高温胁迫对双斑长跗萤叶甲成虫总蛋白和两种保护酶的影响

Effects of high temperature stress on total protein and two protective enzymes in adult Monolepta hieroglyphica(Motschulsky)

双斑长跗萤叶甲是新疆北疆棉花的主要害虫之一。本研究旨在探索短时高温对双斑长跗萤叶甲成虫生理生化的影响。在室内研究了不同高温(33℃、37℃、41℃、45℃)不同时间(0.5 h、1.5 h、2.5 h、6 h、12 h)处理后,双斑长跗萤叶甲成虫体内总蛋白含量、过氧化物酶(POD)及过氧氢酶(CAT)的变化规律。双斑长跗萤叶甲成虫总蛋白在37℃处理12 h时,蛋白含量最高,41℃处理12 h时有所下降,45℃时双斑长跗萤叶甲只能存活1.5 h,但蛋白含量仍高于对照(26℃)。POD活性随温度升高先升高后降低。在33℃处理6 h时,活性最高,在41℃处理12 h时,活性最低。CAT活性在同一时间不同温度处理中呈先降后升再降趋势。在37℃处理1.5 h时活性达到最高,在41℃处理12 h时活性最低。在同一温度不同处理时间中,CAT活性在33℃时先升高后降低,在37℃、41℃时随时间的延长先升高后降低,在45℃时持续降低,且显著低于对照(26℃)。双斑长跗萤叶甲总蛋白及保护酶的活性与温度密切相关,据此推测高温下双斑长跗萤叶甲成虫死亡的原因与保护酶系统被破坏有关。

Monolepta hieroglyphica（Motschulsky） is one of the most serious pests of cotton fields in the north of Xinjiang Uyghur Autonomous Region. This study aims to explore the potential physiological and biochemical effects of adult M. hieroglyphica exposed to high temperature. The contents of total protein,POD and CAT variation in adult bodies were measured after these leaf beetles had been placed in climate cabinet under consistent temperature regimes of 33℃-45℃ at 4℃ intervals for 0. 5 h,1. 5 h,2. 5 h,6 h,12 h,respectively. The highest total protein contents of adult M. hieroglyphica was at the treatment of 37℃ for 12 h,and decreased at the treatment of 41℃ for 12 h. Although the leaf beetle only lived for 1.5 h at 45℃,the protein content still increased compared to control（26℃）. POD activity of adultM. hieroglyphica were increased and then decreased with the rises of temperature,and were at the highest in the treatment of 33℃ for 6 h,while at the lowest in the treatment of 41℃ for 12 h. CAT activity of adult M. hieroglyphica were decreased first and then increased, and decreased again at different temperature level with the same time treatment. CAT activity were at the highest in the treatment of 37℃ for 1. 5 h,and at the lowest in the treatment of 41℃ for 12 h. At the same temperature and different treatment time,the activity of CAT was increased at first and then decreased at 33℃. At 37℃ and 41℃,CAT activity were increased and then decreased with the extending of the time. At 45℃,CAT activity were gradually decreased with the time and was significantly lower than the control（26℃）. The results showed that protein and the activities of the two protective enzymes of M. hieroglyphica were closely related to temperature. We speculated that the death of M. hieroglyphica were caused damaged protective enzyme system under the high temperature stress.