Plant Physiology Laboratory Department of Botany, University of Calcutta, Calcutta-700019
* Present address: Department of Botany, University of Dhaka, Dhaka 1000, Bangladesh
Treatments with four different concentrations of lead nitrate, viz., 1,4, 7 and 10 mM as foliar spray at five different stages of plant growth (28, 35, 42, 49 and 56 days after sowing) on mungbean resulted in progressive stimulation in the activities of catalase and ascorbic acid oxidase. About 80% stimulation in catalase activity by 10 mM dose was observed at the first stage. This pattern of increment with increasing doses of lead nitrate continued but the rate of increment was more pronounced in the following stages. Similarly ascorbic acid oxidase activity progressively increased with increasing concentrations of lead nitrate up to 10 mM. As the plants grew older, this increasing trend became more pronounced.
