Dimensions: Collaborative Research: Assembly and function of nectar microbial communities

这个项目的目标是研究生活在花蜜中的微生物(生命太小而不容易被看到，比如酵母和细菌)的生态学。对于这种生物来说，花蜜是一个有趣的生存场所，因为它不会持续很长时间--大多数花朵只持续几天。然而，每一朵花都可以是一个复杂和不断变化的酵母和细菌“群落”的家园；它们是微型生态系统。科学家们将进行实验，以探索这些微生物是如何进入花蜜的，以及它们到达的顺序是否决定了最终生活在那里的微生物。因为每朵花都有自己独立的生态系统，科学家可以很容易地调整这些生态系统，这个研究系统是理解各种大小的生态系统可能如何发展的一个很好的系统。当试图帮助保护稀有物种并保持生态系统以造福人类和野生动物的方式运行时，这种理解是重要的。例如，在这个项目中，最终形成花的特定酵母菌和细菌可能会对传粉者造访的花产生很大影响，从而影响花的授粉效率。鉴于人类的食物在很大程度上依赖于农作物的授粉，了解什么可以导致更有效的授粉具有经济和社会意义。高中生将通过为期7周的暑期研究实习，在研究方面得到指导。研究生和博士后研究员将帮助指导这些高中生，并自己接受指导。将提供生物信息学工作坊，培训学生基本的数据分析技能。将对加州一种蜂鸟授粉灌木中的花蜜微生物进行野外观察、田间实验和实验室实验相结合。数据将通过构建植物-蜂鸟-花蜜微生物相互作用的模拟模型来整合，提供群落组装理论的测试。研究人员将整合生物多样性的遗传、系统发育和功能维度，研究(1)酵母遗传多样性和细菌系统发育多样性如何受开花物候的影响，(2)酵母遗传多样性和细菌系统发育多样性如何通过花蜜内的拮抗优先效应相互抑制，(3)酵母遗传多样性和细菌系统发育多样性如何通过改变花蜜中的花蜜化学来改变蜂鸟的觅食偏好，从而影响花的功能多样性，从而从花蜜化学、授粉成功和种子生产的角度影响花的功能多样性，以及(4)花的功能多样性如何通过改变酵母和细菌在花中的扩散来影响酵母遗传多样性和细菌系统发育多样性。

The goal of this project is to study the ecology of micro-organisms (life too small to be easily seen, like yeast and bacteria) that live in the nectar of flowers. Nectar is an interesting place for such organisms to live because it doesn't last long -- most flowers last only a few days. Yet, each flower can be home to a complex and changing "community" of yeast and bacteria; they are miniature ecosystems. Scientists will conduct experiments to explore how those micro-organisms get into nectar and whether the order in which they arrive determines the final set that end up living there. Because each flower contains its own separate ecosystem that can be easily tweaked by scientists, this study system is a good one for understanding how ecosystems of all sizes may develop. Such understanding is important when trying to help preserve rare species and to keep ecosystems functioning in ways that benefit both humans and wildlife. In this project, for example, the particular set of yeast and bacteria that end up in flowers may have a large impact on what pollinators visit flowers and thus on how effectively the flowers are pollinated. Given that a lot of what humans eat depends on pollination of crops, understanding what can lead to more effective pollination has both economic and social relevance. High-school students will be mentored in research through a 7-week summer research internship. Graduate students and postdoctoral fellows will help mentor those high school students and be mentored, themselves. Workshops on bioinformatics will be offered to train students in essential skills of data analysis.A combination of field observations, field experiments, and laboratory experiments will be conducted on nectar microbes associated with a hummingbird-pollinated shrub in California. Data will be integrated through construction of a simulation model of plant-hummingbird-nectar microbe interactions, providing tests of community assembly theory. Researchers will integrate genetic, phylogenetic and functional dimensions of biodiversity by studying how (1) yeast genetic diversity and bacterial phylogenetic diversity are influenced by flowering phenology, (2) yeast genetic diversity and bacterial phylogenetic diversity suppress each other through antagonistic priority effects within floral nectar, (3) yeast genetic diversity and bacterial phylogenetic diversity alter hummingbirds' foraging preference by modifying nectar chemistry as a result of growth in nectar, thereby affecting functional diversity of flowers in terms of nectar chemistry, pollination success, and seed production, and (4) how functional diversity of flowers feeds back to affect yeast genetic diversity and bacterial phylogenetic diversity via altered dispersal of yeast and bacteria across flowers.