Indian Mustard Brassica juncea efficiency for the accumulation, tolerance and translocation of zinc from metal contaminated soil

Phytoremediation using hyper accumulators is an emerging and cost-effective option for heavy metal pollution cleanup in soils. There is a dearth of knowledge regarding mechanism of sequestration of heavy metals and their final destination allocated at cellular levels by hyper accumulators. The present study explores the accumulation, tolerance, toxicity, translocation and cellular level accumulation of essential heavy metal Zn in Indian Mustard (Brassica juncea). Accumulation of Zn in roots leaves and stem of Brassica juncea was also quantified by Atomic Absorption Spectroscopy (AAS). Plants were grown in sand and soil and were given Zn concentrations (20, 40, 80, and 160 mg/L) for four weeks. The results of this study showed that tolerance index increased with increased concentration of metal. Translocation factor for each concentration of Zn was greater than 1 which showed aerial parts of plants accumulated more amount of metal than their roots. Highest EC50 value was observed in stem and lowest EC50 value was observed in root of Brassica juncea. Zn deposits were found in epidermis, bundle sheet of veins and mesophyll cells of Brassica juncea leaves. Brassica juncea tolerated and grew well even at higher concentrations of Zn. Zinc accumulation in leaf tissues increased as given concentration of Zn increased.