Collaborative Research: Diverse selective pressure on fruit chemical traits from mutualists and antagonists as a major driver of chemical evolution at the whole plant level

自然界中观察到的植物形态和功能的大部分多样性可以理解为与其他生物相互作用的共同进化结果。植物化学代表着一个被低估的多样性维度，它对调节植物相互作用并最终调节植物适合性至关重要。代谢组学是一个迅速发展的领域，在植物界描述了超过20万种次生代谢物。然而，关于热带物种的数据很少，绝大多数数据来自树叶。研究人员将利用代谢组学和生物信息学的最新进展、长期生态监测数据和实地研究来解释代谢组学数据，以提供关于植物防御进化的新的全植物视角。所有代谢组学数据都将公开，因为脊椎动物散布的成熟、肉质水果往往对微生物和昆虫有毒，但对脊椎动物无毒，使它们成为一种被低估的潜在药物的新来源。这些数据的公开存档将有助于潜在的药物发现。学生学者将在热带野外生物学和化学生态学的研究方法方面获得经验。结果将被用来为本科生物学课堂开发以学生为中心的、基于探究的课程材料。所有教育材料都将被翻译成西班牙语，并通过佛得角元素在拉丁美洲传播。为了交流研究，研究人员将与犹他州公共广播和影响媒体实验室合作制作多媒体，包括公共广播播客、短片和互动网站。植物生物学的一个基本问题是：为什么植物会产生如此多不同的化合物？植物化学生态学的大部分理论和实证研究都集中在叶片的防御上，而果实则通过更复杂的化学途径，同时防御敌人和吸引散布者。因此，研究人员假设，在植物中观察到的大部分次生代谢物多样性起源于水果。具体地说，该项目测试了这样一种假设，即水果化学性状上的不同选择压力是整个植物水平上植物化学多样化和进化的主要驱动因素。将使用比较代谢组学、观察性实地研究和系统发育控制实验的互补方法来检验这一假说。首先，将测量跨植物组织和物种的次生代谢物多样性的当代模式，以检测从水果-果食性相互作用中进行选择的特征。将采用代谢组学方法对50种在扩散模式上不同的乔木和灌木物种进行系统发育对照比较，以确定植物化学的特征。第二，水果和叶片次生代谢物多样性的模式如何在植物与水果和叶片消费者的相互作用中调节自然变化，将通过对这些相同物种的果肉、种子和叶片的果肉、种子和叶片的移除和损害的观察性研究来检验。第三，水果次生代谢物是否反映了对特定扩散模式的适应，将使用蝙蝠、鸟类和非生物分散物种的系统发育控制子集来实验确定。这项研究将在地球上研究最充分的热带森林系统之一，巴拿马的巴罗科罗拉多岛进行。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Much of the diversity in plant form and function observed in nature can be understood as the coevolutionary result of interactions with other living organisms. Plant chemistry represents an underappreciated dimension of diversity that is critical for mediating plant interactions and, ultimately, plant fitness. Metabolomics is a rapidly growing field with over 200,000 described secondary metabolites in the plant kingdom. However, there is a paucity of data for tropical species, and the vast majority of data are from leaves. The investigators will take advantage of recent advances in metabolomics and bioinformatics, long-term ecological monitoring data, and field studies to interpret the metabolomics data in ways that will provide a new whole-plant perspective on the evolution of plant defense. All metabolomics data will be made publicly available because ripe, fleshy fruits dispersed by vertebrates tend to be toxic to microorganisms and insects but non-toxic to vertebrates, making them an underappreciated and novel source of potential drugs. Public archival of these data will contribute to potential drug discovery. Student scholars will gain experience in research methods in tropical field biology and chemical ecology. Results will be used to develop student-centered, inquiry-based course materials for undergraduate biology classrooms. All educational materials will be translated into Spanish and disseminated in Latin America via Verde Elemental. To communicate research the investigators will collaborate with Utah Public Radio and Impact Media Lab to produce multimedia, including public radio podcasts, short-films, and an interactive website.A fundamental question in plant biology is: why do plants produce so many different chemical compounds? Most theory and empirical research in plant chemical ecology has focused on the defense of leaves, yet fruits thread a more complicated chemical path, simultaneously defending against enemies and attracting dispersers. Thus, the investigators hypothesize that much of the secondary metabolite diversity observed in plants has its origins in fruits. Specifically, the project tests the hypothesis that the diverse selective pressures on fruit chemical traits are a major driver of phytochemical diversification and evolution at the whole-plant level. Complementary approaches of comparative metabolomics, observational field studies, and phylogenetically-controlled experimentation will be used to test the hypothesis. First, contemporary patterns of secondary metabolite diversity across plant tissues and species will be measured to detect a signature of selection from fruit-frugivore interactions. A metabolomics approach to characterize phytochemistry of 50 phylogenetically-controlled comparisons of tree and shrub species that vary in dispersal mode will be carried out. Second, how patterns of fruit and leaf secondary metabolite diversity mediate natural variation in plant interactions with fruit and leaf consumers will be examined using an observational study of fruit removal and damage on pulp, seeds, and leaves for these same species. Third, whether fruit secondary metabolites reflect the adaptations to specific dispersal modes will be experimentally determined using a phylogenetically-controlled subset of bat-, bird-, and abiotically-dispersed species. The study will be conducted in one of the most well-studied tropical forest systems on Earth, Barro Colorado Island, Panama.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.