Effects of Low Nitrogen Stress on Activities of Protective Enzymes of Ultrahigh-Yield Maize

Effects of low nitrogen stress on activities of protective enzymes of maize leaf were studied.The results showed that: Under low nitrogen stress,MDA content in plant species changed greatly;CAT and POD activities changed greatly,showing a single peak curve,and in the normal nitrogen treatment level,CAT activities were the highest,and decreased with the decrease of nitrogen;In the no nitrogen treatment level,POD activities were the highest,but decreased with the increase of nitrogen.The SOD activity was the opposite,and although the changes showed a single peak,it increased with the increase of nitrogen.Under the low N stress conditions,activities of protective enzymes of zhengdan 958 and xianyu 335 were higher,MDA was lower,anti-aging ability and the ability to adapt to the environment were higher,and leaf senescence was slower.