Chapter 11 - Transgenic Brassicaceae: A Promising Approach for Phytoremediation of Heavy Metals

Abstract

The contamination of the environment with toxic metals and metalloids due to unprecedented anthropogenic activities has become a global problem affecting crop yield and fertility of soil; poses a serious threat to plants and animals including humans. Phytoremediation, the plant-based cleanup of contaminated and toxic soils, sediments, and/or groundwater, has great potential and has arisen as a cost-effective, environmentally friendly, and solar-driven technology. Some plants, called hyperaccumulators (many in the Brassicaceae family), can accumulate large amounts of heavy metals (HMs), and thus are potential candidates for phytoremediation. This potential can further be greatly improved with the advancement of transgenic approaches like overexpression/alteration of native plant specific gene(s) and/or insertion of chimeric gene(s) producing a transgenic variety whose protein products are mainly involved in efficient metal uptake and transport via specific transporters, membrane channels, and enzymes. The overexpression/alteration of gene(s) related to phytochelatins and glutathione helps in sequestration of toxic HMs in the vacuoles and provides an opportunity to alter metabolism in vivo. Overexpression/alteration of gen (s) related to defense system/pathways of plants such as antioxidants, proline, polyamines, etc. could also help plants against metal toxicity by quenching destructive reactive oxygen species. In a nutshell, elaborate and deep transgenic strategies along with physiological approaches in Brassicaceae family members pave the way to develop agronomically useful traits like more tolerance, resistance, and adaptability in transgenic varieties than their wild counterparts. It will open up new windows for efficient and successful phytoremediation as well.