玉米叶片硝酸还原酶活性测定方法的优化

以玉米(Zea mays L.)自交系许178为材料,通过考察研磨方法、NADH用量、温度、pH、反应时间、显色时间对玉米叶片硝酸还原酶活性的影响获得最优试验条件。结果表明,石英砂研磨比液氮研磨测得的酶活性高;反应温度35℃、pH 7.5为较适反应条件;反应时间和显色时间均为10 min时测得的硝酸还原酶活性与标准方法相比无显著差异;还原剂NADH用量减少至一半测得的硝酸还原酶活性与标准方法无显著差异。综上所述,玉米叶片硝酸还原酶活性测定的优化处理方案为用石英砂研磨,加入0.15 m L NADH,在35℃、pH 7.5的条件下反应10 min,显色10 min。

Optimization of the Determination Method for the Nitrate Reductase in Maize Leaves

In order to get the optimal experimental conditions,taking maize (Zea mays L.) inbred lines Xu178 as material,the effects of grinding methods,dosage of reductant NADH,reaction temperature,reaction time,pH and color developing time on nitrate reductase of maize leaves were studied.The results showed that Quartz sand grinding has higher activity than liquid nitrogen.The optimal reaction temperature was 35 ℃ and the optimal pH value was 7.5.There were no significant differences between the standard method and the reaction conditions that reaction time and coloration time were both 10 min,and also no significant differences between the half dosage of the reducing agent NADH and the standard method's dosage.In conclusion,the optimal experimental conditions to assay nitrate reductase activity of the maize leaves were that Quartz sand grinding,the reaction temperature was 35 ℃,the pH value was 7.5,the reaction time was 10 min,the color developing time was 10 min and dosage of reductant NADH was 0.15 mL.