EAGER: Exploring Links between Iron and Phosphorus Nutrition of Antarctic Marine Phytoplankton

EAGER：探索南极海洋浮游植物铁和磷营养之间的联系

• 批准号: 2207011
• 负责人: Julie Granger
• 金额: $ 18.53万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207011&HistoricalAwards=false
• 关键词: EAGER; Exploring; Links; between; Iron

Phytoplankton are microscopic single-celled plants that grow at the sun-lit surface of the ocean. In the Southern Ocean around Antarctica, phytoplankton live in sub-optimal conditions because the amount of iron in seawater is insufficient for growth. Moreover, the chemical composition of Southern Ocean phytoplankton is distinct from that in other ocean regions, with a higher proportion of phosphorus relative to other elements, a characteristic that ultimately influences the distribution of nutrients ocean-wide. The researchers hypothesize that the high phosphorus composition of phytoplankton in the Southern Ocean is caused by their low iron content. Specifically, they postulate that a phosphorus-rich molecule, phytic acid, is synthesized by phytoplankton in order to assist in the storage of iron in designated cellular compartments, such as vacuoles. Recent observations show that some phytoplankton can absorb phytic acid, suggesting that it may be produced by certain species. Phytic acid is pervasive in soils, wherein it aids absorption of iron via plant roots and could similarly help phytoplankton in the Southern Ocean acquire iron via the cell membranes. This project benefits the National Science Foundation's goals of improving understanding of interactions between the Southern Ocean and the global ocean, of expanding fundamental knowledge of Antarctic biota and associated processes by focusing on phytoplankton species unique to the Antarctic. As part of this project, the Department of Marine Sciences from the College of Liberal Arts and Sciences at the University of Connecticut will sponsor the recruitment, relocation and mentorship of a graduate student under-represented in the sciences.This project aims to determine whether the unusual elemental composition of phytoplankton at the Southern Ocean is a result of anemia. The work will query whether inositol hexakisphosphate (phytic acid) aids Antarctic phytoplankton acquire and store iron, resulting in an elevated fraction of cellular phosphorus relative to other elements. The researchers, including a graduate student, will conduct laboratory culture experiments with phytoplankton strains isolated from the Southern Ocean. They will grow cells in iron- deficient versus iron-replete media to see if their phosphorus content is higher in iron-deficient conditions. They will test whether cells grown with sufficient phosphorus acquire more iron, allowing them to grow better in iron-deficient conditions than cells deriving from phosphorus-poor conditions. They will also query whether cells grown in iron-deficient conditions achieve faster growth rates in the presence of phytic acid. Results will inform the design of CRISPR mutants with which to investigate phosphorus and iron co-metabolism in Antarctic marine phytoplankton.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

浮游植物是在海洋阳光表面生长的微型单细胞植物。在南极洲周围的南大洋中，浮游植物居住在亚最佳条件下，因为海水中铁的量不足以生长。此外，南大洋浮游植物的化学组成与其他海洋地区的化学成分不同，相对于其他元素，磷的比例较高，这种特征最终会影响养分范围的养分。研究人员假设南大洋中浮游植物的高磷组成是由低铁含量引起的。具体而言，他们假设富含磷的分子是植物酸，是由浮游植物合成的，以协助在指定的细胞隔室中储存铁，例如液泡。最近的观察结果表明，某些浮游植物可以吸收植酸，这表明它可能由某些物种产生。植酸在土壤中普遍存在，其中它有助于通过植物根部吸收铁，并且可以类似地帮助南大洋中的浮游植物通过细胞膜获得铁。该项目有利于国家科学基金会通过关注南极独特的浮游植物物种来提高对南方海洋与全球海洋之间相互作用的理解，扩大南极生物群和相关过程的基本知识的目标。作为该项目的一部分，康涅狄格大学文科与科学学院的海洋科学系将赞助一名研究生的招聘，搬迁和指导，在科学中代表性不足。该项目旨在确定南部海洋中的Phytoplankton的异常元素成分是否是由Onemia的phytoplankton组成。这项工作将查询肌醇六磷酸（植酸）是否有助于南极浮游植物获取并储存铁，从而导致细胞磷的比例升高相对于其他元素。包括研究生在内的研究人员将通过从南大洋分离的浮游植物菌株进行实验室培养实验。它们将在铁缺乏培养基与铁含量的培养基中生长细胞，以查看其磷含量是否较高。他们将测试用足够的磷生长的细胞是否获得更多的铁，从而使其在缺铁条件下比衍生磷贫困条件的细胞更好地生长。他们还将查询在缺铁条件下生长的细胞在存在植酸的情况下达到更快的生长速率。结果将为CRISPR突变体的设计提供信息，以研究南极海洋植物浮游生物中的磷和铁的合用代谢。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的审查标准通过评估来进行评估的。