Trace Metals Accumulation and Antioxidants Profiling in Two Maize Genotypes Against Sewage and Textile Wastewater Treatment

Abstract

Shortage of freshwater resources compels farmers to use sewage and textile effluents for irrigation, leading to accumulation of trace metals (Cr, Cu, Pb, Cd, Ni) to toxic levels and affecting plant growth and harming animals and humans. An experiment is conducted using raw (1:0) textile (TEX) and sewage (SWG) effluents and their dilution (1:1 and 1:3) by tap water (TAP) to assess the physiological changes against the trace metals accumulation in maize genotypes (999 and 984). Dilution of TEX and SWG effluents causes an increase in the uptake of trace metals in both genotypes, thereby decreasing metals accumulation in soil. Application of raw TEX and SWG effluents enhances lipid peroxidation (malondialdehyde, MDA) concentration and decreases by increasing dilution. The activities of antioxidants enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX; total antioxidants activity) are significantly higher in raw (1:0) treatment of TEX and SWG effluents compared to TAP treatment and decrease by increasing dilution. The activity of glutathione reductase (GR) increases by increasing dilution of effluents. The maize genotype “984” shows significantly higher values of measured antioxidant enzymes and lower MDA compared to “999.” The differential accumulation of trace metals in maize genotypes shows varied activities of the antioxidant enzymes responsible for their differences in growth and adaptability against trace metals toxicity. The plants' genotype tolerance against trace metals toxicity and effluents dilution is an effective measure to avoid entry of these metals into food chain.