Evaluation of localization of lead and nickel in plant cells of Amaranthus sp. and Brassica sp. absorbed from mine spoil waste

A detailed survey was undertaken in the sewage water contaminated areas of Coimbatore to select the natural hyper accumulators to rehabilitate the contaminated mine spoils. From this experiment the Pb and Ni accumulators, Amaranthus sp. and Brassica sp. were selected for further studies towards remediating the metal contaminated mine spoils. Microtomy of root, stem and leaf of Amaranthus sp. and Brassica sp. showed that the colour development in the plant species is evidence for accumulation of metals in different parts of plants and also tolerance mechanism employed by plant species under metal stress condition. The accumulation of heavy metals from soil to plant did not follow any particular pattern and varied with respect to metals, species and plant parts. However, the maximum Pb localization took place in root portion than in aerial parts. But the Ni accumulation was almost equal or higher in aerial parts (leaf and stem) compared to roots. This study revealed that the Amaranthus sp and Brassica sp stored lead and nickel in roots, leaves and stems. The roots showed more localization of metals followed by leaves and stems.