Project 5
Phytoremediation of Organic Pollutants Using Transgenic Plants

Trichloroethylene and other volatile organic compounds (VOCs) are among the most commonly found pollutants in groundwater. Deep-rooted trees can take up and degrade VOCs (called phytoremediation), but not fast enough for most practical applications. At the UW we have developed genetically modified poplars that take up and degrade VOCs much faster than unmodified trees. Using these modified plants VOCs like trichloroethylene are completely degraded to CO2 and table salt. We are presently setting up full scale tests of genetically modified poplar to compare their uptake of trichloroethylene with that of unmodified trees using mass balance techniques, with which we can account for all inputs of trichloroethylene and outputs of degraded products. We will also test the ability of transgenic plants to remove VOCs from air, which could help improve the quality of indoor air in our homes. Simultaneously we are continuing to analyze plant metabolism of VOCs using plant genome sequences. These experiments are expected to yield important clues about which genes are involved in the degradation of the pollutants and how that degradation can be increased. New work will also focus on the introduction into plants of genes for the degradation of toxic pesticides such as chlorpyrifos. With our new knowledge of the genes involved in degradation of pollutants, we will be able to design superior plants for phytoremediation through genetic engineering.

Recent publications:

READ Kang JW, Khan Z, and Doty SL. (2012) Biodegradation of trichloroethylene by an endophyte of hybrid poplar. Appl Environ Microbiol. May;78(9):3504-7. Epub 2012 Feb 24.

READ Lee KY, Strand SE, and Doty SL. (2012) Phytoremediation of chlorpyrifos by Populus and Salix. International Journal of Phytoremediation 14(1):48-61.

Dhanker, O.P., Pilon-Smits, E., Meagher, R., and Doty, SL (2011) "Chapter 20: Biotechnological Approaches to Phytoremediation" In Plant Biotechnology and Agriculture: Prospects for the 21st Century. A. Altman and M. Hasegawa, eds. Elsevier.

READKang, JW, Wilkerson, H-W, Farin, FM, Bammler, TK, Beyer, RP, Strand, SE, and Doty, SL. (2010) Mammalian cytochrome CYP2E1 triggered differential gene regulation in response to trichlorothylene (TCE) in transgenic poplar. Functional & Integrative Genomics Aug;10(3):417-24.

Van Aken, B. and Doty, SL. (2010) Transgenic plants and associated bacteria for phytoremediation of chlorinated compounds. Biotechnology and Genetic Engineering Reviews 26:43-64.

Recent presentations:

READ Doty, SL and Lee KY. Eco-Friendly Plants at Work. Seattle Expanding Your Horizons Conference, Bellevue, WA. 2009, 2010, 2011 and 2012.

International Poplar Symposium.  Sept 20-25, 2010.  Orvieto, Italy.  Keynote lecture.  “Phytoremediation of TCE, Explosives, and Pesticides using Poplar.”

Annual Meeting of American Society of Plant Biologists. July 18-22, 2009. Honolulu. Battelle’s 7th International Conference on Remediation of Chlorinated and Recalcitrant Compounds. May 24-27, 2010. Monterey, California. Platform speaker. “Phytoremediation of TCE and Explosives by Transgenic Aspen.” Sharon L. Doty, Jun Won Kang, Hui-Wen Wilkerson, Federico M. Farin, Theo Bammler, Richard P. Beyer, Neil Bruce, and Stuart E. Strand.

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