低温胁迫对柞蚕幼虫3种抗氧化酶活性的影响

Effect of Low Temperature Stress on Activity of Three Antioxidases in Antheraea pernyi Larvae

低温环境是影响柞蚕茧产量,制约柞蚕产业提质增效的主要因素之一。本试验通过研究低温胁迫后柞蚕幼虫体内SOD、CAT和POD 3种抗氧化物酶的活性,比较4个柞蚕品种/品系的抗逆能力,探索低温胁迫后柞蚕的抗逆机制。5℃低温胁迫4个柞蚕品种/品系的5龄幼虫24 h,在低温胁迫后0、24、48 h测定低温处理组与同时期对照组幼虫血淋巴中3种抗氧化物酶的活性。结果显示,3种抗氧化酶3个时间点的平均值分析,同品种/品系低温处理组与对照组间,辽蚕527和抗大的平均SOD活性呈显著差异;辽蚕527和9906的平均CAT活性呈显著差异;辽蚕527、辽蚕582及9906的平均POD活性均呈显著差异。而不同品种/品系低温处理组间平均SOD活性显示辽蚕527、抗大与9906,抗大与辽蚕582均存在显著差异;平均CAT活性在品种/品系间无显著差异;平均POD活性显示辽蚕527与辽蚕582、抗大,9906与抗大具有显著差异。4个品种/品系的SOD、CAT活性在低温胁迫后表现出先上升后下降的趋势,在24 h达到最高;而POD活性为上升趋势。综合评价4个柞蚕品种/品系3种抗氧化酶在低温胁迫后的酶活性,以辽蚕527最好。研究结果可为柞蚕抗逆性机理研究与抗性品种选育提供理论依据。

Low temperature is one of the main factors that affect cocoon yield of Antheraea pernyi, and improvement of quality and efficiency in A. pernyi industry. In this study, activity of 3 kinds of antioxidases including SOD, CAT and POD in A. pernyi were studied to compare stress resistance of 4 A. pernyi varieties/strains, and to explore resistance mechanism of A. pernyi in response to low temperature stress. The 5 th instar larvae of 4 A. pernyi varieties/strains were treated at 5 ℃ for 24 h, and then activity of 3 antioxidases in hemolymph from low temperature treatment groups and control group was measured at 0, 24, 48 h after low temperature treatment. Analysis on mean values of 3 antioxidase activity at 3 time points showed that mean values of SOD activity between Liaocan 527 and Kangda, mean values of CAT activity between Liaocan 527 and 9906, and mean values of POD activity between Liaocan 527, Liaocan 582 and 9906 were significantly different in low temperature treatment groups and control group of the same variety/strain. In contrast, mean values of SOD activity in low temperature treatment groups of different varieties/strains were significantly different not only between Liaocan 527, Kangda and 9906, but also between Kangda and Liaocan 582. Furthermore, there was no significant difference in mean values of CAT activity between different varieties/strains. Mean values of POD activity were significantly different between Liaocan 527 and Liaocan 582, between Liaocan 527 and Kangda, and between 9906 and Kangda. SOD and CAT activity of 4 varieties/strains showed an increase and then a decrease under low temperature stress, reaching to the highest at 24 h, while POD activity consistently increased. According to comprehensive evaluation on activity of 3 antioxidases in 4 tussah varieties/strains under low temperature stress, Liao 527 was the best. The results can provide theoretical basis for the study on stress resistance mechanism and breeding of resistant varieties.