二氧化硫胁迫对玉米幼苗叶片膜脂过氧化和抗氧化酶的影响

Effects of Sulfur Dioxide Hydrate Stress on Lipid Peroxidation and Activities of Antioxidant Enzymes in Leaves of Maize Seedlings

利用NaHSO3处理玉米幼苗模拟水相SO2胁迫,比较分析了BT-1(抗)、N6(感)自交系经NaHSO3胁迫后细胞膜脂过氧化和几种抗氧化酶活性的动态变化。结果表明:随着水相SO2胁迫时间的延长,高感系N6叶片中丙二醛(MDA)含量和H2O2积累量比高抗系BT-1显著增加;抗、感系中抗氧化酶超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性都有明显的增强,而过氧化氢酶(CAT)的活性呈显著下降趋势。说明H2O2的积累导致玉米叶片膜脂过氧化加剧,SOD和APX在玉米遭受SO2胁迫中起着重要的保护作用。

Dynamic changes of lipid peroxidation and activities of antioxidant enzymes were analyzed in leaves of maize seedlings of resistant inbred BT-1 and susceptible inbred N6 by simulating sulfur dioxide hydrate stress using NaHSO3 treatment. The results showed that MDA content and H2O2 accumulation level in susceptible inbred BT-1 increased significantly compared to those of resistant inbred N6 in the time course of 5 mmol/L NaHSO3 treatment. The activities of SOD and APX in both of the inbred lines were enhanced remarkably, whereas the activity of CAT in the two lines decreased continuously. These results suggested that H2O2 accumulation could increase severity of lipid peroxidation and antioxidant enzymes SOD and APX may play an important role in protecting maize plants against sulfur dioxide toxicity.