Nitrate reductase of rice (Oryza sativa L.) under foot-rot disease.

Studies reported here reveal a low nitrate reductase activity in the shoots of MTU 9 rice plants while in roots high enzyme activity has been recorded.Under pathogenesis, a low nitrate reductase activity in the roots and a high enzyme activity in the shoots have been recorded in susceptible rice plants. In the resistant rice plants (GEB 24) no such marked difference in the enzyme activity has been observed.The effect of fusaric and gibberellic acid on this enzyme activity has been studied. In the case of fusaric acid, the nitrate reductase activity in the roots is inversely proportional to the concentration whereas in gibberellic acid, it is directly proportional to the concentration in the shoots.