摘要： 为了研究硝酸盐胁迫对玉米幼苗生长相关酶活性的影响,在前人研究工作的基础上以郑58、郑单958和昌7-2为研究材料,采用溶液培养方法,在不同浓度硝酸盐胁迫下,对3个品种的幼苗进行硝酸还原酶、谷氨酰胺合成酶、超氧化物歧化酶活性的测定。揭示了玉米幼苗在适宜、高、低浓度硝酸盐供应条件下3种酶活性的变化。结果显示:硝酸盐浓度2.00 mmol/L时,根系和叶片的超氧化物歧化酶活性较低,说明该浓度范围可以作为玉米幼苗适宜培养浓度。低(0.02,0.20 mmol/L)、高(10.00,20.00 mmol/L)浓度硝酸盐条件下,SOD活性明显上升,杂交系郑单958体内SOD活性明显高于亲本郑58和昌7-2品种 (P< 0.05),说明郑单958品种在胁迫条件下有较高的自我保护作用。低硝酸盐浓度(0.02,0.20 mmol/L)时,随着硝酸盐供应浓度的增加硝酸还原酶和谷氨酰胺合成酶活性增强;高硝酸盐浓度(10.00,20.00 mmol/L)时,硝酸还原酶和谷氨酰胺合成酶活性下降。叶片NR活性下降程度小于根系,说明硝酸盐供应变化对根系影响较大。父本昌7-2对硝酸盐的还原作用明显弱于母本郑58和子代郑单958,尤其在胁迫条件下存在显著差异(P值均 <0.05)。谷氨酰胺合成酶的变化趋势与硝酸还原酶活力基本相似。

关键词: 玉米, 硝酸盐胁迫, 硝酸还原酶, 谷氨酰胺合成酶, 超氧化物歧化酶

Abstract: In order to understand the effect of nitrate stress on nirtogen assimilation related enzyme activity of maize,on the basis of previous research,Zheng 58,Zhengdan 958 and Chang 7-2 as study materials,under the nitrate stress of different concentrations,nitrate reductase,glutamine synthetase,measuring superoxides dismutase activity were analyzed using solution culture method.It was revealed that changes of three enzymes activity of maize seedlings at suitable,high,low concentrations of nitrate supply conditions.The results showed that SOD activity of roots and leaves were low when nitrate concentration was 2.00 mmol/L,indicating that the concentration range was suitable for maize seedlings.Low (0.02,0.20 mmol/L),high (10.00,20.00 mmol/L) at a concentration of nitrate conditions,SOD activity was significantly increased in vivo hybrids Zhengdan 958,which was significantly higher than SOD activity of the parental species Zheng 58 and Chang 7-2 (P <0.05).It showed that Zhengdan 958 varieties had a higher self-protection role under stress conditions.With the increasing concentration of nitrate supply NR and GS activity were increased at low concentration of nitric acid (0.02,0.20 mmol/L),At high nitrate concentrations (10.00,20.00 mmol/L),NR and GS activity were decreased.NR activity of leaves decreased less than the root,indicating greater nitrate supply changed in the root.The reduction of nitrate of paternal Chang 7-2 was significantly weaker than the female offspring Zheng 58 and Zhengdan 958 and in particular it was significant differences (P <0.05) under stress conditions.GS trends and NR enzyme activity were similar.

Key words: Zea mays L., Nitrate stress, Nitrate reductase, Glutamine synthetase, Superoxide dismutase (SOD)

中图分类号: 

• S513