PHYTOREMEDIATION POTENTIAL AND BIOCHEMICAL RESPONSE OF OIL CROPS TO SOIL HEAVY METALS - A CASE STUDY WITH ARACHIS HYPOGAEA L. (FABACEAE)

Abstract

The objective of the present study was to investigate the phytoremediation ability of oil seed crop, Arachis hypogaea L. A pot experiment was conducted with different concentrations of lead (Pb), cadmium (Cd) and chromium (Cr) as lead nitrate (Pb (NO3)2 , Cadmium chloride (CdCl2 ) and potassium dichromate (K2Cr2O7 ) based upon the threshold level for 30 and 60 days. Generally, the value of heavy metal was found to be in the decreasing order Cd > Pb > Cr. The obtained values were used to evaluate the Bio Concentration Factor (BCF) and Translocation Factor (TF), indicating the ability of phytoextraction and transport of heavy metals in the plant. Results showed that the BCF value of Cd and Cr was greater than 1(BCF>1) in root and shoot after 30 and 60 days of interval while Pb was higher than 1 in the root only after 60 days of interval. This indicates that the plant act as a Pb, Cd and Cr hyperaccumulator. The TF value greater than 1 (TF>1) for Cd, only after 30 days of interval indicates the metal accumulation and transport to different plant parts fromroot. In order to reduce the oxidative stress with the production of Reactive Oxygen Species (ROS), the enzymatic and non enzymatic antioxidant response of A. hypogaea were also evaluated. Pb induced oxidative stress causes a significant increase in the activity of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC.1.11.1.6), peroxidase (POX; EC.1.11.1.7), ascorbate peroxidase (APX; EC 1.11.1.11), polyphenol oxidase (PPO; EC.1.14.18.1), ascorbic acid andproline than Cd and Cr treated plant.