增强UV-B辐射对小麦叶中CAT、POX和SOD活性的影响

THE EFFECT OF ENHANCED UV B RADIATION ON THE ACTIVITIES OF SOD,CAT AND POX IN WHEAT LEAVES

摘要: 研究了0(CK)、8.82 kJ/ m²(T₁)和12.6 kJ/m²(T₂)三种剂量的紫外线B(UV-B,280～320 nm )辐射对温室种植的小麦膜伤害的机理。试验结果表明,在增强UV-B辐射下,与对照相比,膜脂过氧化产物--丙二醛(MDA)含量明显升高,同时膜脂脂肪酸组成配比改变,不饱和度指数(IUFA)有所下降,并具剂量效应；过氧化氢酶(CAT)、过氧化物酶(POX)活性显着升高,而超氧歧化酶(SOD)活性没有明显的改变。根据上述结果推测,UV-B辐射诱导的植物伤害可能是因膜脂过氧化作用造成对植物膜系统的破坏引起的,其中活性氧自由基可能参与了这一过程。然而,植物存在内在的抗性机制,如通过SOD、CAT、POX活性的改变,可以消除UV-B胁迫的影响

Abstract: The damage mechanisms of UV B radiation with the different dose of 0 (CK),8 82 kJ/m² (T₁) and 12.6 kJ/m² (T₂) in wheat leaves were studied under greenhouse conditions.The MDA content was increased,while IUFA decreased comparing with cotrol.CAT and POX activities were significantly enhanced during exposure to UV B radiation.SOD activity,however,was almost unchanged.The results suggest that lipid peroxidation is one of the causes of membrane damage, where activated oxygen was probably involved in this process,but plants have some intern resistant mechanisms to protect from UV B induced damage.