Modulation of Antioxidant Defence System for Detoxification of Oxidative Stress Caused by Tannery Effluent in Eichhornia Crassipes

A study was performed to evaluate capability of aquatic macrophyte Eichhornia crassipes plants to combat oxidative stress caused by tannery effluent treatment. For this purpose, tannery effluent was collected from “Up flow Anaerobic Sludge Blanket” (UASB) Jajmau, Kanpur. Plants of Eichhornia crassipes were exposed to various concentrations of tannery effluent (0.0, 25, 50, 75 and 100%) for 2 and 7 days durations. Plants accumulated significant (p<0.01) amount of Cr (a major constituent of tannery effluent) in a concentration duration dependent manner; which was more in roots (220 mg g -1 dw) than in leaves (83 mg g -1 dw). Tannery effluent induced oxidative stress was evident by increased level of MDA content. To combat oxidative stress plants showed alleviated level of antioxidants as its defense mechanism. Among enzymatic antioxidants, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity increased over to control upto 2 nd days of treatment however on exposure of long duration i.e. 7 days these antioxidants declined in correspond to various treatments. Similarly non enzymatic antioxidants (carotenoid and ascorbic acid content) which scavenged free radicals efficiently also showing elevation at all concentrations up to 2 days exposure over unstressed plants, thereafter responded in decreasing manner due to ill effects of treatments. Therefore it can be concluded, E. crassipes can be utilized as a biomonitoring as well as phytoremedial tool using aforesaid biomarkers for pollution caused by tannery effluent.