Ameliorative role of certain naturally occuring protective substances in antagonising the phytotoxic effects of copper sulphate on nitrate reductase activity in Pisum Sativum L.

The present investigation was carried out in the winter season of 2002–2003 to study the nitrate reductase (NR) activity in terms of soluble protein in the leaves of Pisum sativum as influenced by different concentrations of CuSO₄. Nitrate reductase activity was inhibited with increasing concentration of CuSO₄ (0.01, 0.05, 0.1 and 1 mM). Use of plant growth regulators (PGRs), viz. IAA, GA₃ and kinetin and certain protective substances, such as EDTA (0.1M), methionine (1.0 mM), sucrose (5 mM), phosphorus (KH₂PO₄ 5 mM) and KNO₃ (5 mM) in combination with least inhibitory concentration of copper sulphate (0.01 mM) were found to increase nitrate reductase activity in the leaves of Pisum sativum L.