Controls on iron availability to marine phytoplankton

控制海洋浮游植物的铁利用率

• 批准号: NE/V01451X/1
• 负责人: Fengjie LIU
• 金额: $ 75.08万
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV01451X%2F1
• 关键词: Controls; iron; availability; marine; phytoplankton

Anthropogenic greenhouse gas emissions such as carbon dioxide (CO2) are causing climate change, global warming, and ocean acidification. Microscopic plants called phytoplankton, living in the surface oceans, sequester 50% of global CO2 and supply >50% of new nitrogen used for primary production. Other than light and major nutrients, phytoplankton growth is strongly influenced by availability of the metal iron (Fe), because the metal is essential for photosynthesis and nitrogen fixation, but is very scarce in the open ocean. Iron is so important that seeding the metal into Fe-poor areas has been proposed as a viable method for controlling climate change by enhancing bio-uptake of atmospheric CO2 by phytoplankton. In order to understand how Fe controls atmospheric CO2 levels and oceanic productivity, it is important to first attempt to understand the controls on availability of the metal to marine phytoplankton. The prevailing view is that metal bioavailability depends upon its chemical forms (i.e., metal speciation) in ambient bulk waters; however, data from our recent studies are inconsistent with the long-standing paradigm. In the proposed project, I will challenge this long-standing paradigm by studying the Fe speciation in the phycosphere, a micrometer scale space which directly surrounds a phytoplankton cell, through the use of novel nano-technologies and inter-disciplinary approaches. Phytoplankton directly take up nutrients including Fe from the phycosphere, rather than directly from bulk seawater, however the Fe speciation in this micro-scale space has not previously been studied. The lack of knowledge on phycosphere Fe speciation would potentially result in serious under or overestimation of oceanic Fe availability in current and future oceans, and lead to erroneous prediction of how ocean ecosystem responds to Climate Change. The interdisciplinary project will provide a new view on the fundamental processes in Fe acquisition by phytoplankton, and it will certainly help improve the capability and accuracy of international agencies such as the Intergovernmental Panel on Climate Change to assess the sensitivity of planetary system to Climate Change.

二氧化碳（CO2）等人为温室气体排放正在导致气候变化、全球变暖和海洋酸化。生活在海洋表面的微型浮游植物吸收了全球50%的二氧化碳，并提供了超过50%的用于初级生产的新氮。除了光和主要营养物质，浮游植物的生长受到金属铁（Fe）的影响，因为金属是光合作用和固氮所必需的，但在公海中非常稀缺。铁是如此重要，播种到铁贫地区的金属已被提出作为一个可行的方法来控制气候变化，通过提高浮游植物的大气CO2的生物吸收。为了了解铁如何控制大气中的二氧化碳水平和海洋生产力，重要的是要首先尝试了解海洋浮游植物的金属可用性的控制。普遍的观点是金属的生物利用度取决于其化学形式（即，金属形态）在周围散装沃茨;然而，我们最近的研究数据与长期存在的范式不一致。在拟议的项目中，我将挑战这个长期存在的范式，通过研究藻类圈中的铁形态，直接围绕浮游植物细胞的微米尺度空间，通过使用新的纳米技术和跨学科的方法。浮游植物直接从藻圈中吸收包括Fe在内的营养物质，而不是直接从散装海水中吸收，然而在这个微尺度空间中的Fe形态以前没有研究过。缺乏对藻圈铁形态的认识，可能会导致对当前和未来海洋铁有效性的严重低估或高估，从而导致对海洋生态系统对气候变化响应的错误预测。该跨学科项目将为浮游植物获取铁的基本过程提供新的视角，并将有助于提高政府间气候变化专门委员会等国际机构评估行星系统对气候变化敏感性的能力和准确性。

项目成果

Phycosphere pH of unicellular nano- and micro- phytoplankton cells and consequences for iron speciation.

• DOI: 10.1038/s41396-022-01280-1
• 发表时间: 2022-10
• 期刊: ISME JOURNAL
• 影响因子: 11
• 作者: Liu, Fengjie;Gledhill, Martha;Tan, Qiao-Guo;Zhu, Kechen;Zhang, Qiong;Salaun, Pascal;Tagliabue, Alessandro;Zhang, Yanjun;Weiss, Dominik;Achterberg, Eric P.;Korchev, Yuri
• 通讯作者: Korchev, Yuri