Collaborative Research: From cooperation to exploitation: context-dependent effects of nectar microbes on pollination mutualisms

合作在生态系统中无处不在；然而，即使面对作弊，它是如何继续坚持下去的，仍然是一个谜。该项目将探索微生物是否以及如何影响植物和驻留在花蜜中的微生物作为模型系统的合作。在不同的系统中，已经观察到共生物种窃取花卉资源而不提供授粉服务作为回报。该项目结合了落基山脉的野花群落、花卉访客和相关微生物的实地实验。主要目的是表征(1)蜜源微生物群落结构的驱动因素；(2)花蜜微生物对访花者行为的影响；(3)微生物和访客行为对植物繁殖的影响。更广泛的影响包括学生培训，公众宣传，以及提高对主要生态系统服务：授粉的理解。该项目将培养本科生、一名研究生和一名博士后。通过与一家非营利性博物馆的合作，以及与中学和暑期科学营的合作，计划进行公众宣传。植物、传粉者和花蜜掠夺者之间的相互作用长期以来一直是探索合作与冲突状态之间生态转变的重要模型系统。然而，尽管他们进行了广泛的研究，但令人惊讶的是，这些状态之间转换的机制以及其中的恒常性仍然不清楚。花蜜微生物代表了尚未充分研究但潜在的重要相互作用，它们可能会影响采花者决定合作或欺骗的觅食条件。本项目将(1)采用培养依赖和培养独立的方法来表征五种山地野花在合法与花蜜掠夺花访问后的花蜜微生物群；(2)研究花蜜微生物对花香、花蜜化学和访花者行为的影响；(3)测量微生物和访花群落对植物繁殖组分的反馈。通过研究花蜜微生物及其对花型的影响，以及它们是加强还是促进授粉的破坏，我们将更广泛地了解影响植物繁殖和授粉相互关系的因素。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cooperation is ubiquitous across ecological systems; yet how it continues to persist, even in the face of cheating, remains an enigma. This project will explore if and how microbes affect cooperation using plants and the microbes that reside in floral nectar as a model system. Across different systems, mutualistic species have been observed to steal floral resources without providing pollination services in return. This project uses a combination of field experiments across a community of wildflowers, floral visitors, and associated microbes in the Rocky Mountains. The main goals are to characterize (1) drivers of nectar microbial community structure; (2) how nectar microbes influence behaviors displayed by floral visitors; and (3) how microbes and the visitor behaviors affect plant reproduction. Broader impacts include student training, public outreach, and improved understanding of a major ecosystem service: pollination. The project will train undergraduate students, a graduate student, and a postdoctoral researcher. Public outreach is planned through a partnership with a non-profit museum, as well as through work with middle schools and summer science camps.Interactions among plants, pollinators, and nectar robbers have long served as an important model system for exploring ecological shifts between states of cooperation and conflict. Yet, despite their extensive study, the mechanisms that underlie shifts between these states, and constancy within, remain surprisingly unclear. Nectar microbes represent understudied but potentially significant interactors that may shape the foraging conditions under which floral visitors may decide to cooperate or cheat. This project will (1) employ the use of culture-dependent and culture-independent approaches to characterize the nectar microbiome of five montane wildflowers after legitimate vs. nectar robber floral visits; (2) assess how nectar microbes influence floral odor, nectar chemistry, and visitor behaviors; and (3) measure feedbacks of the microbes and floral visitor community on components of plant reproduction. By studying nectar microbes, their impact on floral phenotype, and whether they reinforce or facilitate the breakdown of pollination, we will gain a broader understanding of the factors that shape plant reproduction and pollination mutualisms.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.