UV-C对紫杉针叶叶绿体膜脂过氧化及PSⅡ电子传递活性的影响

Effects of ultraviolet-C irradiation on membrane lipid peroxidation and activity of PSⅡ electron transport in chloroplasts of Taxus cuspidata needles

在实验室条件下 ,用 1 2W·m- 2 剂量的紫外线C(UV C ,2 54nm)辐射紫杉针叶离体叶绿体 .结果表明 ,随辐射时间的延长 ,活性氧清除系统中类胡萝卜素 (Car)、谷胱甘肽 (GSH)含量和超氧化物歧化酶(SOD)活性有不同程度的下降 ;脂质过氧化产物丙二醛 (MDA)含量和膜相对透性有不同程度的增加 ;光系统Ⅱ (PSⅡ )电子传递活性显著下降 ,这种下降与光合活性光 (PAR)强度呈反比 ;叶绿素对UV C辐射不敏感 .根据以上结果推测 ,UV

The isolated chloroplasts of Taxus cuspidata needles treated with 12 W·m -2 of ultraviolet C (UV C, 254 nm) irradiation were studied under laboratory conditions. The results showed that with the increase of UV C irradiation, the carotenoids (Car) and glutathione (GSH) contents and superoxide dismutase (SOD) activity were decreased, while the malondialdehyde content (MDA) and the relative permeability of chloroplasts membrane were increased to various extents. The PSⅡ electron transport activity was conspicuous decreased, which had a significant inverse ratio with photosynthetically active radiation(PAR). UV C irradiation was insensitive on chlorophyll. The results indicated that membrane lipid peroxidation of chloroplasts caused by UV C radiation was the reason of the decrease of PSⅡelectron transport activity.