Marine Viruses Infecting Phytoplankton: Host-Specificity, Temporal Variability, Decay Rates and Effects on Natural Phytoplankton Communities

这项研究计划有四个具体目标，它们将共同为有关感染浮游植物的本土海洋病毒的重要问题提供答案。首先，研究人员将确定已分离并感染真核和原核浮游植物的病毒的宿主特异性。将对每个病毒分离株进行筛选，以对抗与原始宿主具有密切和遥远亲缘关系的大量潜在宿主。第二，感染聚球藻的病毒的时间变异性。将每月在天然水域中通过菌斑分析进行测定。第三，萨特尔博士将确定三种病毒在自然水域中的衰减率(周转时间)，这三种病毒已经被分离并开发了空斑分析。第四，将确定自然病毒群落对浮游植物生产力和群落结构的影响。关于感染海洋浮游植物的病毒，人们几乎一无所知；然而，这项建议中包含的数据表明，病毒是重要的，可以影响碳固定的速度。这项研究将回答有关浮游植物与病毒相互作用和传染性病毒在海洋中持续存在的基本问题。只有这样的研究才能提供必要的数据，以便将病毒介导的过程纳入全球海洋营养和能量循环的综合模型。

There are four specific objectives to this research program which, together, will yield answers to important questions regarding indigenous marine viruses which infect phytoplankton. First, the investigator will characterize the host specificity of viruses that have been isolated and which infect eukaryotic and prokaryotic phytoplankton. Each of the viral isolates will be screened against a large number of potential hosts with close and distant phylogenetic relationships, to the original host. Second, the temporal variability of a virus which infects Synechococcus sp. will be determined monthly in natural waters by plaque assay. Third, Dr. Suttle will determine the decay rates (turnover times) in natural waters of three viruses which have been isolated and developed plaque assays for. Fourth, the effect of natural virus communities on phytoplankton productivity and community structure will be ascertained. Almost nothing is known about viruses which infect marine phytoplankton; yet, data included in this proposal suggests that viruses are important and can affect rates of carbon fixation. This research will answer fundamental questions concerning phytoplankton-virus interactions and persistence of infectious viruses in the sea. Only studies such as these will provide the requisite data to enable incorporation of viral-mediated processes into comprehensive models of nutrient and energy cycling in the global oceans.