DISSERTATION RESEARCH: The role of toxin complementation in herbivore defense

论文研究：毒素补充在草食动物防御中的作用

• 批准号: 1011503
• 负责人: Michael Singer
• 金额: $ 1万
• 依托单位: Wesleyan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1011503&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; role; toxin; complementation

Herbivores with specialized diets can co-opt the defensive chemicals of their food-plants for their own defense. This research provides a first test of the hypothesis that grazing herbivores do the same, by regulating their intake of multiple plant chemicals to optimize defense against enemies. Alternatively, grazing among toxic plants might benefit herbivores by reducing the harmful effects of over-ingesting a single toxin associated with a particular food-plant species. These alternative hypotheses will be tested through three experiments involving a caterpillar already known to ingest one type of plant toxin as a defense against lethal parasites. First, the researcher will investigate how parasitism and the type of parasite affect the caterpillar's intake of two types of toxins (found in different food-plants). Second, she will compare caterpillar resistance against parasites when they have consumed the two toxins singly or in combination. To address toxin dilution, this experiment will also determine the effects of these diets on the survival and growth of unparasitized caterpillars. Finally, she will test whether the ratio of toxins eaten by unparasitized caterpillars confers deterrency against ubiquitous ant predators. Taken together, these results will identify how this herbivore benefits by grazing on toxic plants. This work will connect the science of pharmacology with animal behavior and ecology. Humans, domesticated grazing herbivores, and wild grazing herbivores face the common problem of obtaining a healthy diet from a chemically diverse array of plant foods. Using grazing caterpillars as a model, this research will test and develop scientific theory that can be applied to other species, including livestock and humans. In addition, understanding the reasons for host plant selection by herbivores will inform the management and conservation of biodiversity in grasslands, which are imperiled ecosystems and home to the caterpillars, plants, predators and parasites under study.

具有特殊饮食的食草动物可以利用食用植物中的防御化学物质来进行自身防御。这项研究首次验证了这一假设：食草动物也能通过调节多种植物化学物质的摄入量来优化对天敌的防御，从而发挥同样的作用。另外，在有毒植物中放牧可能会减少过度摄入与特定食用植物物种相关的单一毒素的有害影响，从而使食草动物受益。这些替代假设将通过三个实验进行测试，其中涉及一种已知会摄入一种植物毒素以防御致命寄生虫的毛毛虫。首先，研究人员将研究寄生性和寄生虫的类型如何影响毛毛虫摄入两种类型的毒素（在不同的食用植物中发现）。其次，她将比较毛毛虫在单独或混合消耗两种毒素时对寄生虫的抵抗力。为了解决毒素稀释问题，该实验还将确定这些饮食对未寄生毛毛虫的生存和生长的影响。最后，她将测试未被寄生的毛毛虫吃掉的毒素的比例是否能够对无处不在的蚂蚁捕食者产生威慑作用。总而言之，这些结果将确定这种食草动物如何通过吃有毒植物而受益。这项工作将药理学与动物行为和生态学联系起来。人类、驯化的食草动物和野生食草动物面临着从化学成分多样化的植物性食物中获得健康饮食的共同问题。这项研究将使用食草毛毛虫作为模型，测试和开发可应用于其他物种（包括牲畜和人类）的科学理论。此外，了解食草动物选择寄主植物的原因将为草原生物多样性的管理和保护提供信息，草原是受到威胁的生态系统，也是所研究的毛毛虫、植物、捕食者和寄生虫的家园。