水分条件对豌豆保护酶活性及膜脂过氧化的影响

为探讨不同水分条件对豌豆保护酶系统和膜脂过氧化的影响,采用盆栽人工控水试验方法,模拟干旱胁迫及复水条件,研究了不同水分处理对花荚期豌豆叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及过氧化产物丙二醛(MDA)含量和脂膜相对透性(RC)的影响,并对花荚期豌豆抗氧化能力进行了综合评价.结果表明:不同程度干旱胁迫历时5 d时并未影响豌豆叶片SOD、CAT活性,但有明显的滞后效应.重度干旱胁迫历时10 d可显著降低豌豆叶片SOD、CAT活性,显著提高MDA含量.不同程度的干旱胁迫均导致豌豆叶片POD活性提高,膜脂相对透性加大.复水可对干旱胁迫所造成的CAT、POD活性变化产生显著补偿作用,对SOD活性变化产生超补偿作用.同时,可显著降低MDA含量和脂膜相对透性;干旱胁迫历时10 d内和复水历时10 d内,豌豆有较强的抗氧化能力,仅在重度胁迫10 d后复水历时达到10 d时抗氧化能力趋弱.

Effect of soil water on protective enzyme activity and membrane lipid peroxidation in pea

A pot experiment was conducted to investigate the effect of soil water on protective enzymes of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), and also on membrane lipid peroxidation including malonaldehyde (MDA) and plasma membrane permeability (RC) in pea (Pisum sativum Linn.) leaf during flowering and pod-bearing stages under drought stress and water recovery conditions. Antioxidant ability of pea during flowering and pod-bearing stages was also analyzed. The results indicate that SOD and CAT activity is not significantly influenced by 5-day drought stress with only obvious time lag, but significantly decreases under 10-day drought stress condition. Leaf MDA content increases significantly under 10-day high drought stress. POD activity and leaf RC increase under drought stress. Water recovery has a considerable compensation effect on CAT and POD activity, but also leads to over-compensation effect on SOD activity. Meanwhile MAD content and RC level decrease notably. Pea has strong oxidation resistance within 10 days of drought stress and water recovery. The resistance capacity decreases only under 10-day severe drought stress and water recovery.