远紫外辐射对紫杉幼苗针叶膜脂过氧化及内源保护系统的影响

实验室条件下用远紫外线（ＵＶ－ＢＣ）光源照射紫杉幼苗，随照射时间延长、针叶的离子渗出率、膜脂过氧化水平、组织自动氧化快速率及Ｈ２Ｏ２含量显著增加，可溶性蛋白、抗坏血酸、类胡萝卜素和叶绿素含量下降，叶绿体光系统ＩＩ电子传递活性显著下降，外源活性氧清除剂苯甲酸钠和抗坏血酸对针叶膜脂过氧化有抑制作用；甲基紫精和ＤＤＣ对针叶膜脂过氧化有促进效果，远紫外线引起的紫杉伤害可能和针叶树的越冬光氧化伤害有类似之处

Effect of far-ultraviolet radiation on lipid peroxidation and inherent protection system in seedlings of Taxus cuspidata

The effect of far ultraviolet radiation on lipid peroxidation and inherent protection system in seedlings of Taxus cuspidata was examined with simulated UV BC irradiation treatments. The electrolyte leakage, lipid peroxidation, tissue autoxidation and H 2O 2 content increased,while the contents of soluble protein, ascorbic acid, carotenoids, and chlorophyll and the photosynthetic electron transport rate of Photosystem II decreased with the increasing time of treatment. The lipid peroxidation of the needles was inhibited by exogenous scavengers sodium benzoate and ascorbate, but enhanced to some extent by methyl viologen and DDC (an inhibitor of SOD). The mechanisms of the injury of the seedlings induced by UV BC radiation might be similar to that of photooxidation injuries of conifers in winter. However, Taxus cuspidata was much more resistant to UV BC radiation than crops.