污灌与镉胁迫对菠菜几种抗氧化酶活性的影响（Effects of Sewage Irrigation and Cadmium Stresses on the Activities of Several Antioxidant Enzymes of Spinach）

为了探讨污水灌溉与镉胁迫对菠菜抗氧化酶活性的影响,采用盆栽试验的方法,分别用清水和生活污水配制不同浓度(0、1、5、10、50mg·L-1)的Cd2+溶液,对菠菜进行受试处理,每5d灌喷1次,共处理5次.分别采用邻苯二酚比色法、L-苯丙氨酸比色法、水杨酸比色法和高锰酸钾滴定法,对菠菜叶片多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、β-1,3葡聚糖酶(β-1,3glucanase)和过氧化氢酶(CAT)活性进行了测定.结果表明:1)清水处理系列:随着镉处理浓度的增大,与清水对照相比,PPO、PAL活性呈先升高后降低的趋势,CAT活性略有升高,β-1,3葡聚糖酶活性略有降低,各暴露组与清水对照组相比,均呈现显著差异(p<0.05).2)污水处理系列:随着镉处理浓度的增大,与污水对照相比,PPO、PAL活性呈先升高后降低的趋势,CAT和β-1,3葡聚糖酶活性呈逐渐降低趋势;各暴露组与污水对照相比,均呈现显著差异(p<0.05).3)相同Cd2+浓度下,与清水处理相比,各浓度污水处理PAL和PPO活性均明显降低(p<0.05);而β-1,3葡聚糖酶明显升高(p<0.05).以上结果显示:单一镉污染和生活污水与镉复合污染对菠菜不同抗氧化系统酶具有不同影响,这可能与污水中各成分与镉的相互作用有关.

Effects of Sewage Irrigation and Cadmium Stresses on the Activities of Several Antioxidant Enzymes of Spinach

To explore the effects of sewage irrigation and cadmium stresses on the activities of several antioxidant enzymes of spinach,spinach was exposed to sewage and clean water irrigation in different concentrations of cadmium(0,1,5,10,50mg·L-1)by pot experiment.PAL,PPO,β-1,3 glucanase and CAT activities of spinach leaves were measured by Catechol assay,L-phenylalanine assay,Salicy acid assay and potassium permanganate titration.Results showed that 1) The clean water treatment series:compared with the water control group,with the increasing of Cd2+ concentrations,PPO and PAL activities of spinach increased at the beginning and then decreased afterwards,CAT activity of spinach slightly increased,β-1,3 glucanase activity of spinach gradually decreased,and the significant difference was observed in the treatment groups(p<0.05);2)The sewage treatment series:compared with the sewage control group,with the increasing of Cd2+ concentrations,PPO and PAL activities of spinach increased at the beginning and then decreased afterwards,CAT and β-1,3 glucanase activities of spinach gradually decreased,and there was significant difference between treatment groups and control groups(p<0.05);3)Compared with the control groups,PAL and PPO activities by sewage treatments significantly decreased(p<0.05)in the same concentration of Cd2+,while β-1,3 glucanase activity significantly increased(p< 0.05).Above results indicated that single pollution of Cd and combined pollution of sewage and Cd had different effects on the various antioxidant enzymes of spinach,which was relating to the interaction between Cd and composition in sewage.