Insecticide-induced hormesis in insects

杀虫剂引起的昆虫毒物兴奋作用

• 批准号: RGPIN-2015-04639
• 负责人: Cutler, Gerald
• 金额: $ 2.33万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613081
• 关键词: Insecticide; induced; hormesis; insects

Very low doses of insecticide can have stimulatory effects on insects. This biphasic toxicological phenomenon, whereby a chemical may be toxic at high doses but stimulatory at low doses is called ‘hormesis’. We previously showed that exposure of insects to mild doses of insecticide can greatly stimulate population growth and alter expression of genes involved in stress response and development. However, we still have a relatively poor understanding of the ecological and evolutionary significance of insecticide-induced hormesis for insects. The long-term goal of the research program is to understand the adaptive significance and potential practical applications of hormetic stress responses in insects. This will serve as a centerpiece for the following short-term objectives/questions: - Does insecticide-induced hormesis “prime” insects to better cope with additional stressors they may later experience, and does this persist across generations? - Does insecticide-induced hormesis lead to increased mutation rates and detoxifying enzymes that accelerate development of insecticide resistance? - Can exposure to low doses of pesticide, as seen with other stressors, stimulate reproduction or learning in bees? - Can exposure to low doses of insecticide stimulate reproduction in biocontrol agents (natural enemies) over multiple generations, without affecting overall fitness? Different insect-insecticide models will be used to test hypotheses in laboratory or greenhouse settings, measuring molecular, biochemical, individual, and population endpoints. All experiments will involve training of undergraduate and graduate students, or post-doctoral fellows. The proposed work is original and poised to have high impact internationally. Few studies have tested if mild stress primes organisms for more stress later in life, and we know of no experiments that have studied the problem over multiple generations. We also are not aware of experiments examining the link between hormesis and pesticide resistance, despite there being good reasons to suspect a linkage exists. This is significant given the likely role of hormesis in pest population resurgences and ecological backlash. Though many have studied how to apply hormesis in human health, little effort has explored this with other organisms. The proposed experiments with biocontrol agents are novel and could provide insight on how to improve production of natural enemies in commercial rearing facilities. Our experiments with bees are innovative and have the potential to have high impact for those involved in the pesticide-pollinator debate. Many pesticides are certainly toxic to pollinators, but the possibility of pesticide-induced hormetic responses in bees has been overlooked. If our predictions hold, our results could be a “toxicological awakening” for scientists, legislators, and citizens engaged in pollinator risk assessment.

极低剂量的杀虫剂可对昆虫产生刺激作用。这种双相毒理学现象，即一种化学物质在高剂量下可能有毒，但在低剂量下可能具有刺激性，被称为“激素效应”。我们先前表明，昆虫暴露于温和剂量的杀虫剂可以极大地刺激种群增长，并改变参与应激反应和发育的基因表达。然而，我们仍然有一个相对贫穷的理解的生态和进化的意义，昆虫的杀虫剂诱导的毒物兴奋效应。该研究计划的长期目标是了解昆虫激素应激反应的适应意义和潜在的实际应用。这将作为以下短期目标/问题的核心： - 昆虫的兴奋效应是否会使昆虫更好地科普它们以后可能经历的额外压力，这种情况是否会持续几代人？ - 杀虫剂诱导的兴奋效应是否会导致突变率和解毒酶的增加，从而加速杀虫剂抗性的发展？ - 暴露于低剂量的农药，如其他应激源，可以刺激蜜蜂的繁殖或学习吗？ - 暴露于低剂量的杀虫剂能否刺激生物控制剂（天敌）多代繁殖，而不影响整体健康？ 不同的昆虫杀虫剂模型将用于在实验室或温室环境中测试假设，测量分子，生物化学，个体和种群终点。所有的实验将涉及本科生和研究生，或博士后研究员的培训。 拟议的工作是原创的，并准备在国际上产生很大的影响。很少有研究测试过温和的压力是否会使生物体在以后的生活中承受更多的压力，我们也不知道有实验研究过多代人的问题。我们也不知道有实验研究毒物兴奋效应和杀虫剂抗性之间的联系，尽管有很好的理由怀疑存在联系。考虑到毒物兴奋效应在害虫种群复活和生态反弹中的可能作用，这一点意义重大。虽然许多人已经研究了如何将毒物兴奋效应应用于人类健康，但很少有人在其他生物体中探索这一点。所提出的生物防治剂实验是新颖的，可以提供关于如何提高商业饲养设施中天敌产量的见解。我们对蜜蜂的实验是创新的，有可能对那些参与杀虫剂-传粉者辩论的人产生重大影响。许多杀虫剂对传粉者确实有毒，但杀虫剂诱导蜜蜂兴奋反应的可能性却被忽视了。如果我们的预测成立，我们的研究结果可能会对从事传粉者风险评估的科学家，立法者和公民产生“毒理学觉醒”。