添加外源锌对大杯香菇子实体细胞保护酶活性的影响

摘要：【目的】本实验研究了添加外源锌（Zn）对大杯香菇子实体保护酶活性的影响。【方法】以硫酸锌为外源锌，添加到培养料中，制成0、10、20、30、40、50 mg/kg 6个浓度。采用分光光度法测定大杯香菇子实体超氧化物岐化酶（SOD）活性、过氧化物酶（POD）活性、多酚氧化酶（PPO）活性、丙二醛（MDA）含量和可溶性蛋白含量，采用高锰酸钾滴定法过氧化氢酶（CAT）活性。【结果】添加外源 Zn浓度为30 mg/kg处理大杯香菇子实体内可溶性蛋白含量、SOD、POD和CAT活性极显著提高（P＜0.01），PPO活性极显著减少（P＜0.01），而MDA含量显著下降（P＜0.05）。随着Zn水平进一步升高，可溶性蛋白含量、SOD、POD和CAT活性呈下降趋势，而MDA含量极显著和显著上升（P＜0.01和P＜0.05）。【结论】高用量的Zn浓度能使大杯香菇子实体中的MDA含量上升，SOD、POD、CAT活性均下降，对保护酶系统有破坏作用，促进自由基的积累，从而导致膜脂过氧化作用的加剧。适宜Zn浓度能提高保护酶的活性，从而抑制了大杯香菇子实体中细胞膜脂过氧化水平，减轻膜伤害。

Effect of exogenous zinc addition on cell protective enzyme activities in the fruit bodies of Lentinus giganteus

Abstract: Objective] The effects of exogenous Zn addition on cell protective enzyme activities in the fruit bodies of Lentinus giganteus were studied. Methods] ZnSO4 was used as exogenous Zn and added into culture medium. The final Zn concentrations in culture media were 0, 10, 20, 30, 40, 50 mg/kg respectively. The activities of superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO), malondialchehyche (MDA) content and soluble protein content in the fruit bodies were analyzed by spectrophotometry; catalase (CAT) was determined by potassium permanganate titration. Results] The content of soluble protein and SOD, POD and CAT activities in the fruit bodies of L. giganteus were significantly increased (P<0.01), but PPO activity (P<0.01) and MDA content (P<0.05) was significantly decreased in the treatment of 30 mg/kg Zn concentration. The content of soluble protein and SOD, POD and CAT activities showed a decreasing trend with the increase of Zn concentration, but MDA content was significantly increased (P<0.01 and P<0.05 ). Conclusion] High Zn concentration caused the increase of MDA contents and the decrease of SOD, POD and CAT activities in the fruit body of L.giganteus. It will destroy the protective enzyme system, cause the accumulation of free radicals and thus intensify membrane lipid peroxidation. Appropriate Zn concentration improved the protective enzyme activities, and lightened the harm of membrane from lipid peroxidation.