ANT LIA: Collaborative Research: Adaptations of Southern Ocean Diatoms to Manganese Scarcity: Can Physiological Ingenuity Overcome Unfavorable Chemistry?

ANT LIA：合作研究：南大洋硅藻对锰稀缺的适应：生理学的独创性能否克服不利的化学因素？

• 批准号: 2149070
• 负责人: Nicholas Hawco
• 金额: $ 26.25万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2149070&HistoricalAwards=false
• 关键词: ANT; LIA; Collaborative; Research; Adaptations

The current understanding of what controls productivity in the Southern Ocean is based mostly on the scarcity of a metal compound needed for algal growth, Dissolved Iron in seawater. There is growing evidence that Manganese also plays a critical role in maintaining algal growth and if found in low concentrations can play a role in limiting primary productivity. As algal growth is a major player in absorbing carbon dioxide from the atmosphere, understanding what controls productivity increases our understanding of what role the Southern Ocean plays in the global carbon cycle. This study proposes to study the algal processes that take up Manganese in Antarctic diatoms, one of the main primary producers in the region. Another aspect will be to understand how Zinc, a micronutrient with similar dynamics than Manganese, can inhibit its uptake. The PIs propose lab experiments with cultured diatoms isolated from the Southern Ocean to obtain answers to their questions on micronutrient dynamics and will compare results from those obtained with a diatom species isolated from temperate waters. The proposed research will benefit NSF’s goals of understanding life in cold environments and how they differ from other parts of the ocean. This project will support two first-time early career scientists and a female researcher in Earth Sciences. Two graduate students will also be supported, and scientific techniques used in this research will be shared at open houses sponsored by the academic institutions and with local summer schools. This proposal represents collaborative research to explore manganese (Mn) limitation in Antarctic diatoms by two early career investigators. Diatoms are central players in the Southern Ocean carbon cycle, where the micronutrient chemistry is fundamentally different from other oceans. The Southern Ocean is characterized by widespread low Mn, coupled with high zinc (Zn). High Zn levels are potentially toxic to diatoms as Zn can competitively inhibit Mn uptake and metabolism, compromising the ability of building critical cellular components, thus impacting the biological pump. Using culture experiments with a matrix of micronutrient treatments (Mn, Zn, Fe) and irradiances, and using physiological and transcriptomic approaches, along with biochemical principles, the Principal Investigators will address the central hypothesis (diatoms from the Southern Ocean possess physiological mechanisms to low Mn/high Zn) to quantify rates of uptake and transporter binding constants. The transcriptomics approach will help to identify candidate genes that may provide Antarctic diatoms physiological mechanisms in low Mn/high Zn environment. The project does not require fieldwork but instead would make use of culture experiments with 4 diatom species (3 Antarctic, and 1 temperate). The proposed approach will also enable the goal of developing biomarker(s) for assessing Mn stress or Zn toxicity and results from the physiological experiments will help parameterize models of micronutrient limitation in the Southern Ocean.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.

当前对控制南方生产力的最新理解主要是基于藻类生长所需的金属化合物的稀缺性，在海水中溶解铁。越来越多的证据表明，锰在维持藻类生长中也起着至关重要的作用，如果在低浓度中发现可以在限制初级生产力中发挥作用。由于藻类生长是吸收大气中吸收二氧化碳的主要参与者，因此了解哪种控制生产力会增加我们对南洋在全球碳循环中扮演什么角色的理解。这项研究的提议研究了在南极硅藻中占用锰的藻类过程，这是该地区主要生产者之一。另一个方面将是了解锌是一种比锰相似的微量营养素，可以抑制其摄取。 PIS提案实验室实验与从南大洋分离出的培养硅藻，以获取其有关微量营养素动力学问题的答案，并将比较从温度水域分离的硅藻物种获得的结果。拟议的研究将使NSF在寒冷环境中了解生活的目标以及它们与海洋其他地区的区别。该项目将支持两位初次的早期职业科学家和一名地球科学的女性研究员。还将支持两名研究生，这项研究中使用的科学技术将在学术机构和当地暑期学校赞助的开放式房屋中共享。该提案代表了两名早期职业研究人员在南极硅藻中探索锰（MN）限制的合作研究。硅藻是南大洋碳循环中的核心参与者，那里的微量营养素化学与其他海洋根本不同。南大洋的特征是广泛的低Mn，以及高锌（Zn）。高Zn水平可能对硅藻有毒，因为Zn可以竞争地抑制MN的吸收和代谢，从而损害构建关键细胞成分的能力，从而影响生物泵。 Using culture experiments with a matrix of micronutrient treatments (Mn, Zn, Fe) and irradiances, and using physical and transcriptomic approaches, along with biochemical principles, the Principal Investigators will address the central hypothesis (diatoms from the Southern Ocean Possess Physiological Mechanisms to low Mn/high Zn) to quantify rates of uptake and transporter binding constants.转录组学方法将有助于确定可能在低Mn/高Zn环境中提供南极硅藻物理机制的候选基因。该项目不需要现场工作，而是使用具有4种硅藻种（3种南极和1个温度）的培养实验。拟议的方法还将实现开发生物标志物来评估MN压力或Zn毒性的目标，并且物理实验的结果将有助于参数化南大洋中微量营养素限制的模型。该奖项反映了NSF的法定任务，并通过使用基金会的知识优点和广泛影响来评估，认为NSF的法定任务是宝贵的。