环境对蝗虫微孢子虫孢子能量代谢和应激反应的影响

Effects of environment conditions on spore energy metabolism and stress responses of Paranosema locustae

摘要:

蝗虫微孢子虫(Paranosema locustae)作为一种环境友好的生物防治剂，在蝗虫生物防治中具有广阔的应用潜力。然而，在实际应用中，其效果会受到多种环境因素的影响。因此了解蝗虫微孢子虫对不同环境的抗性差异，对其在生物防治中的应用至关重要。目的 探究不同环境条件对蝗虫微孢子虫能量代谢和应激反应，为蝗虫微孢子虫的环境适应性提供理论基础。方法 将蝗虫微孢子虫孢子制剂暴露于3种可控的实验环境中，分别是40 °C干燥环境、20 °C水环境以及干燥条件下紫外线(≥100 μW/cm2)辐照不同时间。通过酶标仪、激光共聚焦显微镜和相差显微镜，分别测定处理后的蝗虫微孢子虫感染蝗虫的生存曲线、孢子发芽率、ATP含量、蛋白量、活性氧(active oxygen, ROS)水平以及海藻糖含量。结果 在20 °C水环境中处理后，蝗虫微孢子虫的发芽率降低，感染蝗虫的中位生存时间延长；同时，其ATP和ROS水平显著上升。在40 °C干燥环境下，孢子的ATP浓度和ROS水平无显著变化，发芽率以及感染蝗虫的生存曲线与对照组相比也无显著差异。此外，在高强度紫外线照射(≥100 μW/cm2)下，蝗虫微孢子虫的ATP浓度也显著上升，ROS反应增强，但发芽率以及感染蝗虫的生存曲线未出现显著变化。结论 干燥状态的蝗虫微孢子虫对环境具有更强的抗性，而长时间处于液体环境中会导致孢子活力降低甚至丧失。这些结果为蝗虫微孢子虫生物治蝗制剂的保存方法和应用提供了思路，并为其环境适应性研究提供了理论基础。

Abstract:

Paranosema locustae, an environmentally friendly biocontrol agent, holds significant potential for managing locusts. However, its application is affected by various environmental factors. Understanding the resistance differences of P. locustae under different conditions is essential for its application in biocontrol.Objective To study the effects of different environmental conditions on the energy metabolism and stress responses of P. locustae, providing a theoretical foundation for its environmental adaptability.Methods Spores of P. locustae were exposed to three controlled experimental environments: a dry environment at 40 °C (40 °C GR), a wet environment at 20 °C (20 °C SR), and ultraviolet irradiation under dry conditions (≥100 μW/cm²) (ZW) for varying time periods. We employed a microplate reader, laser confocal microscopy, and differential interference contrast microscopy to assess the survival curves of infected locusts and the spore germination rate, ATP level, protein content, reactive oxygen species (ROS) level, and trehalose level of P. locustae.Results In the 20 °C SR group, P. locustae showed a decrease in the germination rate and notable rises in ATP and active oxygen (ROS) levels, and the median survival time of infected locusts increased. The 40 °C GR group showed no significant changes in the ATP level, ROS level, spore germination rate, or the survival curve of infected locusts compared with the control group. The ZW group showed increases in the ATP and ROS levels, but no significant change in the germination rate or the survival curve of infected locusts.Conclusions Dry spores of P. locustae exhibit greater resistance to environmental stress, while prolonged exposure to liquid conditions leads to a decrease or even loss of spore viability. These findings provide insights for the preservation and application of P. locustae formulations, establishing a theoretical basis for revealing its environmental adaptability.