NaCl胁迫对三种胡颓子属植物幼苗活性氧清除酶与渗透调节物质含量的影响

为研究胡颓子属植物的耐盐性,以三种胡颓子属植物一年生幼苗为材料,在不同浓度的NaCl胁迫(0,50、100、200、300和350 mmol/L)处理30 d后,测定其叶片的膜脂过氧化产物、活性氧清除酶活性和渗透调节物质含量的变化。结果显示,在NaCl胁迫下,三种胡颓子属植物叶片的膜透性、MDA和H2O2含量均随NaCl浓度的升高而增加,表明NaCl胁迫致使胡颓子属植物膜脂过氧化程度加强,细胞膜稳定性受到破坏,其中东方沙枣的膜透性和MDA含量增加幅度较大,受到的盐害较大。而三种胡颓子属植物经受30 d盐胁迫后,其叶片中活性氧清除酶的活性变化似乎存在着不同的特性,在盐胁迫下除东方沙枣叶片SOD活性比对照低以外,其余的活性氧清除酶的活性始终高于对照,但变化幅度不一致;脯氨酸和可溶性糖含量随着胁迫程度的加重而不断增加,其中尖果沙枣叶片中的脯氨酸含量成倍增长,且可溶性蛋白含量缓慢增加,而大果沙枣与东方沙枣叶片可溶性蛋白含量先减后增的趋势。总之,NaCl胁迫下三种胡颓子属植物幼苗各项指标变化幅度的综合比较,尖果沙枣相对大果沙枣和东方沙枣显示较强的耐盐能力。

Effects of NaCl Stress on Reactive-Oxygen-Scavenging Enzymes and Contents of Osmotic Adjustment Substances in Leaves of Three Species Oleaster Plants Seedlings

In this experiment,one year old seedlings of three species oleaster plants were grown in pots and were treated with NaCl at different concentrations(0,50,100,200,300 and 350 mmol/L)for 30 days and lipid peroxidation,the activities of reactive oxygen scavenging enzymes and contents of osmotic adjustment substances in leaves were measured and compared,in order to study the salt tolerance of oleaster plants.The experimental results showed that the membrane permeability,MDA and H2O2 content in the leaves of three species oleaster plants increased considerably with the increasing NaCl stress,which aggravated the degree of membrane lipid peroxidation and the cell membrane stability was injured.The membrane permeability and MDA content in E.angustifolia var orientalis Kuntze increased more quickly than the other two species and thus experienced greater damage at higher NaCl concentrations.After three species of oleasters undergo salt stress for 30 days,the change of reactive-oxygen-scavenging enzyme activities seemed to be in different characteristic,reactive-oxygen-scavenging enzyme activities of three species of oleaster plants were higher than that of control at all the time of treatment,but the range of variety was inconsistent,except that the seedlings of E.angustifolia var orientalis Kuntze decreased their SOD activity.The proline and soluble sugar content in leaves increased with the increase of NaCl concentration.The proline content in leaves of E.oxycarpa Schlecht increased by many times among them and soluble protein content slowly increased,while soluble protein content of Elaeagnus moorcroftii Wall ex Schlecht and E.angustifolia var orientalis Kuntze increased at first and then decreased.In summary,in comparison with the range of allindex variety under NaCl stress,E.oxycarpa Schlecht has greater salt tolerance than Elaeagnus moorcroftii Wall ex Schlecht and E.angustifolia var orientalis Kuntze.