Effect of rewatering on activity of protect enzymes and membrane peroxidation in Robinia. pseudoacacia seedling | 旱后复水对刺槐苗木叶片保护酶活性和膜质过氧化的影响

chinois. 研究刺槐苗木在较长时间处于水分胁迫以及解除胁迫之后的生理动态变化，对旱后复水激发刺槐的生理学补偿效应机制进行初步探讨。以1年生的刺槐苗木为材料，采用盆栽试验，以土壤相对含水率（SRW）为100.00%的处理为对照，探讨不同水分胁迫强度(土壤相对含水率87.84%，70.00%，52.16%，40.00%)胁迫30 d 时以及复水2，24，48和72 h后，刺槐叶片超氧化物歧化酶(SOD）、过氧化物酶(POD）活性及超氧阴离子自由基(•O-2)和丙二醛（MDA)含量的变化。水分胁迫30 d后，随着水分胁迫程度的加深，刺槐叶片中•O-2和丙二醛含量均明显高于对照，同时SOD和POD活性明显提高，仍能维持较强的活性氧清除能力，其中SRW为40.00%的处理刺槐叶片SOD和POD活性较SRW为52.16%的处理低，但均高于对照。旱后复水2 h，SOD和POD活性急剧上升，•O-2和MDA含量下降幅度较大。旱后复水72 h，经过水分胁迫后的刺槐叶片抗氧化酶体系清除超氧阴离子自由基能力较对照得到加强。适度水分胁迫使刺槐苗木的抗氧化能力得到加强。

anglais. Physiological changes during water stress and rewatering in Robinia pseudoacacia seedling leaves were studied to investigate the compensation effect that was woken by water stress. A potted experiment was conducted in 30 days and with 5 different soil relative water content (SRW) levels, which were 100.00%, 87.84%, 70.00%, 52.16% and 40.00%. The activities of superoxide dismutase (SOD) and peroxidase (POD), the content of superoxide hydronium（•O-2）and malondialdehyde (MDA) in leaves of one-year-old R. pseudoacacia were tested under different water stress levels and 2, 24, 48, 72 h later after rewatering. During the same period of water stress, the content of superoxide hydronium(•O-2) and malondialdehyde (MDA) rose significantly compared with control treatment. Meanwhile the activities of superoxide dismutase (SOD) and peroxidase (POD) were boosting and could still maintain at a high level of active oxygen eliminating. The activities of superoxide dismutase (SOD) and peroxidase (POD) were lower in SRW of 40.00% than that of 52.16%, but still higher than that of control treatment. The activities of superoxide dismutase (SOD) and peroxidase (POD) soared, however the content of superoxide hydronium (•O-2) and malondialdehyde (MDA) declined quickly 2 h after rewatering. The active oxygen eliminating ability of protect enzymes in leaves of R. pseudoacacia seedling was strengthened by water stress compared with control treatment. The antioxidation ability could be strengthened by proper water stress in R. pseudoacacia seedling.