Effect of Lead and Cadmium on the Bio-Chemical Changes in the Leaves of Terrestrial (Vigna) and Aquatic (Hydrilla) Plants Under Solution Culture.

The seedlings of the terrestrial plant Vigna catjang Endle and the twigs of the aquatic plant Hydrilla verticillata were treated with PbCl₂ and CdCl₂ (10⁻⁵M each) for 6 days under natural conditions. Chlorophyll a, chlorophyll b and carotenoids declined but chlorophyll a/b ratio increased slightly. Inslouble and total carbohydrate declined in all the cases, where as the soluble carbohydrate declined in Vigna and rose in Hydrilla. Amylase activity increased in all the plants, however the increase was more pronounced in Hydrilla than in Vigna. The activity of the enzymes Protease and RNAse was enhanced in both the plants under heavy metal stress, the enhancement being more marked in cadmium stress than in lead stress.