Insect bacterial symbionts and short term adaptation of aphids to abiotic and biotic stress

昆虫细菌共生体和蚜虫对非生物和生物胁迫的短期适应

• 批准号: RGPIN-2014-06366
• 负责人: Cloutier, Conrad
• 金额: $ 1.75万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647838
• 关键词: Insect; bacterial; symbionts; short; term

Modern theories of evolution consider microbial symbionts of animals and plants as key mediators helping their host to adapt to rapid ecological change in their resources, natural enemies, and climatic conditions. We will use small insects called aphids and their parasitic wasps in controlled experiments, to test the hypothesis that aphids critically depend on the rapid evolutionary potential of their bacterial symbionts to survive to ecological stress that they face as part of their daily life on vascular plants used as their food and habitat. A well known species, the pea aphid, will be exposed to experimental evolution in distinct regimes of ecological stress imposed on them either as more or less virulent parasites, shifts between differently hospitable host plant species, or as a high temperature stress which they often face daily in hot summer while feeding on aerial plant parts. Four species of aphid bacterial symbionts among the best known to be maternally inherited in these aphids will be monitored closely using molecular techniques during the course of successive generations of stress, to document adaptive changes in the aphid bacterial community under particular stress regimes. Our findings should help to understand if aphids under stress respond quickly and adaptively to specific ecological threats, by modulating the size and composition of their bacteriome, which can be expected because of the fast rate of multiplication of bacteria compared to insects. Our study system is unique in bringing under scrutiny four levels of a natural terrestrial food web, where we will experiment with plants, small insect herbivores, their consortia of symbiotic bacteria, and parasitic wasps attacking them as natural enemies.

现代进化理论认为，动植物的微生物共生体是帮助宿主适应资源、天敌和气候条件快速生态变化的关键媒介。我们将在受控实验中使用称为蚜虫的小型昆虫及其寄生蜂，以验证蚜虫严重依赖其细菌共生体的快速进化潜力以生存于生态压力的假设，这些生态压力是他们日常生活的一部分，这些生活是以维管植物作为食物和栖息地。一个众所周知的物种，豌豆蚜虫，将暴露于实验进化的不同制度的生态压力强加给他们或多或少的有毒寄生虫，不同的好客的寄主植物物种之间的转变，或作为高温胁迫，他们经常面临每天在炎热的夏天，而在空中植物部分喂养。四个物种的蚜虫细菌共生体中最有名的是母系遗传在这些蚜虫将密切监测，在连续几代的压力过程中使用分子技术，记录适应性变化的蚜虫细菌群落在特定的压力制度。我们的研究结果应该有助于了解压力下的蚜虫是否能通过调节其细菌组的大小和组成来快速适应特定的生态威胁，这是可以预期的，因为与昆虫相比，细菌的繁殖速度很快。我们的研究系统是独一无二的，它将对自然陆地食物网的四个层次进行详细审查，在那里我们将对植物，小型昆虫食草动物，共生细菌财团以及寄生蜂进行实验，攻击它们作为天敌。