Abstract

Effect of silicon on the activity of peroxidase, polyphenol oxidase and nitrate reductase in cowpea and wheat

Author(s): N.C.Aery, Manju Mali

Nutrient culture experiments were conducted to study the effect of various doses (25, 50, 100, 200, 400 and 800 µg g-1) of silicon on the activity of certain enzymes (peroxidase, polyphenol oxidase and nitrate reductase) in the leaves of wheat and cowpea. Lower doses of silicon (25-200 µg g-1) significantly decreased the activity of peroxidase and polyphenol oxidase enzymes. The increasing concentrations of silicon (400-800 µg g-1) resulted in a concomitant increase in the activity of peroxidase and polyphenol oxidase in both the test crops. Nitrate reductase showed a different trend from that of peroxidase and polyphenol oxidase in both the test crops. A significant increase in nitrate reductase activity was observed at lower additions of silicon whereas higher doses of silicon (400-800 µg g-1) resulted in a decrease in nitrate reductase activity in both the test crops suggesting the involvement of Si in the enzymatic activities of plants.