葱蝇非滞育、夏滞育和冬滞育蛹体内抗氧化酶活性的比较分析

摘要

[Aim]In order to investigate the differences of antioxidant system in non-diapause (ND),summer diapause (SD) and winter diapause (WD) pupae of Delia antiqua,the variations of antioxidant enzyme activities and glutathione redox status were determined and compared. [Methods]Time-course variations of antioxidant enzyme activities of copper /zinc-SOD (Cu /Zn-SOD),manganese superoxide dismutase (MnSOD), catalase (CAT),glutathione peroxidase (GPx) and glutathione reductase (GR),and contents of reduced glutathione (GSH) and oxidized glutathione (GSSG) and their ratio were measured and compared between different stages of ND,SD and WD pupae of D. antiqua. Canonical discriminate analysis was also conducted to further explore the relationships between the major antioxidant components. [Results]The activities of all the five antioxidant enzymes dynamically changed during the whole pupal stage. Compared with ND and SD pupae, WD pupae at the pre-diapause phase had higher Cu /Zn-SOD activities. The mean Cu /Zn-SOD activity in SD or WD pupae at the diapause maintenance phase and post-diapause phase was much lower than that in ND pupae. In the whole pupal stage,ND pupae had higher MnSOD activities than SD and WD pupae,but no difference existed between SD and WD pupae. The average MnSOD activity was distinctly higher than that of Cu /Zn-SOD at the same developmental stage. The CAT activities in SD and WD pupae at the pre-diapause phase were statistically higher than that in ND pupae at the same developmental stage,however,the CAT activities in SD or WD pupae at the diapause maintenance phase and post-diapause phase were significantly lower than those in ND pupae. In either non-diapause or diapause pupae at the same developmental stage,the general GPx activities showed an opposite variation trend with GR activities. Canonical discriminant analysis revealed that antioxidant system in onion fly pupae showed diapause type specificity. [Conclusion]Redox status in ND pupae is significantly different from that in SD and WD pupae. Higher antioxidant enzyme activities and lower GSH/GSSG ratio in pupae at the pre-diapause phase and post-diapause phase suggest that the oxidative shift results from a higher respiration rate and development changes.%[目的]通过测定并比较分析抗氧化酶活性及谷胱甘肽氧化还原状态,探讨葱蝇Delia antiqua 非滞育、夏滞育和冬滞育蛹体内抗氧化系统的差异.[方法]取葱蝇非滞育、夏滞育和冬滞育蛹,分别测定铜锌超氧化物歧化酶(Cu /Zn-SOD) 、锰超氧化物歧化酶(MnSOD) 、过氧化氢酶(CAT) 、谷胱甘肽过氧化物酶(GPx) 和谷胱甘肽还原酶(GR) 活性及还原型谷胱甘肽(GSH) 和氧化性还原型谷胱甘肽(GSSG) 含量及GSH/GSSG 比随发育时间的变化; 并对各抗氧化因子进行了典型判别分析.[结果]5 种抗氧化酶的活性在整个蛹期是动态变化的.与非滞育蛹和夏滞育蛹相比,处于滞育前期的冬滞育蛹具有较高的Cu /Zn-SOD 酶活性,但处于夏滞育及冬滞育的维持期和滞育后期的滞育蛹体内Cu /Zn-SOD 酶活性则明显低于同一发育时期的非滞育蛹.在整个蛹期,非滞育蛹体内MnSOD 酶活性显著高于夏滞育和冬滞育蛹,而在夏滞育和冬滞育蛹之间则无明显差异.比较两种酶活性则发现同一发育时期的MnSOD 平均酶活性明显高于Cu /Zn-SOD 酶活性.在头外翻之前,滞育蛹体内CAT 酶活性高于非滞育蛹,但处于滞育维持期和后期的蛹体内CAT 酶活性则低于非滞育蛹.无论在非滞育蛹还是滞育蛹中,GPx 和GR 酶活性变化基本上呈相反的趋势.典型判别分析进一步表明葱蝇蛹体内的抗氧化系统具有发育时期和滞育类型特异性.[结论]非滞育蛹与夏滞育和冬滞育蛹体内的氧化还原状态存在明显差异.滞育前期和滞育后期的蛹体内较高的抗氧化酶活性和较低的GSH/GSSG 比提示氧化状态的变化与高的呼吸速率及发育过程密切相关.