淹水胁迫对喜树幼苗LDH及保护酶的影响

研究淹水胁迫下1年生喜树根系活力、根系乳酸脱氢酶(LDH)及叶片保护酶活性和活性氧代谢的变化规律。结果表明:根系活力在淹水处理后期急剧下降,LDH活性随淹水时间的延长和强度的加大而升高。轻度淹水胁迫下,喜树叶片内过氧化物酶(POD)和超氧化物岐化酶(SOD)活性保持较平稳的水平,能够有效地清除活性氧自由基,使之维持在较低水平;重度淹水胁迫下,随胁迫的持续,叶片POD和SOD活性先升高后降低,在胁迫后期不能有效地清除活性氧,导致叶片膜脂的过氧化作用加剧,丙二醛(MDA)大量积累,植株遭到伤害。

Effects of waterlogging on LDH and protective enzyme in Camptotheca acuminata seedling

The changes of root activity,lactate dehydrogenase(LDH),protective enzyme activity and reactive oxygen species of Camptotheca acuminata seedling under different flooding stresses were investigated in this experiment.The results showed that in the late stage of waterlogged stress,root activity decreased dramatically,LDH decreased under different degree and time of stress;peroxidase(POD) and superoxide dismustase(SOD) changed more significantly.In mild flooding stress,SOD and POD activity could remain stable at a relatively high level,the activity increased first and then declined with the stress time extension in severe flooding stress.In the later stage the capability to clear reactive oxygens tended to be less effective,thereby leading to the leaf lipid peroxidation degree higher,accumulating more malondialdehyde(MDA) in the leaves,causing injury to the seedlings.