截形叶螨对高温胁迫的生理响应及耐热性评价

The Physiological Responses and Heat Tolerance Evaluation of Tetranychus truncatus Ehara to High Temperature Stress

摘要:

本研究通过高温暴露试验研究了截形叶螨(Tetranychus truncatus Ehara)雌成螨对高温的耐受极限及其体内生化物质对高温的生理响应,为制定截形叶螨的精准防控策略提供理论支撑。试验设置了不同温度梯度(38℃、42℃、46℃和50℃)和时间梯度(2 h、4 h、6 h、12 h和24 h)对截形叶螨进行胁迫处理,测定了死亡率以及短时高温胁迫对叶螨体内海藻糖、糖原、葡萄糖、蛋白质、甘油三酯、丙二醇、山梨醇,丙二醛的含量的变化。试验结果表明,在50℃高温处理24 h后时截形叶螨死亡率达到98.89%；暴露时间为12 h时,半致死温度(LT₅₀)为47.78℃,半致死时间(Lt₅₀)随温度升高而缩短,42℃时Lt₅₀为 67.71 h,46℃的Lt₅₀ 为17.89 h,在50℃仅需6.71 h。微量法试剂盒测定结果表明,随着温度升高和胁迫时间延长,截形叶螨体内海藻糖、蛋白质和甘油三酯含量整体显著增加；糖原含量在38℃下呈现先下降后上升的趋势；葡萄糖在2 h胁迫下,含量随着温度的升高呈先上升后下降的趋势；丙二醛含量在38℃和42℃处理下显著升高,50高温处理6 h时显著降低；山梨醇含量在38℃和42℃处理下显著增加,但在46℃和50℃处理下与对照相比无显著变化。以上结果说明截形叶螨在高温胁迫下通过调控体内生化物质的变化,从而增强其耐热性,为全球气候变暖背景下防控截形叶螨提供了理论依据。

Abstract:

In this study, the tolerance limit of female adults of Tetranychus truncatus Ehara to high temperature and the physiological reaction of biochemical substances in the body to high temperature were studied by high temperature exposure test, which provided theoretical support for formulating accurate prevention and control strategies for T. truncatus. T. truncatus was stressed by different temperature gradients (38℃, 42℃, 46℃ and 50℃) and time gradients (2 h, 4 h, 6 h, 12 h and 24 h), and the mortality of T. truncatus and the changes of trehalose, glycogen, glucose, protein, triglyceride, propylene glycol, sorbitol and malondialdehyde under short-term high temperature stress were determined. The results showed that the mortality of T. truncatus was 98.89% after being treated at 50℃ for 24 hours. When the exposure time was 12 hours, the semi-lethal temperature (LT₅₀) was 47.78℃, and the semi-lethal time (Lt₅₀) decreased with the increase of temperature. Lt₅₀ was 67.71 hours at 42°C, 17.89 hours at 46°C, and only 6.71 hours at 50°C. The results of the microanalysis kit showed that the contents of trehalose, protein and triglyceride in T. truncatus significantly increased with the increase of temperature and stress time. The content of glycogen first decreased and then increased at 38℃. Under the stress of 2 h, with the increase of temperature, the glucose content first increased and then decreased. The content of malondialdehyde (MDA) increased significantly at 38℃ and 42℃, and decreased significantly at 50℃ for 6 hours. The content of sorbitol increased significantly at 38℃ and 42℃, but there was no significant change at 46℃ and 50℃ compared with the control. The above results showed that T. truncatus can enhance its heat resistance by adjusting the changes of biochemical substances in vivo under high temperature stress, which provides a theoretical basis for the prevention and control of T. truncatus under the background of global warming.