Alleviation of chromium induced toxicity in Cicer arietinum L. seedling by calcium

Abstract

The present study intends to assess the role of calcium (Ca2+) in elevating endurance capacity and ameliorating chromium toxicity in chickpea seedlings, as calcium is a potential stress reliever by interacting with signaling pathways. Being a valued protein rich crop of India and susceptible to Cr contamination from irrigated water, toxicity amelioration study of chickpea is justified. Calcium was applied alone (10 mM, 20 mM) and also in combination with Cr (25 μM and 50 μM) to antagonize the damaging effect of Cr and to restore the plant growth in chickpea seedling. The exogenous application of Ca alleviates the detrimental effects of Cr by the upregulation of antioxidative enzymes, such as catalase (CAT), peroxidase (POD), glutathione reductase (GR) as well as non enzymatic antioxidants (proline, phenol, non-protein thiol). Formation of endogenous H O was moderately reduced with the supplementation of Ca with increasing chromium 2 2 concentrations in comparison to control plants. The formation of Malondialdehyde (MDA) which is the indicator of membrane damage due to lipid peroxidation showed significant reduction with Ca co-treatment. Though CAT and GR revealed elevated activity for both concentration of Cr with Ca supplementation, super oxide dismutase (SOD) activity was not upregulated very significantly. Ca dependent toxicity mitigation was more pronounced in 25 μM Cr treatment rather than 50 μM and 20 mM Ca supplementation was found to be more effective. This investigation will help the potential fields of remediation and mitigation of Cr toxicity in near future.