高温胁迫对黄连幼苗活性氧代谢及保护酶活性的影响

目的]研究高温胁迫对黄连幼苗活性氧代谢及保护酶活性的影响。方法]以黄连为材料，研究了其在（35±2）℃高温胁迫下相关生理生化指标的变化情况。结果]高温胁迫后，黄连叶片内丙二醛（MDA）含量明显高于对照（P〈0．05）；超氧阴离子（O2）清除速率下降，且胁迫6d后其清除速率已极显著低于对照（P〈0．01）；羟自由基（OH·）的产生速率则显著高于对照（P〈0．05），但随胁迫时间的延长，其在不同生长期幼苗叶片内的变化不规律；胁迫过程中POD酶活性的变化和OH·的变化规律一致；不同生长期SOD酶活性随着胁迫时间的延长而降低。结论]黄连可以通过调节POD酶和SOD酶的活性来减小高温胁迫造成的伤害，但随着胁迫时间的增长，这种能力逐渐变小。

Effect of High Temperature Stress on Active Oxygen Metabolism and Activities of Protective Enzymes of Coptis chinensis Franch.Seedling

Objective] To study the effect of high temperature stress on active oxygen metabolism and activities protective enzymes of Coptis cheinensis Franch.seedling.Method] The correlative physiological and biochemical indices were determined when Coptis chinensis Franch.was under the high temperature(35±2) ℃.Result] When suffering high temperature stress,Coptis chinensis Franch.was significant higher in MDA in comparison with CK(P<0.05).Under the high temperature stress,the scavenging rate of superoxide anion decreased,which was highly significant lower than that in CK(P<0.01),and the generating rate of hydroxyl radical was significant higher than that in CK(P<0.05),but it did not vary as certain rule,the same as activity of POD.Moreover,activity of SOD in Coptis cheinensis Franch.of different growth period decreased with the increase of stress duration.Conclusion] Coptis cheinensis Franch.had the ability that regulated the POD and SOD activities to reduce the injury degree produced by the high temperature stress,which,however,was reduced with the increase of high temperature stress duration.