作　　者： ; ;

机构地区： 兰州大学生命科学学院干旱农业生态国家重点实验室

出　　处： 《植物生理与分子生物学学报》 2003年第2期92-96,共5页

摘　　要： 用Na2 S处理小麦幼苗 ,提高了光呼吸速率 ,减少了O- ·2 的含量 ;用草酸处理 ,降低了光呼吸速率 ,增加了O- ·2 的含量。光呼吸速率的变化与H2 O2 含量无关 ,却与膜脂过氧化水平呈负相关。体外试验表明 :Na2 S和草酸对O- ·2 和H2 O2 没有作用。小麦幼苗中 ,过氧化氢酶活性比乙醇酸氧化酶活性高 3个数量级 ,Na2 S和草酸对乙醇酸氧化酶活性分别有促进和抑制作用 ,却对过氧化氢酶活性没有影响。这些结果表明光呼吸是植物体内防止活性氧积累和伤害的一道防线。 This paper studied the effects of the inhibitor oxalic acid and the activator Na 2S of glycolate oxidase on glycolate oxidase activity, catalase activity, photorespiration rate and the contents of MDA, H 2O 2 and O -· 2 in wheat seedlings growing in 850 μmol m -2 s -1 light. The results showed that Na 2S increased glycolate oxidase activity and photorespiration rate (Figs.1,4), but decreased the contents of MDA and O -· 2 (Figs.2, 5). Oxalic acid decreased glycolate oxidase activity and photorespiration rate (Figs.1, 4), but increased the MDA and O -· 2 contents (Figs.2, 5). Oxalic acid and Na 2S had no effect on H 2O 2 content and catalase activity (Figs.3, 4). Oxalic acid and Na 2S also had no effect on H 2O 2 content and O -· 2 content in vitro reaction system (Figs.2,3). In addition, the activity of catalase was 1 000 times higher than that of glycolate oxidase in wheat seedlings (Fig.4). The result of statistical analysis showed that photorespiration rate negatively correlated with MDA content and O -· 2 content. These results suggest that the accumulation of O -· 2 and the increase in membrane lipid peroxidation level are inhibited by increasing photorespiration rate in wheat seedlings. But there is no correlation between photorespiration rate and H 2O 2 accumulation. Photorespiration can prevent the accumulation of active oxygen species and oxidative injury caused by it.

关 键 词： 活性氧 过氧化氢酶 乙醇酸氧化酶 膜脂过氧化 光呼吸 小麦

领　　域： [生物学]