Heavy metal induced gene expression in Brassicaceae

Plants require at least 14 mineral elements for their nutrition. These include the macronutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S) and the micronutrients boron (B), chlorine (Cl), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), nickel (Ni) and molybdenum (Mo). These are generally obtained from the soil. Crop production is often limited by low bioavailability of essential mineral elements and/or the presence of excessive concentrations of potentially toxic heavy metals, such as Fe, Mn, Cu, Cr, Cd, Pb, Zn and Al in the soil solution. In the past few years, responses of plants to heavy metals have received increasing attention. On one hand due to industrial activities, toxic heavy metals such as Cd, Zn, Cu, Cr, Pb have been released into the biosphere and represent a widespread environmental pollution. High concentrations of heavy metals in the soil can inhibit plant growth and reduce crop yields, which can affect sustainable development severely. In order to study the molecular response of plants to heavy metals, the gene expression data of model crop plants especially in Brassicaceae family were analyzed by searching several databases available online. In the first part of this work the publicly available online resources for these plants from websites such as http://www.ncbi.nih.gov, http://www.tigr.org, http://www.brassica.info, and related sites were searched to collect nucleotide sequences that encode heavy metal ATPases and transporter protein homologues. The second part of this work focuses on the expression of these genes in plants grown at different concentrations of Cu, Zn, and Cd. Real time PCR (RT-PCR) experiments will be carried out to analyze the expression of these genes in roots and shoots of B. nigra and B. juncea treated with different concentrations of metals. Keywords: Arabidopsis thaliana, Brassicaceae, phylogenetic tree, Metal ATPases, phytoremediatio