不同叶龄菠菜叶片抗坏血酸含量与其代谢相关酶活性的比较

Comparison of Ascorbic Acid Content and Activities of Metabolism Relative Enzymes in Various Ages of Spinach Leaves

以欧丽特菠菜叶片为试材,研究了菠菜叶片发育过程中3个时期叶片(幼叶、成熟叶、衰老叶)的抗坏血酸代谢变化及抗坏血酸含量与其相关酶活性的关系。结果表明:抗坏血酸(AsA)和氧化型抗坏血酸(DHA)含量的变化趋势与L-半乳糖-1,4-内酯脱氢酶(GalLDH)以及脱氢抗坏血酸还原酶(DHAR)活性的变化趋势基本一致,而与抗坏血酸过氧化物酶(APX)活性变化呈此消彼长。同时单脱氢抗坏血酸还原酶(MDHAR)、谷胱甘肽还原酶(GR)和还原型谷胱甘肽(GSH)有助于AsA的再生。说明通过增加GalLDH和再生酶活性能提高菠菜叶片AsA的含量,并延缓其衰老。

The ascorbic acid （AsA） metabolism, AsA content, activities of relative enzymes and rela- tionship between them were studied in leaves of spinach cultivar Olet at various ages, i.e. young leaves, ma- ture leaves, aged leaves. The results showed that the content changes of AsA and oxidized ascorbic acid （DHA） were accordant with the activity changes of GalLDH and DHAR, but shifted with the change of APX activities. MDHAR, GR and GSH conduced to the regeneration of AsA. These results demonstrated that the activities of GalLDH and regenerative enzymes could increase the AsA content in spinach leaves and delay its senescence.