Dimensions:Collaborative Research: Oligotrophic phytoplankton community response to changes in N substrates and the resulting impact on genetic, taxonomic and functional diversity

维度：合作研究：寡营养浮游植物群落对氮底物变化的反应及其对遗传、分类和功能多样性的影响

• 批准号: 1241221
• 负责人: Jonathan Zehr
• 金额: $ 128.59万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1241221&HistoricalAwards=false
• 关键词: Dimensions; Collaborative; Research; Oligotrophic; phytoplankton; Dimensions; Collaborative; Research; Oligotrophic; phytoplankton

Intellectual merit. Marine phytoplankton are a diverse group of Prokaryotic and Eukaryotic unicellular organisms that account for approximately 50% of global carbon fixation. Nitrogen (N) is an essential element for microbial growth, but concentrations of bioavailable nitrogen in vast regions of subtropical ocean gyres are extremely low (submicromolar to nanomolar concentrations), and generally limit phytoplankton growth. Phytoplankton taxa differ in their genetic capabilities to take up and assimilate nutrients, and thus competition for different chemical forms of N (NH4+, NO3- and urea) and supply of these N-containing compounds are important controls on phytoplankton growth, productivity, and ultimately ecosystem function. The form and supply of N to phytoplankton have already been altered by anthropogenic activities, and with increasing environmental perturbations the effects will accelerate. To date however, there is limited information on how the N forms and fluxes impact the marine phytoplankton community composition and primary production. Similarly, determining the mechanisms of the response are crucial to assessing how ocean ecosystem function will respond to global climate change. This project seeks to determine how taxonomic, genetic and functional dimensions of phytoplankton diversity are linked with community-level responses to the availability of different N substrates (NH4+, NO3-, and urea) in one of Earth's largest aquatic habitats, the North Pacific Subtropical Gyre. The project will characterize phytoplankton community composition change and gene expression, photosynthetic performance, carbon fixation, and single-cell level N and C uptake in different taxa within the phytoplankton assemblage in response to different N compounds. The research project is unique in investigating community-to-single-cell level function and species (strain)-specific gene expression patterns using state-of-the-art methods including fast repetition rate fluorometry, nanoscale secondary ion mass spectrometry and a comprehensive marine microbial community microarray. The results will provide predictive understanding of how changes in the availability of key nitrogen pools (N) may impact phytoplankton dynamics and function in the ocean.Broader impacts. This project seeks to understand the ecological basis linking the metabolism of N to phytoplankton biodiversity in the open ocean. The underlying concept that links ecological competition for nutrients (in this case N) to phytoplankton diversity will provide a universal framework for understanding how ecosystem functions are linked to biodiversity. By applying state-of-the-art molecular and genetic methods to address ecological questions, the project seeks to develop an innovative workflow to assess eukaryotic and prokaryotic gene functions in the environment, and provides modern analytical and bioinformatic training for graduate students and postdoctoral researchers. The microarray tool has been designed by involving the larger marine microbiology community and is available to the greater scientific community, and this project is one of the first implementations. The fundamental concepts of microbial ecology and genomics will be used in educational activities in undergraduate and graduate-level classes as well as research training for undergraduates and graduates. Students and the postdoctoral researcher supported by this project will be engaged in development of microbiological and molecular biological displays and presentations at the Exploratorium, a science museum in San Francisco, California. Project personnel will collaboratively develop modules for the Exploratorium. The Exploratorium partnership will provide a mechanism for educational outreach for students and post-docs, as well as an efficient means to communicate the importance of ocean microbes and genomics to the public (over 600,000 visitors per year). The PIs will work with the education team in the Center for Microbial Oceanography: Research and Education (C-MORE) scholars program, at the University of Hawaii, to recruit an undergraduate student to participate in this project. The C- MORE scholars program seeks to promote workforce diversity by identifying faculty mentors to work with students of traditionally underrepresented backgrounds in the STEM disciplines.Integration. This project integrates multiple perspectives on microbial biodiversity. The project seeks to understand how nitrogenous nutrients regulate the taxonomic, genetic, and functional diversity of phytoplankton communities through differential gene expression and functional properties of phytoplankton taxa.

智力优点。海洋浮游植物是一组多样的原核生物和真核单细胞生物，约占全球碳固定的50％。氮（N）是微生物生长的重要元素，但是在亚热带海洋回旋巨大地区，可生物利用的氮浓度极低（亚摩尔摩尔至纳摩尔浓度），并且通常限制浮游植物的生长。浮游植物分类群的遗传能力有所不同，可以吸收和吸收养分，从而竞争NH4+，NO3和尿素的不同化学形式的竞争，这些含N的化合物的供应是浮游植物群生长，生产力，生产率以及最终生态系统功能的重要控制。 n到浮游植物的形式和供应已经通过人为活性改变了，随着环境扰动的增加，效果将加速。但是，迄今为止，关于氮的形式和通量如何影响海洋浮游植物社区组成和初级生产的信息有限。同样，确定响应的机制对于评估海洋生态系统功能将如何响应全球气候变化至关重要。该项目旨在确定浮游植物多样性的分类，遗传和功能维度如何与社区级别对地球最大的水生栖息地之一的不同N底物（NH4+，NO3-和尿素）的可用性（NH4+，NO3-和尿素）的响应有关。该项目将表征浮游植物群落组成的变化和基因表达，光合作用性能，碳固定以及在浮游植物组合中不同分类单元中的N和C摄取单细胞水平的N和C摄取，以响应不同的N化合物。该研究项目在研究社区到单个细胞水平的功能和物种（菌株）特定基因表达模式中是独一无二的，其中包括快速重复速率荧光测定法，纳米级次级离子质谱法和全面的海洋微生物群落群落微阵列。结果将对关键氮池（N）的可用性变化如何影响浮游植物的动态和功能在海洋中的功能。该项目旨在了解将n与开阔海洋中的浮游植物生物多样性联系起来的生态基础。将营养生态竞争（在这种情况下）与浮游植物多样性联系起来的基本概念将为了解生态系统功能如何与生物多样性相关联。通过应用最先进的分子和遗传学方法来解决生态问题，该项目旨在开发创新的工作流程，以评估环境中的真核和原核基因的功能，并为研究生和博士后研究人员提供现代的分析和生物信息培训。微阵列工具是通过参与更大的海洋微生物学界而设计的，并且可供更大的科学界使用，该项目是最早的实施之一。微生物生态学和基因组学的基本概念将用于本科和研究生级课程的教育活动，以及针对本科生和毕业生的研究培训。该项目支持的学生和博士后研究人员将在加利福尼亚州旧金山的科学博物馆Exploratorium上开发微生物和分子生物学展示和演示。项目人员将协作开发探险家的模块。 Exploratorium合作伙伴关系将为学生和毕业后的教育外展提供一种机制，以及一种有效的手段，可以向公众传达海洋微生物和基因组学的重要性（每年超过60万名访客）。 PIS将与微生物海洋学中心的教育团队合作：夏威夷大学的研究与教育学者计划（C-MORE）学者计划，招募一名本科生参加该项目。 C-更多的学者计划旨在通过确定教师的导师与STEM学科中传统代表性不足的背景的学生合作来促进劳动力多样性。该项目集成了有关微生物生物多样性的多种观点。该项目试图了解氮营养如何通过浮游植物分类群的差异基因表达和功能特性来调节浮游植物群落的分类，遗传和功能多样性。