Phytoremediation of heavy metals contaminated soils through transgenic plants

Abstract

The contamination of the environment with toxic metals has become a worldwide problem. Metal toxicity affects crop yields, soil biomass, and fertility. Soils polluted with heavy metals pose a serious health hazard to humans as well as plants and animals, and often requires soil remediation practices. Phytoremediation, the use of plants and their associated microbes to remedy contaminated soils, sediments, and groundwater, is emerging as a cost-effective and environment friendly technology. Phytoremediation uses different plant processes and mechanisms normally involved in the accumulation, complexation, volatilization, and degradation of organic and inorganic pollutants. Certain plants, called hyperaccumulators, are good candidates in phytoremediation, particularly for the removal of heavy metals. Phytoremediation efficiency of plants can be substantially improved using genetic engineering technologies. Recent research results, including overexpression of genes whose protein products are involved in metal uptake, transport, and sequestration, or act as enzymes involved in the degradation of hazardous organics, have opened up new possibilities in phytoremediation of heavy metal-contaminated soils.