Na_2CO_3胁迫对碱地风毛菊苗期叶片和根系氮代谢的影响

Effects of Na_2CO_3 stress on key indicators of nitrogen metabolism of Saussurea runcinata at seedling stage

对碱地风毛菊苗期以Na2CO3进行胁迫处理,浓度为0、30、60、90、120、150和180 mmol/L,测定了盐胁迫下叶片和根系氮代谢过程的可溶性蛋白、硝酸还原酶、硝态氮及谷氨酰胺合成酶等指标。结果表明:在Na2CO3胁迫下,碱地风毛菊叶片和根系可溶性蛋白含量均在120 mmol/L处理下达到最大值,为6.76和6.75 mg/g.FW,且与对照差异显著(P<0.05);随Na2CO3浓度增大,叶片的硝酸还原酶活性下降,根系的先下降后升高,根系硝态氮含量先增加后下降,叶片谷氨酰胺合成酶活性变化不明显,与对照差异不显著,根系的呈上升趋势,与对照差异显著(P<0.05)。

Key indicators of nitrogen metabolism of Saussurea runcinata at seedling stage under Na2CO3 stress（0,30,60,90,120,150 and 180 mmol/L）were determined.It has been shown that the soluble protein content and GS（Glutamine synthetase）activity of Saussurea runcinata at seedling stage increased under Na2CO3 stress.The soluble protein content of leaves and roots reached 6.76 and 6.75 mg/g·FW respectively,which were the maximum under the concentration of 120 mmol/L,and the GS activity all reached the maximum under the concentration of 180 mmol/L,GS activity in leaves was 1.38 times than control and 1.85 times than control in roots,GS activity in roots when the maximum was 1.65 times than in leaves,but NR（Nitrate reductas）activity decreased,the minimum was 5.44 μg/（g·h）.The use efficiency of NO3-N in Saussurea runcinata at seedling stage decreased,but the use efficiency of ammonia nitrogen increased,ammonia nitrogen was the main source of nitrogen to Saussurea runcinata seedling growth.