Abstract: In order to explore the effects of alkaline salt stress on the ascorbic acid-glutathione cycle（AsA-GSH） of mitochondria in the radicle and plumule of Bothriochloa ischaemum， this experiment used ‘Taihang’ Bothriochloa ischaemum as material， which was germinated in NaHCO₃ and Na₂CO₃ solutions with Na⁺ concentration of 0（CK）， 10 and 30 mmol·L^-1， and then changes in the activities of AsA-GSH enzymes and lipid peroxidation in their mitochondria of radicle and plumule were analyzed. The results showed that the activities of superoxide dismutase， catalase， glutathione peroxidase and monodehydroascorbate reductase in the mitochondria of radicle increased with the increase of Na⁺ concentration （0-30 mmol·L^-1）， but the opposite phenomenon was observed in the activities of glutathione sulfur transferase， ascorbate peroxidase and glutathione reductase. With the increase of Na⁺ concentration （0-30 mmol·L^-1）， the activities of superoxide dismutase， catalase and glutathione peroxidase in the mitochondria of plumule increased significantly （P<0.05）， but the activities of glutathione sulfur transferase， glutathione reductase and monodehydroascorbate reductase decreased significantly （P<0.05）. There were differences in the effects of type and concentration under alkaline salt on the AsA-GSH in radicle and plumule of Bothriochloa ischaemum， and the sensitivity of mitochondrial AsA-GSH in radicle of Bothriochloa ischaemum to alkaline salt stress was higher than that in plumule.

Key words: Alkaline salt stress, Bothriochloa ischaemum, Mitochondria, Ascorbic acid-glutathione cycle, Radicle, Plumule

摘要： 为探究碱性盐胁迫对白羊草（Bothriochloa ischaemum）胚根和胚芽线粒体抗坏血酸-谷胱甘肽（AsA-GSH）循环的影响，本试验以‘太行’白羊草为材料，在Na⁺浓度为0（CK），10和30 mmol·L^-1的NaHCO₃和Na₂CO₃溶液中进行萌发试验，分析其胚根和胚芽线粒体AsA-GSH循环酶活性及脂质过氧化变化规律。结果表明：白羊草胚根线粒体中超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和单脱氢抗坏血酸还原酶活性随Na⁺浓度（0~30 mmol·L^-1）的增加均呈上升趋势，而其谷胱甘肽硫转移酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性则相反；白羊草胚芽线粒体中超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶活性随Na⁺浓度（0~30 mmol·L^-1）的增加均显著上升（P<0.05），而其谷胱甘肽硫转移酶、谷胱甘肽还原酶和单脱氢抗坏血酸还原酶活性则显著下降（P<0.05）。碱性盐种类和浓度对白羊草胚根和胚芽AsA-GSH循环的影响存在差异，且胚根线粒体AsA-GSH循环响应碱性盐胁迫的敏感性要高于胚芽。

关键词: 碱性盐胁迫, 白羊草, 线粒体, 抗坏血酸-谷胱甘肽循环, 胚根, 胚芽