Collaborative Research: RUI: Implications of bacterially driven cross-kingdom chemical interactions

在进化史上，微生物与更大、更复杂的生物有着密切的联系，通常是由营养物质的互利交换驱动的。分析技术的进步表明，许多宿主与细菌的相互作用受到小分子的严格调控，这些小分子充当化学信使。然而，如何在细胞水平上将这些相互作用转化为对整个社区和生态系统的影响仍然是一个持续的挑战，需要跨学科的合作。一幅新出现的图景表明，海洋细菌在与藻类等宿主的相互作用中并非被动；相反，细菌会主动调节有机物的流动，这取决于它们如何部署自己的化学武器库。这个跨学科团队将开发新的方法来追踪和翻译模式藻类宿主和相关细菌之间复杂的化学信号。荧光生物传感器的新方法将量化细菌在细胞水平上产生的化学信号，其释放操纵宿主生理。宿主对化学物质的反应将通过测量宿主蛋白质、RNA和代谢物的变化来评估。这项工作支持在化学、生物和环境科学领域对代表性不足/资源不足的博士后和本科生进行培训和指导。四名博士后研究人员将与哈弗福德学院的教职员工一起参与以课程为基础的本科研究体验，目的是与学生建立支持性的学者-教师指导网络，并提供公平和包容的课程设计培训，使学者成为更能反思、更投入、更有效的教师。所有四个pi将开发基于会议的体验讲习班，以提供职业发展。微生物已经成为海洋系统中的关键角色，它们与真核浮游植物形成了复杂的关系。这些相互作用范围从共生到致病，并通过形成群落和影响海洋营养物生物地球化学命运的小分子化学信使的动态交换受到严格调节。阐明化学信号交换和破译细菌-浮游植物相互作用的环境驱动因素的努力是有限的，并且遇到了重大的技术挑战。最近，两种化学信使，四溴吡啶（TBP）和2-heptyl-4-喹诺酮（HHQ），都是由全球分布的海洋伽马变形菌假异单胞菌产生的，已被确定以不同的方式控制其相关的，形成开花的单细胞藻类宿主Emiliania huxleyi的生理。本研究中概述的实验准备梳理定义这种模式宿主-细菌共生的代谢景观，并详细说明化学信使何时以及如何诱导宿主代谢重编程，从而导致生态系统水平的后果。将实现三个协同目标：首先，将根据营养变化测量TBP和HHQ的产生和吸收，并使用生物传感器在单细胞水平捕获HHQ的产生。在第二个目标中，实验将通过建立赫胥黎鳗对piscicida和HHQ的代谢组学和蛋白质组学响应，同时跟踪piscicida对赫胥黎鳗衍生代谢物的吸收，揭示代谢串讯。第三，实验将利用电子显微镜研究HHQ是否能阻止赫胥黎大肠杆菌的病毒进入，这说明在HHQ存在的情况下，病毒诱导的赫胥黎大肠杆菌死亡被阻止了。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。

Over evolutionary history, microbes have evolved in close association with larger, more complex organisms, often driven by the mutually beneficial exchange of nutrients. Advancements in analytical techniques have revealed that many host-bacterial interactions are tightly regulated by small molecules, acting as chemical messengers. Yet, connecting how these interactions at the cellular level translate to impacts on whole communities and ecosystems remains an ongoing challenge necessitating cross-disciplinary collaboration. A newly emerging picture suggests that marine bacteria are not passive in their interactions with hosts such as algae; rather bacteria actively mediate the flow of organic matter depending on how they deploy their chemical arsenal. The assembled interdisciplinary team will develop new methods to track and translate complex chemical signals between a model algal host and associated bacteria. New methodologies in fluorescent biosensors will quantify bacterial production of chemical signals at the cellular level, whose release manipulates host physiology. How the host responds to the chemicals will be assessed by measuring changes in the host's proteins, RNA, and metabolites. This work supports the training and mentoring of underrepresented/underresourced postdoctoral and undergraduate trainees in themes bridging the chemical, biological, and environmental sciences. Four postdoctoral investigators will participate in course-based undergraduate research experiences with Haverford faculty with the goal of building supportive scholar-teacher mentoring networks with students and providing training in equitable and inclusive course design so that the scholars becoming more reflective, engaged, and effective teachers. All four PIs will develop conference-based experiential workshops to provide career development.Microbes have emerged as key players in marine systems where they form complex relationships with eukaryotic phytoplankton. These interactions range from symbiotic to pathogenic and are tightly regulated through the dynamic exchange of small molecule chemical messengers that shape communities and influence the biogeochemical fate of oceanic nutrients. Efforts to elucidate the exchange of chemical signals and decipher the environmental drivers of bacterial-phytoplankton interactions are limited and met with substantial technical challenges. Recently, two chemical messengers, tetrabromopyrrole (TBP) and 2-heptyl-4-quinolone (HHQ), both produced by the globally distributed marine gamma proteobacterium, Pseudoalteromonas, have been identified to govern the physiology of its associated, bloom-forming single-cell algal host, Emiliania huxleyi, with contrasting modalities. Experiments outlined in this study are poised to tease apart the metabolic landscape defining this model host-bacterial symbiosis, and detail when and how chemical messengers induce host metabolic reprogramming resulting in ecosystem level consequences. Three synergistic aims will be accomplished: in the first, TBP and HHQ production and uptake will be measured in response to nutrient variability and HHQ production will be captured at the single-cell level using biosensors. In the second aim, experiments will reveal metabolic cross-talk by establishing the metabolomic and proteomic response of E. huxleyi to both P. piscicida and HHQ, while tracking P. piscicida uptake of E. huxleyi-derived metabolites. In the third, experiments will investigate if HHQ prevents E. huxleyi viral entry using electron microscopy, accounting for an earlier observation that viral-induced mortality of E. huxleyi is stalled in the presence of HHQ.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.