氮素形态和光照强度对菜豆生长和抗氧化酶活性的影响

Effect of light intensity and nitrogen form on the growth and the activities of antioxidative enzymes in French bean.

氮素形态和光照强度对菜豆植株生长和抗氧化酶活性影响的研究结果表明，在弱光下，氮素形态不影响植株生长，但在强光下，铵态氮对植株生长有明显的抑制．铵态氮供应的植株叶片中游离铵含量高于硝酸盐供应的植株．在增加光照强度情况下硝态氮供应植株的抗坏血酸含量高于铵态氮供应的植株；但对脱氢抗坏血酸含量来说，它不受氮素形态的影响．光照强度的增加和铵态氮的供应，都增加依赖于抗坏血酸的Ｈ２Ｏ２清除酶系统（抗坏血酸过氧化物酶、单脱氢抗坏血酸还原酶、脱氢抗坏血酸还原酶和谷胱甘肽还原酶）的活性，但对ＳＯＤ活性影响较小．

The effect of light intensity and nitrogen form on the plant growth and the activities of antioxidative enzymes in the leaves were studied in French bean. The results showed that under low light intensity the plant growth was not affected by nitrogen form, but under high light intensity the plant growth was inhibited by ammonium nutrition. The ammonium content in the leaves was increased by ammonium nutrition, but not influenced by nitrogen form. The ascorbate content was increased by increased light intensity, but decreased by ammonium nutrition. The content of dehydroascorbate was promoted by increased light intensity, but not affected by nitrogen form. The activities of ascorbatedependent H2O2scavenging enzymes were increased by increased light intensity and ammonium nutrition. But the activity of SOD was not affected. There were no significant differences of catalase activity among the treatments.