DISSERTATION RESEARCH: Plant toxicity at the top of a tropical mountain

植物与其专业食草动物之间的“化学军备竞赛”的特征是植物防御和食草昆虫对这些防御的适应性的高度差异，并且被认为是生物多样性的驱动力。在热带胡椒植物中新发现的植物毒素，Piper kelleyi，被专门吃这种植物的毛虫消耗和代谢。 这些化学物质对所有其他昆虫都是有毒的，特别是在光照较强的环境中。该研究将定量测量植物毒素的丰度和多样性如何对不同的光照强度做出反应，并将记录专业毛毛虫如何应对植物化学差异。该研究战略将遗传学和有机化学的最新进展与植物-昆虫相互作用的重要生态问题联系起来。该项目将加强研究生教育，并将通过与当地K-12学生，教师和国际合作者的互动项目促进科学教育。除了提供深入了解生物多样性的起源，记录在植物化学相互作用的营养水平的变化的影响提供了数据，可能是有用的药理学和agricultural.The论文研究将提供植物次生代谢产物如何有助于起源和维持热带地区的生物多样性的研究作出重大贡献。这项工作探讨了具体的假设相关的共同进化理论，利用最近发现的植物次生代谢产物的热带林下灌木，胡椒（科）。这些化合物在较高的光照水平下二聚并且毒性更大，被Eois属中的专业尺蠖毛虫消耗和代谢，但它们对通才非常有毒。使用该模型系统测试的假设包括：1）如果在不同的宿主植物种群中发现不同的植物化学谱，这些可以作为食草动物的隔离机制，以及2）这些隔离机制导致专门食草动物的物种形成。光强度将被操纵，以量化其对种内植物化学变化的影响，和人口基因组学技术将提供测试这些化合物的解毒专家毛虫当地适应。该项目还将为研究生提供机会，他们将通过与当地K-12学生，教师以及化学家和生物学家的国际团队的互动项目促进科学教育。

The "chemical arms race" between plants and their specialist herbivores is characterized by high diversities of both plant defenses and insect herbivores with adaptations to those defenses, and is considered to be a driving force of biodiversity. The newly discovered plant toxins in the tropical pepper plant, Piper kelleyi, are consumed and metabolized by caterpillars that specialize on this plant. These chemicals are toxic to all other insects, especially in higher light environments. The research will quantitatively measure how the abundance and diversity of plant toxins respond to different light intensities and will document how specialized caterpillars evolve in response to differences in plant chemistry. The research strategy links the most recent advances in genetics and organic chemistry with important ecological questions about plant-insect interactions. The project will enhance graduate education and will promote science education through interactive projects with local K-12 students, teachers, and an international group of collaborators. In addition to providing insight into the origins of biodiversity, documenting the effects of variation in plant chemistry on interacting trophic levels provides data that could be useful for pharmacology and agriculture.The dissertation research will provide a significant contribution to studies of how plant secondary metabolites contribute to the origin and maintenance of biodiversity in the tropics. The work examines specific hypotheses relevant to coevolutionary theory using the recently discovered plant secondary metabolites of the tropical understory shrub, Piper kelleyi (Piperaceae). These compounds, which dimerize and are more toxic at higher light levels, are consumed and metabolized by specialist geometrid caterpillars in the genus Eois but they are very toxic to generalists. The hypotheses tested using this model system include: 1) if distinct phytochemical profiles are found in different host plant populations, these can function as isolating mechanisms for herbivores, and 2) these isolating mechanisms lead to speciation of specialist herbivores. Light intensities will be manipulated to quantify their effects on intraspecific phytochemical variation, and population genomics techniques will provide tests for local adaptation of detoxification of these compounds by specialist caterpillars. The project will also provide opportunities for the graduate student, who will promote science education through interactive projects with local K-12 students, teachers, and an international team of chemists and biologists.