Genetic engineering stress tolerant plants for phytoremeditation

Abstract

Phytoremediation uses plants and associated microbes to remove, sequester, and detoxify contaminants, particularly trace elements. The great potential of this low-cost, low-management approach has spurred researchers to increase the efficiency of this natural process through the use of genetic engineering. Plants used for phytoremediation face a primary stress emanating from the high local concentrations of contaminants as well as possible secondary stresses such as extreme temperature, salinity, desiccation, flooding, and/or high light. Since the total amount of a contaminant removed is a product of the total biomass of the harvestable tissue and the concentration of the contaminant in those tissues, it is critical that phytoremediating plants tolerate contaminant stress through detoxification mechanisms rather than avoidance or exclusion mechanisms. At the same time, they should survive the sub-optimal growth conditions often associated with contaminated sites. For this reason, the introduced genes often play a role in increasing the stress tolerance of the engineered plants. Successful genetic engineering approaches range from the transfer of genes with specific detoxification function to overexpression of genes involved in ameliorating oxidative stress in general. Advances in related fields, including rapid genome sequencing, microarrays, and more sophisticated gene expression systems, should eventually lead to an increase in the number of engineered plants suitable for field-use. © 2006 Springer. All Rights Reserved.