NaCl浓度对大米草保护酶活性和渗透调节的影响

Effects of NaCl Concentration on Protective Enzyme and Osmotic Regulation of Spartina anglica

研究不同NaCl浓度下大米草根部和叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、膜脂过氧化产物丙二醛(MDA)、游离脯氨酸及可溶性糖的变化。结果表明:CNaCl等于100 mmol/L时,大米草生长良好;CNaCl高于100 mmol/L时,大米草通过提高SOD、POD和CAT活性,增加游离脯氨酸和可溶性糖含量,以适应NaCl浓度变化;CNaCl达到500 mmol/L后,保护酶活性开始下降,而游离脯氨酸和可溶性糖含量却持续上升,叶片MDA含量亦持续上升,根部MDA却略有下降。在NaCl胁迫下,大米草叶片较根部对NaCl浓度更为敏感。

The contents of superoxide dismutase （SOD） ,guaiacol peroxidase（POD） ,catalase （CAT） ,mal- ondialdehyde （MDA）,soluble sugar and free proline of Spartina anglica under different NaC1 concentration processing were studied. The results showed that：S, anglica grew well when NaCl concentration was 100 mmol/L. When treated with,high NaC1 concentration （higher than 100 retool/L） the growth of S. anglica was inhibited. Meanwhile S. anglica could acclimate to the osmotic pressure created by external solution concentration by adjusting the activities of SOD,CAT and POD as well as the content of free proline, soluble sugar adapt to higher NaCl concentration. The activities of SOD,CAT and POD began to decrease when NaCl concentration reached to 500 mmol/L,however,soluble sugar and free proline kept increasing. Compared to roots,leaves accumulated more soluble sugar and free proline,suggested that leaves were more sensitive to NaCl stress than roots.