Phytoremediation of Organic Pollutants Using Transgenic Plants
Stuart Strand, Director
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.