Phytoremediation of Heavy Metal contaminated Soils Using Transgenic Plants

Current physical and chemical methodologies, conventionally used to clean up metal contaminated soils, are generally too expensive to apply in large hazardous waste sites including agricultural lands adjacent to closed or abandoned metal mines. Phytoremediation using plants to extract, sequester and detoxify environmental pollutants is one of the cost-effective and aesthetically-pleasing alternatives, compared with environmentally destructive remedial methods currently being practiced. But, phytoremediation has some limitations such as time consuming and low performance: in general, it is seasonally dependent and slower in removing metals than other methods, and metal accumulating plants are slow growers. Improvement of plants for metal tolerance, accumulation, and translocation using genetic engineering techniques recently opened up new possibilities for phytoremediation. In this paper, we have discussed about recent developments in conventional and genetically engineered phytoremediation. For the conventional phytoremediation, focuses are on the natural hyperaccumulator and the chemically assisted phytoremediation. Some pros and cons on the phytoremediation using transgenic plants, coupled with focusing on the mechanistic view points, are also discussed. It might be concluded that the transgenic plants will be effective tools in the practical application of phytoremediation especially for the highly contaminated soils but mechanisms involved should be deeply understood in advance.