Biogeochemical and Ecological Impacts of Amphipod Circoviruses in Benthic Habitats

端足类圆环病毒对底栖栖息地的生物地球化学和生态影响

• 批准号: 1356964
• 负责人: Ian Hewson
• 金额: $ 61.91万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1356964&HistoricalAwards=false
• 关键词: Biogeochemical; Ecological; Impacts; Amphipod; Circoviruses

Overview: This project will investigate how circoviruses influence the herbivory/detritivory rates of benthic amphipods through the study of an experimental gradient of viral prevalence and by addition of cultivated viruses. The hypotheses to be tested are: H1: Circoviruses cause decreased detritivory and herbivory by infected amphipod hosts; H2: Circoviral impacts on amphipods result in decreased growth rate of sediment bacteria, decreased extracellular cellulose activity of sediment microorganisms, and decreased fluxes of oxidized inorganic nutrients from sediments into overlying waters; H3: Circoviruses negatively impact the nutritional quality of their hosts. These hypotheses will be tested by conducting sediment-water mesocosm experiments to assess the impacts of circoviruses on aquatic vegetation breakdown, and subsequent impacts on biogeochemistry, including bacterial production, efflux of reduced N into overlying waters, and production of dissolved organic C. Finally, this project will examine how circoviruses influence the nutritional quality of amphipods by examining elemental ratios of amphipod populations from high to low circoviral prevalence and experimentally infected amphipods. Data from these three approaches will be used to form a model of how circoviruses influence benthic foodwebs and biogeochemical cycles in sediment habitats. This study focuses on circoviruses within two ecologically sensitive amphipods that are crucial to ecosystem function: Diporeia (in Lake Michigan), which has experienced dramatic decline in abundance over the last 20 years within the Great Lakes, and Peramphithoe femorata, which is a major consumer of the environmentally threatened giant kelp Macrocystis pyrifera on the US West Coast.Intellectual Merit: Decades of research have identified the importance of viruses in aquatic ecology and biogeochemistry.However, most studies have focused on bacteriophage and viruses of eukaryotic microorganisms. Metazoa are important drivers of benthic biogeochemistry, where they cause bioirrigation of anoxic sediments, resuspension, settlement of particulate matter, facilitating nutrient fluxes from sediments to overlying waters, and potentially influencing ocean-scale processes like sediment denitrification. Circoviruses have been identified as a common constituent of crustacean viral assemblages, where they are well correlated with host death rates and population decline, and cultivated circoviruses cause death of arthropod cells. There is therefore a strong need to investigate how viruses impact the ecology of their crustacean hosts, and how in turn those impacts influence ecosystem function. Amphipods are important epifaunal constituents of benthic habitats, where they consume settled particulate matter and aquatic vegetation, which in turn influences its conversion to dissolved organic matter through microbial degradation. In turn their feeding activities stimulate benthic mineralization rates, and they are consumed by higher trophic levels. Therefore, amphipods link microbial to macrobial food webs in coastal and lake habitats. This project investigates how circoviruses infecting amphipods influence the flux of C through benthic ecosystems as a model of how viruses of metazoa influence biogeochemistry of aquatic ecosystems. The research will provide insight into how viruses influence aquatic biogeochemistry, opening up a new area of research into metazoan viruses in benthic ecosystems.Broader Impacts: The project has been designed to incorporate three broader impact activities. First, it will involve science teachers at the Newfield High School (Newfield, NY) and Oneida Lake Region high schools to directly involve and integrate high needs students into the research team to conduct experiments and laboratory analyses, culminating in presentation of their research activities to their peer group. Second, it will engage undergraduate students through summer internships at the Cornell Biological Field Station, and undergraduate researchers during the school year at Cornell to participate in the experiments and hone skills in scientific presentation. Third, it will develop extensive web-based outreach tools, including a website (incorporating live views of experiments), and social media pages targeting the general public and K-12 students. Finally, the proposed work will provide insight into the ecology of vulnerable aquatic ecosystems.

概述：该项目将通过研究病毒患病率的实验梯度并增加培养病毒的实验梯度来研究圆锥病毒如何影响底栖两栖类动物的草食/降低率。要测试的假设是：H1：虫病病毒导致受感染的两亲植物宿主的损失和草食性降低； H2：对两亲脚架的圆柱影响导致沉积物细菌的生长降低，降低沉积物微生物的细胞外纤维素活性，以及​​从沉积物中氧化的无机养分的通量减少，从沉积物中氧化，从沉积物中降低。 H3：圆柱病毒对宿主的营养质量产生负面影响。这些假设将通过进行沉积物 - 水中的实验来测试，以评估电路病毒对水生植被崩溃的影响，以及随后对生物地球化学的影响，包括细菌生产，包括细菌的外排，还原N到上面的水域中的n中排出，并通过研究元素的元素来影响元素的元素。从高循环病毒和实验感染的两亲脚架的两亲脚体种群。这三种方法的数据将用于形成一个模型，该模型是在沉积物栖息地中如何影响底栖食品韦伯和生物地球化学周期的模型。 This study focuses on circoviruses within two ecologically sensitive amphipods that are crucial to ecosystem function: Diporeia (in Lake Michigan), which has experienced dramatic decline in abundance over the last 20 years within the Great Lakes, and Peramphithoe femorata, which is a major consumer of the environmentally threatened giant kelp Macrocystis pyrifera on the US West Coast.Intellectual Merit:数十年的研究已经确定了病毒在水生生态学和生物地球化学中的重要性。但是，大多数研究都集中在真核微生物的噬菌体和病毒上。 Metazoa是底栖生物地球化学的重要驱动因素，它们会引起缺氧沉积物，重悬，颗粒物质的沉降，促进从沉积物到上层水的营养通量以及潜在影响海洋刻画过程等海洋刻画工艺等潜在的沉积物否定性等潜在的养分通量。虫病病毒已被确定为甲壳类病毒组合的共同组成部分，在那里它们与宿主死亡率和人口下降良好相关，并且培养的电路病毒会导致节肢动物细胞死亡。因此，非常需要研究病毒如何影响其甲壳类宿主的生态学，以及这些影响如何影响生态系统功能。两亲脚架是底栖生境的重要表现成分，它们消耗了沉降的颗粒物和水生植被，进而影响其通过微生物降解而转化为溶解有机物的转化。反过来，他们的喂养活动刺激了底栖矿化速率，并被较高的营养水平所消耗。因此，Amphipods将微生物与沿海和湖泊栖息地的大型食物网联系起来。该项目调查了感染两亲脚架的电路病毒如何影响C通过底栖生态系统的通量，以此作为Metazoa病毒如何影响水生生态系统生物地球化学的模型。该研究将提供有关病毒如何影响水生生物地球化学的洞察力，在底栖生态系统中开辟了新的对内唑病毒的研究领域。BRODERIMPACTS：该项目旨在纳入三种更广泛的影响活动。首先，它将涉及纽菲尔德高中（纽约州纽菲尔德）和奥尼达湖地区高中的科学教师，直接涉及并将高需求的学生纳入研究团队，以进行实验和实验室分析，从而最终向同伴组介绍他们的研究活动。其次，它将通过康奈尔生物野外车站的暑期实习和康奈尔大学学年的本科研究人员与本科生互动，以参加科学演示的实验和磨练技能。第三，它将开发广泛的基于Web的外展工具，包括网站（结合实验的实时视图）以及针对公众和K-12学生的社交媒体页面。最后，拟议的工作将洞悉脆弱的水生生态系统的生态。