【摘要】 以酸枣水培幼苗为试材,研究不同浓度NaCl处理下酸枣幼苗根、茎和叶中还原型抗坏血酸（AsA）、氧化型抗坏血酸（DHA）、还原型谷胱甘肽（GSH）、氧化型谷胱甘肽（GSSG）含量和抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR）、脱氢抗坏血酸还原酶（DHAR）以及单脱氢抗坏血酸还原酶（MDHAR）活性的变化。试验数据表明,与对照相比,随着NaCl处理浓度的升高,酸枣幼苗根、茎和叶中AsA含量均增加;DHA含量也呈上升趋势;叶片中AsA/DHA比值呈先上升后下降的趋势;叶中GSH含量变化呈现先升高后下降的趋势;200 mmol?L^-1 NaCl处理下茎中GSSG含量显著升高;茎中GSH/GSSG比值呈先升高后下降的趋势;酸枣幼苗各器官中APX活性随着NaCl浓度的升高逐渐下降;GR活性、MDHAR活性与对照相比存在显著差异。总之,高浓度的NaCl胁迫下,酸枣幼苗根、茎和叶中AsA、DHA含量增加,APX活性下降;茎和叶中GSSG含量增加。NaCl胁迫下,酸枣幼苗AsA-GSH循环中催化AsA再生的主要酶可能是MDHAR。更多还原

【Abstract】 A hydroponic experiment was conducted to study the effects of NaCl concentration on the ascorbate-glutathione（AsA-GSH） cycle in roots,stems and leaves of sour jujube.The results showed the NaCl treatments significantly increased AsA（absocrbic acid） and dehydroascorbic acid（DHA） concentrations in jujube roots,stems,and leaves.The As A/DHA ratio and the reduced glutathione（GSH） concentration in leaves increased and then decreased as NaCl stress increased.The 200 mmol?L^-1 NaCl treatment significantly increased oxidized glutathione（GSSG） concentrations in jujube leaves.The GSH/GSSG ratio in stems increased and then decreased as Na Cl stress increased.The NaCl treatments significantly reduced ascorbate peroxidase（APX activity） in jujube roots,stems,and leaves.In contrast,Na Cl had significant effect on the activity of either glutathione reductase（GR） or monodehydroascorbate reductase（MDHAR）.In conclusion,high Na Cl concentrations increased As A and DHA concentrations but reduced APX activity in roots,stems and leaves of sour jujube.The NaCl also increased GSSG concentrations in stems and leaves.In the AsA-GSH cycle in sour jujube,MDHAR is the main enzyme that regenerates AsA from DHA.更多还原