| dc.description |
Nitrite accumulation may result from unbalance between nitrate reductase which produces nitrite and nitrite reductase which removes it. In the first experiment, using three light levels and three nitrate levels, on Lolium, maize, and oats, both enzymes responded to increased light, though not always significantly. The effect of nitrate was more variable. Nitrate reductase activity increased to the intermediate or highest level of nitrate, but there was no clear response in nitrite reductase activity or in nitrite concentration. In the second experiment, using four nitrate levels but only one, high, light intensity on Lolium and barley, the results were clearer. With increasing nitrate supply, nitrate reductase activity increased more than nitrite reductase activity. This was particularly marked in Lolium, in which nitrite accumulated at the highest nitrate supply. Thus high nitrate supply unbalances the two enzymes in the direction leading to nitrite accumulation. |
