Phytoremediation: Uptake and Role of Metal Transporters in Some Members of Brassicaceae

Abstract

Plants absorb water and minerals for their growth and survival from the matrix they grow upon. For every resource absorbed, there is a specific pathway for its translocation. While water finds its way through semipermeable plasma membrane and also through aquaporins to some extent, minerals get their entry along with it due to their soluble nature. With these, heavy metals also enter the plants through specific metal transporters. These metal transporters have remained conserved to some extent throughout evolution. Phytoremediation reports claim that most of the efficient phytoremediators belong to the family Brassicaceae. Heavy metal transporters namely Zinc-regulated transporter (ZRT), Iron regulated transporter (IRT), ZRT-, IRT-like proteins (ZIP), Natural resistance-associated macrophage proteins (NRAMP), Cation diffusion facilitator (CDF)/Metal tolerance protein (MTP), Heavy metal ATPase (HMA), Endomembrane-type CA-ATPase (ECA), Detoxification (DTX), Magnesium/Proton Exchanger (MHX), and Copper transporter (COPT) have been identified in Arabidopsis thaliana. Many researches showed that some of these genes are upregulated in Arabidopsis halleri, a hyperaccumulator. The difference in regulation of these genes is responsible for the potential in A. halleri. The aim of present study is to identify heavy metal transporters in Brassica rapa and Brassica oleracea, so that they can be engineered upon by molecular techniques in future, making them highly efficient for the treatment of contaminated sites.