Interactive Effects of EDTA and Oxalic Acid on Chromium Uptake, Translocation and Photosynthetic Attributes in Indian Mustard ( Brassica juncea L. var. Varuna)

The accumulation and toxicity of chromium (Cr) in Indian mustard (Brassica juncea L.) under ethylene diamine tetraacetic acid (EDTA) and oxalic acid (OA) as chelating agents was studied. Plants were exposed to Cr(VI) and chelating agents in four experimental set-ups as Cr(VI), Cr(VI) + EDTA (1 : 1), Cr(VI) + OA (1 : 1) and Cr(VI) + EDTA + OA (1 : 1 : 1), where each set-up comprised of 0, 6.25, 12.5 and 25.0 mg of Cr(VI) and/or chelating agents in 250 g of soil. Results conferred that EDTA augmented bio-concentration factor in all the three doses of Cr(VI), OA considerably increased translocation factor in all the treatments, including control, and the combined application of the two chelates escalated both the aforesaid factors. Moreover, these chelating agents help in ameliorating Cr(VI) toxicity asserted by low degree of lipid peroxidation, insubstantial damage in ischolar_main and shoot length, fresh and dry biomass, chlorophyll and leaf gas exchange parameters. Besides, plants showed a robust detoxification mechanism primarily by significant (P < 0.05) production of reduced glutathione and phytochelatins among other enzymatic and nonenzymatic antioxidants under these chelating agents. The present findings suggest that Indian mustard could be used as a potential phytoremediator of Cr(VI) under the combined application of EDTA and OA.