梭梭属植物抗氧化酶活性对荒漠环境的季节性响应

Seasonal Response of the Activity of Antioxidant Enzymes of Haloxylon Bunge to Desert

以生长在中国科学院吐鲁番沙漠植物园荒漠干旱胁迫下的梭梭属植物为研究对象,结合地下水位变化及高温持续天数,定期测定生长季内梭梭属植物同化枝抗氧化酶活性的变化。结果表明：在干旱胁迫初期（4,5月）,梭梭属植物同化枝内超氧化物歧化酶（SOD）和过氧化物酶（POD）活性明显增加,随着地下水位的下降和持续高温时间的延长（6-8月）,超氧化物歧化酶和过氧化物酶活性继续增高,在生长季末期（9,10月）胁迫减弱时又缓慢降低;而过氧化氢酶（CAT）活性在6-8月随着持续高温时间的延长和胁迫强度的增加,其活性急剧下降直至为0。在整个生长季内,梭梭和白梭梭超氧化物歧化酶和过氧化物酶对高温干旱反应敏感;白梭梭超氧化物歧化酶活性高于梭梭,表明梭梭抗旱性比白梭梭强。

This paper aims at Haloxylon Bunge（H.ammodendron and H.persicum）in the desert of periphery of Turpan Eremophytes Botanic Garden,Chinese Academy of Science,under drought stress,combining variations of groundwater level and the continuous days of high temperature of Turpan Eremophytes Botanic Garden,from March to the end of August,regularly determining change of activity of antioxidant enzymes of assimilational twig of Haloxylon Bunge.The result indicated that：At the initial stage of dry stress（from Apr.to May）,the activity of SOD and POD was accumulated rapidly.With the increase of dry stress（from Jun.to Aug.）,activity of SOD and POD was increased continuously.At the end of growth season（from Sep.to Oct.）,activity was decreased.While with the increase of dry stress（from Jun.to Aug.）,activity of CAT was decreased rapidly to zero.Under the same ecological environment,the activity of SOD and POD are sensitive to the change of the groundwater level and the continuous days of high temperature,and the activity of SOD of H.persicum is significantly higher than that of H.ammodendron.So H.ammodendron had stronger drought-resistance than H.persicum.