Specific activity of nitrite reductase
The specific activity values shown in Figure 10 are the average of two specific activities calculated for
each treatment. Specific activity of nitrite reductase in 0.5 mM plants was more followed by 0.1 mM,
0.05 mM and control plants. NiR activity of control plants and 0.05 mM treated plants increased up to
30 days and then a decline was observed. Accumulation of nitrite becomes toxic for the plants and it
should be converted immediately to ammonia by the enzyme nitrite reductase as and when nitrite is
formed from nitrate. Our results indicate that uptake of nitrate occurred up to 30 days and then gradually
decreased. Similarly, specific activity of 0.1 mM plants and 0.5 mM plants increased up to 45 days
and then showed a decrease. This suggests that uptake of nitrate occurs for a longer period in these
plants as vegetative period is longer.