONMENTAL PROTECTION AGENCY
University of California at Riverside - Principal Investigators: David E. Crowley, James Borneman - "Evaluation of Monoterpene Producing Plants for Phytoremediation of PCB and PAH Contaminated Soils." The objective of this research is to evaluate plant species that produce a specific group of chemicals (monoterpenes) for use in phytoremediation of PCBs and PAHs. The research will also investigate the ecology of chemical-degrading bacteria that live in the root systems of monoterpene-producing plants. Results of this research will provide information on the mechanisms by which plants influence the growth of PCB- and PAH degrading bacteria in plant root systems.
Connecticut Agricultural Experiment Station and The University of Connecticut - Principal Investigator: Jason C. White "Mechanistic Role of Plant Root Exudates in the Phytoremediation of Persistent Organic Pollutants." This research will investigate the role of plant roots in the phytoremediation of persistent organic pollutants in soil. Preliminary data indicate that the uptake of two organic pollutants (p,p'-DDE, chlordane) from soil into roots is increased in selected plant species. This research will determine whether chemicals produced by roots have the potential to increase the bioavailability of certain contaminants for plant uptake and metabolism.
Washington State University - Principal Investigator: Raymond Lee - "Physiological Mechanisms of Estuarine Sediment Oxidation by Spartina Cordgrasses." Cordgrasses of the genus Spartina will be investigated for their potential use as a phytoremediation tool in marine and estuarine sediments. Spartina grasses are adapted to saline, waterlogged sediments and exhibit vigorous growth, forming dense stands in a variety of intertidal environments. This research will determine whether the ability of these plants to transport oxygen from the atmosphere to their below-ground root systems has the potential to enhance microbial degradation of organic pollutants, which can be limited by oxygen availability in anoxic, waterlogged soils.
For more information on the EPA grants, contact:
Estella Waldman, (202-564-6836) or see: http://www.
Media contact: Andrea M. Dietrich
Joann P. Roskoski