外源物质对干旱胁迫下麻黄幼苗膜质过氧化作用的影响

Effects of Exogenous Substances on Membrane Lipid Peroxidation of Ephedra sinica Seedlings Under Drought Stress

以麻黄幼苗为试材,利用PEG-6000人工模拟干旱胁迫,采用盆栽灌根法,研究了腐殖酸、外源硝普钠(SNP)、甜菜碱处理下麻黄幼苗的可溶性蛋白质、丙二醛(MDA)含量及抗氧化酶活性的变化。结果表明:干旱胁迫下,麻黄幼苗MDA含量显著升高,可溶性蛋白质含量及过氧化物酶(POD)、过氧化氢酶(CAT)活性降低,超氧化物歧化酶(SOD)活性升高;对比干旱胁迫,外源物质处理下MDA含量明显降低,可溶性蛋白质及抗氧化酶活性明显增加,且随处理浓度增加均呈现先升后降的规律,随处理时间的有所增加。综合表明,2.5mmo1·L^(-1)的甜菜碱处理10d为缓解氧化损伤效果的最佳处理,此外100mL·L^(-1)的腐植酸、0.25mmo1·L^(-1)的SNP也有效地缓解了麻黄干旱胁迫,3种外源物质不同程度地提高了麻黄幼苗的抗旱能力,为干旱半干旱地区麻黄的推广栽培提供了依据。

Ephedra sinica seedlings were used as the experimental materials,drought stress was simulated with PEG-6000,the plate culture with irrigation method was used to determine contents of solue protein,MDA and antioxidant enzyme activity in Ephedra sinica seedlings under HA,exogenous SNP,betaine.The results showed that the contents of MDA raised significantly,the contents of solue protein,activities of POD and CAT reduced,while the activity of SOD increased;in contrast to drought stress,the contents of MDA descended obviously,the contents of solue protein and antioxidant enzyme activity increased significantly under treatments of exogenous substances.The above indexes raised firstly,then decreased with the increase in concentration of exogenous substances and increased gradually at last during treating time.The comprehensive results showed that the treatments of 2.5 mmo1·L-1 betaine and 10 days treatment time was the best to relief membrane lipid peroxidation,meanwhile the treatment of 100mL·L-1 HA and 0.25mmo1·L-1 SNP relieved the drought stresses effectively,the drought resistance was advanced in some degree of Ephedra sinicaseedlings under three exogenous substances,it provided a basis for extend culture of Ephedra sinicain arid and semi-arid areas.