RAPID: Synechococcus diversity and Fe stress and the relationship to dissolved metals in the Eastern Tropical South Pacific

单细胞蓝细菌聚球藻是海洋中分布最广、数量最多的光合生物之一，对海洋初级生产有重要贡献。它也非常多样化，迄今已确定了16个分支。然而，这种多样性尚未与具体的、明确界定的生态位相关联。为了确定聚球藻多样性的重要性，定义这些生态位是很重要的，即，是否存在于某一区域的进化枝对该区域的地球化学循环有很大的影响？与此同时，还必须确定分支的分布，以便更清楚地了解聚球藻在海洋中的作用，以及它在未来可能如何变化。在一个资助的项目中，“铁（Fe）在控制海洋聚球藻OCE-0825922的原位分布和活动中的作用”研究人员Jill A Sohm（J.A.S.）为了更好地定义聚球藻属的许多分支的生态小生境，和埃里克·韦伯一直在绘制聚球藻属分支在西太平洋、北大西洋和南大西洋以及洛杉矶海岸的分布图。在这个项目中，Webb和Sohm将参加2010年2月在东热带南太平洋（ETSP）进行的一次研究巡航，这是一个数据贫乏的地区，对微蓝细菌的生态学知之甚少。虽然已经表明，来自进化枝四的聚球藻在拟议的巡航以南的上升流区域占主导地位，但离岸较远的种群多样性却不那么明确。这次巡航将允许将目前的聚球藻分支分布数据库扩展到几乎没有数据的地区，并在现有项目中增加实验性实地工作，测试铁，光，温度和营养物质对实地种群多样性的具体影响。这些数据与同期实验室研究相结合，将提供深入了解海洋变化的潜力，影响分布和活动的聚球藻。除了定义的作用和影响，铁限制海洋聚球藻的活动和多样性的领域，该项目将开发现场培养测试，定量PCR为基础的铁应力诊断，将提供给社会。此外，研究人员将试图从该地区分离并提供聚球藻菌株;因为这种代表并不存在。维护和增加韦伯实验室的培养物收集是海洋学界的一项重要服务，因为这些菌株被免费发送给任何要求它们的研究人员。这次航行获得的元数据将存入国家数据库，与海洋学界共享。最后，该项目将为一名博士后J.A.S.提供宝贵的研究巡航经验和职业发展，还有一个研究生

The unicellular cyanobacterium Synechococcus is one of the most widespread and abundant photosynthetic organisms in the ocean, contributing substantially to marine primary production. It is also extremely diverse, with 16 clades identified so far. This diversity, however, has yet to be correlated with specific, well-defined ecological niches. It is important to define what these ecological niches are in order to determine the significance of Synechococcus diversity, i.e., does the clade present in a certain regime have a large impact on biogeochemical cycling in that area? In parallel, the distribution of the clades must also be defined, to able to understand more clearly the role of Synechococcus in the ocean, and how it might change in the future. In a the funded project, "The role of iron (Fe) in controlling in situ distributions and activities of marine Synechococcus OCE-0825922" investigators Jill A Sohm (J.A.S.) and Eric Webb have been mapping the distribution of Synechococcus clades in the western Pacific, the North and South Atlantic, and off the coast of Los Angeles, in order to better define the ecological niches of the many clades of Synechococcus. In this project, Webb and Sohm will participate in a research cruise occurring in February 2010 in the Eastern Tropical South Pacific (ETSP), a data poor region with little known about the ecology of its picocyanobacteria. While it has been shown the Synechococcus from clade four dominate the upwelling region farther south of the proposed cruise, the diversity of the population farther offshore is much less well defined. This cruise would allow expansion of the current database of Synechococcus clade distribution to an area where there is little to no data, and add experimental field work to an existing project, testing the specific affects of Fe, light, temperature and nutrients on the diversity of field populations. These data combined with concurrent lab research will provide insight into the potential of oceanic change to affect the distribution and the activity of Synechococcus.In addition to defining the role and impact of Fe limitation on marine Synechococcus activity and diversity in the field, this project will develop field incubation-tested, quantitative PCR-based Fe stress diagnostics that will be available to the community. Furthermore, the investigators will attempt to isolate and make available Synechococcus strains from the region; as such representatives are not in existence. The upkeep and addition to the culture collection in the Webb lab is an important service for the oceanographic community, as these strains are sent to any researcher that requests them without charge. Metadata obtained on this cruise will be shared with the oceanographic community by depositing them in a national database. Lastly this project will provide valuable research cruise experience and career development for one post-doctoral fellow, J.A.S., and one graduate student.