Collaborative Research: The Role of Copper in the High Affinity Iron Uptake systems of Eukaryotic Marine Phytoplankton

合作研究：铜在真核海洋浮游植物高亲和力铁吸收系统中的作用

• 批准号: 0526704
• 负责人: Mark Wells
• 金额: $ 38.42万
• 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: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0526704&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Copper; Affinity

Iron enrichment of High Nitrate, Low Chlorophyll (HNLC) waters of the subarctic Pacific lead seed populations of Pseudo-nitzschia (pennate) diatoms to rapidly bloom. Recent findings from laboratory and field experiments show that Pseudo-nitzschia species posses the ability to grow on strongly complexed Fe (III), and that this ability is directly dependent on Cu availability. This Fe uptake system is induced under Fe-stress, and its efficiency contrasts what is known about other coastal diatoms. Genes homologous to high affinity Fe uptake proteins are found in T. pseudonana, and should be present in Pseudo-nitzschia species. Because T. pseudonana possesses putative genes for high-affinity Fe uptake proteins and can still be readily starved for Fe under normal laboratory culture conditions, it is implied that the Fe uptake system in T. pseudonana is incomplete, or that some environmental factor prevents induction or limits the functionality of the high affinity Fe uptake system in contrast to the highly efficient system in Pseudo-nitzschia. As a result, more molecular and physiological studies are needed to better ascertain the mechanism and functionality of the high affinity Fe uptake systems in eukaryotic diatoms such as T. pseudonana and Pseudo-nitzschia species. In this study, researchers at the University of California at Santa-Cruz and the University of Rhode Island will focus on understanding the relationship between Fe redox chemistry in seawater and the molecular, biologically mediated reactions that render Fe availability for uptake by eukaryotic phytoplankton. The team of scientists will establish whether or not the structural components of the high affinity Fe uptake system indicated by sequence homology can function in T. pseudonana and if the same components are present and can function in Pseudo-nitzschia spp. The researchers will also examine how the gene expression patterns of the high affinity iron uptake homologues are induced by Fe stress, and how the presence of these proteins correlates with the rates of Fe and Cu uptake in Pseudo-nitzschia spp. and T. pseudonana. In addition, the work will determine which cell fraction harbors this additional Cu quota and whether or not the increased Cu requirement of Pseudo-nitzschia under Fe stress occurs with other phytoplankton species in offshore waters. This work will be important to understanding the mechanistic controls that effect the Fe uptake of large diatoms, as well as provide insight into how the natural or anthropogenic fluxes of iron to HNLC waters influence the export of carbon to the deep ocean and effect the global climate. In terms of broader impacts, the project will provide the training, education, and research to a beginning female investigator, a Ph.D. student, and a graduate student. A high school teacher who will bring the field results to the science classroom will also participate in the project.

亚北极太平洋的高硝酸盐，低叶绿素（HNLC）水的铁富集，伪nitzschia（pennate）硅藻迅速开花的铁含量。实验室和现场实验的最新发现表明，伪nitzschia物种具有在强大的Fe（III）上生长的能力，并且这种能力直接取决于CU的可用性。 这种FE摄取系统是在FE压力下引起的，其效率对比了其他沿海硅藻的了解。 与高亲和力Fe摄取蛋白同源的基因在T. pseudonana中发现，应存在于伪nitzschia物种中。因为t. pseudonana具有针对高亲和力Fe摄取蛋白的假定基因，并且在正常的实验室培养条件下仍然很容易饿死Fe，因此暗示T. pseudonana中的Fe摄取系统不完整，或者某些环境因素会导致高度亲和力Feptake在相反系统中的高度诱导或限制对相反系统的功能。 结果，需要更多的分子和生理研究，以更好地确定真核硅藻（例如伪t。pseudonana和pseudo-nitzschia物种）中高亲和力Fe摄取系统的机制和功能。 在这项研究中，加利福尼亚大学圣克鲁兹分校和罗德岛大学的研究人员将重点放在了解海水中的Fe氧化还原化学与分子，生物学介导的反应之间的关系，这些反应使真核Phytoplankton的真核phytake摄取Fe的可用性。 科学家团队将确定序列同源性指示的高亲和力Fe摄取系统的结构成分是否可以在T. pseudonana中起作用，并且是否存在相同的组件并且可以在伪nitzschia spp中起作用。 研究人员还将研究如何通过Fe应力诱导高亲和力铁吸收同源物的基因表达模式，以及这些蛋白质的存在与伪nitzschia spp中的Fe和Cu摄取率如何相关。和T. Pseudonana。 此外，这项工作将确定哪种细胞分数还有这种额外的CU配额，以及在Fe胁迫下是否增加了伪nitzschia的CU需求增加，其他浮游植物物种在离岸水域的其他浮游植物物种发生。这项工作对于理解影响大硅藻的机械控制非常重要，并洞悉铁的天然或人为通量如何影响HNLC水域，影响碳的出口到深海并影响全球气候。 就更广泛的影响而言，该项目将为初学的女研究员提供培训，教育和研究。学生和研究生。将把现场成果带到科学课堂的高中老师也将参加该项目。