Chlorinated Hydrocarbon Degradation in Plants: Mechanisms and Enhancement of Phytoremediation of Groundwater Contamination

9911676 Strand 本研究的目的是通过研究植物中 HHC 降解的基本机制来提高卤代烃 (HHC) 的植物修复效率，并通过基因工程提供能够更快地彻底吸收 HHC 的改良树种。 先前的研究表明，树木和其他植物能够吸收三氯乙烯、全氯乙烯和四氯化碳等 HHC 并将其氧化为氯离子和二氧化碳。中试规模试验表明，在田间生长的全尺寸杨树可以吸收大量的 HHC，同时产生很少的空气排放。 这项研究的目标是获得对植物转化机制的基本了解，并利用这些知识，通过基因工程增加植物中的 HHC 降解。 分子和生化检测表明，一种与哺乳动物细胞色素 P450 2E1 类似的植物酶参与 HHC 降解。 这项研究将寻求确定植物中 HHC 氧化的机制，分离负责该氧化的基因，进一步分析转基因植物的改进能力，并改造杨树和其他树种以优化其 HHC 氧化活性。 如果成功，这项研究可能会带来更具成本效益的方法来处理被 HHC 污染的土壤。 ***

9911676 Strand The objectives of this research are to improve the efficiency of phytoremediation of haolgenated hydrocarbons (HHCs) by studying the fundamental mechanism of HHC degradation in plants and, by genetic engineering, to provide improved strains of trees capable of more rapid ant thorough uptake of HHCs. Previous work has shown that trees and other plants are capable of taking up and oxidizing HHCs such as trichloroethylene, perchloroethylene and carbon tetrachloride to chloride ion and carbon dioxide. Pilot scale trials have shown that full-size poplar trees growing in the field can take up large amounts of HHCs while producing very little air emissions. The goal of this research is to gain a fundamental understanding of the transformation mechanisms in plants and, by using this knowledge, to increase HHC degradation in plants by genetic engineering. Molecular and biochemical assays suggest that a plant enzyme similar to the mammalian cytochrome P450 2E1 is involved in HHC degradation. This research will seek to determine the mechanism of HHC oxidation in plants, to isolate the genes responsible for that oxidation, to further analyze the improved capabilities of transgenic plants and to transform poplar and other tree species to optimize their HHC oxidative activities. If successful, this research could lead to more cost-effective means of treating soils contaminated with HHCs. ***