DISSERTATION RESEARCH: Ecological Costs and Benefits of Secondary Compounds in Fleshy Fruits

因为植物是扎根的，它们在新地区定居的能力通常依赖于动物，动物吃水果，搬到其他地方，然后把这些水果中包含的种子储存起来。这种形式的种子传播对于森林的自然更新是必不可少的。为了吸引种子传播者，植物生产出营养丰富的五颜六色的水果；然而，这些水果中的营养物质也会吸引水果害虫，如导致水果腐烂的昆虫和真菌。作为对这种敌人的防御，植物会产生一系列被称为天然产物或次生化合物的化合物，这些化合物可以用作杀虫剂或杀菌剂。这些化合物经常被人类用作有机杀虫剂或用于治疗感染，但人们对水果中产生的化合物的种类以及它们如何影响以水果为食物的动物知之甚少。这项研究将研究在热带胡椒植物(胡椒科)中发现的一组这种水果天然产物--酰胺-生物碱，这一大类包括几个重要的经济物种(如黑胡椒，其果实是黑胡椒的来源)。一系列实验将测试单独的酰胺-生物碱对热带森林中食用辣椒水果的生物体的影响。这些生物包括食果蝙蝠，它们是辣椒果实的主要有益种子传播者，以及昆虫和真菌等水果害虫。所有田间实验将在哥斯达黎加的La Selva生物站进行，该地区发现了大量的辣椒植物及其相关的水果蝙蝠、害虫和真菌。这项研究的好处包括提高对种子传播和水果对害虫的自然防御的了解--这两个过程对植物生存至关重要，与农业和森林管理直接相关。此外，这项研究将为本科生和研究生的培养创造极好的机会，因为它结合了生物和化学。研究团队将包括来自美国和哥斯达黎加的学生，为国际合作和文化交流提供机会。结果将通过科学出版物以及针对K-12学生和普通公众的教育活动传播。

Because plants are rooted in place, their ability to colonize new areas often depends on animals, who consume fruits, move elsewhere, and then deposit the seeds contained in those fruits. This form of seed dispersal is essential for the natural regeneration of forests. To attract seed dispersers, plants produce nutritious and colorful fruits; however, the nutrients in those fruits can also attract fruit pests, such as insects and fungi that cause fruits to rot. As a defense against such enemies, plants produce an array of chemical compounds, called natural products or secondary compounds, that can act as insecticides or fungicides. These compounds are often used by humans as organic pesticides or in the treatment of infections, but very little is known about the variety of compounds produced in fruits and how they affect the animals that depend on fruits for food. This research will examine a group of these fruit natural products, the amide-alkaloids, that are found in tropical pepper plants (family Piperaceae), a large group that includes several economically important species (such as Piper nigrum, the fruits of which are the source of black pepper). A series of experiments will test the effects of individual amide-alkaloids on the organisms that consume pepper fruits in tropical forests. These organisms include fruit-feeding bats, which are the main beneficial seed dispersers of pepper fruits, as well as fruit pests such as insects and fungi. All field experiments will be conducted at the La Selva Biological Station in Costa Rica, an area where pepper plants and their associated fruit-feeding bats, insect pests and fungi are found in high abundance.The benefits of the study include an improved understanding of seed dispersal and the natural defense of fruits against pests -- two processes that are critical for plant survival and have direct relevance for agriculture and forest management. In addition, this study will create excellent opportunities for undergraduate and graduate student training due to its integrative approach that combines biology and chemistry. The research team will include students from both the US and Costa Rica, providing opportunities for international collaboration and cultural exchange. The results will be disseminated through scientific publications, as well as educational activities for K-12 students and the general public.