NaCl胁迫对尖果沙枣实生苗膜脂过氧化与抗氧化酶系的影响

Effects of NaCl stress on lipid peroxidation and activity of antioxidant enzymes in Elaeagnus oxycarpa

以1a生尖果沙枣实生苗为材料进行不同程度的NaCl胁迫处理,研究其细胞膜透性、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的变化。结果表明,在胁迫的不同时期,各处理膜透性的变化呈增加的趋势,且随时间的延长各处理中叶片的膜透性也逐渐增大。整个处理过程中,MDA含量逐渐增加,但增加幅度不大,表明脂质过氧化反应水平较低。各处理中SOD和CAT活性整体上呈增加趋势,其中NaCl胁迫30d,随盐度的加重其活性达到最大值。另外,胁迫20d以内,POD活性随NaCl浓度的升高先增加后下降,并相同的处理中,随着时间的延长有所降低。经相关性分析可知,尖果沙枣的膜透性、MDA含量与抗氧化酶活性之间有一定的关系,表明尖果沙枣细胞膜透性与脂质过氧化产物(MDA)含量有关,也与组织中抗氧化酶活性密切相关。

One-year-old seedlings of Elaeagnus oxycarpa Schlecht. were treated with different concentration of NaCl stress. The changes of the membrane permeability, malondialdehyde content （MDA）, superoxide dismutase （SOD） activity, catalase （CAT） activity and peroxidase（POD） activity of leaves were studied. The results showed that the changes of membrane permeability took on an increasing trend at different stress time under each salt stress treatment. However, membrane permeability was gradually increased with prolonging the NaCl stress time. The malondialdehyde content was increased all the time, but its increase was not so significant, which reveals that the level of membrane liquid peroxidation was low. SOD and CAT activity in leaves of E. oxycarpa Schlecht. under NaCl stress with different concentrations were generally increased, and reached their maximum values with the increase of NaCl concentration when the seedlings of E. oxycarpa Schlecht. were treated 30 days. When NaCl stress was continued in 20 d, POD activity showed increasing firstly and then decreasing with the increasing NaCl stress, and it was reduced with the prolonging of the stress time at the same treatment. The correlation analysis showed that there were significant correlations among the membrane permeability, MDA content and the activity of antioxidant enzymes in leaves of E. oxycarpa Schlecht , which implied that the membrane permeability had a close relation with MDA content and the activity of antioxidant enzymes.