ALTERATION OF AMYLASE AND PHOSPHATASE IN Macrotyloma uniflorum UNDER INFLUENCE OF CADMIUM, MERCURY AND ZINC STRESSES
Physical weathering of parent rocks, mining, and other anthropogenic activities lead to impermissible levels of heavy metals in plant tissues. Effect of Cd2+, Hg2+, and Zn2+ on metabolic enzymes, Amylase (EC; 184.108.40.206), and AP (EC; 220.127.116.11), were studied to assess horse gram response to these heavy metal stress. Enzyme activity and TC were evaluated. Amylase decreased in response to increasing Cd2+ concentration, with great impact at 48-72h. It rose under 5 ppm Hg2+, while dropped under 10 ppm beyond 24h reaching ~25% of control, and recovered with time to reach 80-90% under 20 ppm. Under Zn2+ stress, amylase rose in concentration- and time-dependent manner. AP declined under metal stress in concentration, time-dependent manner, except at 100 ppm Zn2+. TC fluctuated in metal-specific manner with positive influence by Zn2+ (300-600 ppm) and Cd2+ (100-200 ppm) at 24 h. TC diminished under Cd2+ stress beyond 24 h, and over entire duration under Hg2+ stress. It can deduce that Hg2+ and Cd2+ exhibited toxic effects on horse gram while Zn2+ had positive effects. Amylase responded negatively to Hg2+, positively to Zn2+, and showed mixed response to Cd2+. AP levels decreased under metal stresses, except Zn2+.