模拟干旱胁迫对枣树幼苗的抗氧化系统和渗透调节的影响

用不同浓度的PEG-6000对抗旱性不同的1年生枣树(Zizyphus jujuba)幼苗进行渗透胁迫处理后,研究了不同抗旱性品种枣树幼苗的抗氧化酶活性和渗透调节物质含量的变化.结果显示,干旱胁迫下3种枣苗叶片的相对含水量(RWC)均降低,丙二醛(MDA)含量和细胞质膜相对透性均增加.在30%PEG胁迫下除骏枣1号的SOD活性降低外,3个品种枣苗在干旱胁迫下SOD和POD活性都增加;狗头枣2号的过氧化氢酶(CAT)活性在胁迫下明显增加,而木枣1号和骏枣1号的CAT活性均随着胁迫程度的增加而逐渐下降;木枣1号和骏枣1号的APX活性随着胁迫程度的增加先增加后降低,而狗头枣2号明显增加.干旱胁迫下,除骏枣1号的脯氨酸(Pro)含量和木枣1号的可溶性糖含量在30%的胁迫水平下降低(P>0.05)外,3种干旱胁迫水平下3个品种枣苗的Pro和可溶性糖含量均增加.总之,干旱胁迫下,枣苗叶片相对含水量、抗氧化酶(SOD、POD、CAT和APX)活性、渗透调节物质Pro和可溶性糖含量均为:狗头枣2号>木枣1号>骏枣1号,而MDA含量和膜透性均为骏枣1号>木枣1号>狗头枣2号,表明3个品种的抗旱性为:狗头枣2号>木枣1号>骏枣1号,研究结果与其品种的实际抗旱性一致.

Effects of Simulated Drought on Antioxidative Enzymes and Osmotic Regulation in Zizyphus jujuba Seedlings

One year old seedlings of Zizyphus jujuba with different drought resistances were treated with PEG-6000 at different concentrations to study the activities of antioxidative enzymes and the contents of osmosis-regulating substances in the seedlings of different Zizyphus jujuba varieties with different drought resistances.It was shown that under the simulated drought,the seedlings of the three varieties decreased the relative water contents and the MDA contents,and increased the relative permeability of cytoplasmic membrane in their leaves.Under the drought simulated with 30% PEG,the seedlings of three varieties increased their SOD and POD activities except that the seedlings of 'Junzao 1' decreased their SOD activity;the seedlings of 'Goutouzao 2' remarkably increased their CAT activity and the seedlings of 'Muzao 1' and 'Junzao 1' gradually decreased their CAT activities as the simulated drought become intensified;as the simulated drought became intensified,the seedlings of 'Muzao 1' and 'Junzao 1' first decreased their APX activities and then decreased the activities,the seedlings of 'Goutouzao 2' remarkably increased their APX activity.Under the drought simulated with PET at 30%,the seedling of 'Junzao 1' increased their proline content and the seedlings of 'Muzao1' increased their soluble sugar contents(P>0.05) and under the three droughts simulated with PEG at the three different concentrations,the seedlings of the three varieties increased their proline and soluble sugar contents.In summary,the relative water contents and the activities of anti-oxidative enzymes(SOD,POD,CAT and APX) and the contents of osmosis-regulating proline and soluble sugar of the three varieties are in the order of 'Goutouzao 2'>'Muzao 1'>'Junzao 1' and the MAD contents of the three varieties were in the order of 'Junzao 1'>'Muzao 1'>'Goutouzao 2';And this showed that the resistances of the three varieties were in the order of 'Goutouzao 2'>'Muzao 1'>'Junzao 1',as they are arranged in reality.