Ribonuclease activity of Glycine max and Glycine soja sprouts as a marker adaptation to copper sulphate and zinc sulphate toxicity

Abstract

Environmental pollution caused by anthropogenic activities has increased agricultural land contamination with heavy metals which is harmful to plant and human health. Increased metal accumulation in the soils may trigger competition between toxic metals and essential nutrients for absorption by plants and consequently leads to the development of oxidative stress. Soybean plants have a delicate system of defense mechanisms. We assume that the influence of heavy metals on plant growth as a whole can be traced through a change in the activity of enzymes. We studied the stress-reducing reaction against the toxic effects of copper sulphate and zinc sulphate, identified different endurance classes, and observed differences in the biochemical adaptation i.e. ribonuclease (RNase) activity in the wild and cultivated soybean sprouts. Sulphates of both zinc and copper at maximum permissible concentration and double maximum permissible concentration affected the multiple forms of RNase and its specific activity in the wild and cultivated soybean sprouts (grown for 1, 3, 5, and 7 days). Wild soybean sprouts had higher RNase activity as compared to cultivated soybean sprouts. It is shown that the limits of endurance for wild soybean during intoxication are observed on days 1, 3 and 5, while for cultivated soybean they vary depending on the type of toxicant and its concentration. Sulphates of copper and zinc affect the wild and cultivated soybean sprouts in a time and dose-dependent manner.