权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Dissecting, and revealing the controls on, the group-specific CO2 fixation budget of the Atlantic Ocean

剖析并揭示对大西洋特定群体二氧化碳固定预算的控制

基本信息

批准号：
NE/G005125/1
负责人：
David Scanlan
金额：
$ 39.76万
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2009
资助国家：
英国
起止时间：
2009 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FG005125%2F1
关键词：
Dissecting revealing controls group specific

项目摘要

The oceans play a major role in determining world climate. In part this is due to the production of oxygen and the consumption of carbon dioxide (CO2) by very small, single celled photosynthetic organisms, the picophytoplankton. Picophytoplankton biomass is dominated by three main groups: the prokaryotic genera Prochlorococcus and Synechococcus, and eukaryotes comprising cells <5 micrometres in size. However, little is known of what goes on inside the picophytoplankton 'black box' particularly with respect to the distribution of carbon biomass and group-specific primary production, information which is fundamental to understanding the roles of these groups in the global C cycle. Very recently our team has optimised utilisation of radiotracer incubation-flow cytometric sorting technology, to reveal group-specific CO2 fixation rates at several stations in the North Atlantic. As well as revealing variability in group-specific CO2 fixation rates between sites this data reiterates the importance of the eukaryotic fraction in primary production estimates (contribution 25-50% dependent on location) even though numerically they are vastly outnumbered by their prokaryotic counterparts. Here, we propose to extend this work so that for the first time we can reveal group-specific CO2 fixation rates at the basin scale, as well as in both surface waters and at the deep chlorophyll maximum (DCM). We will perform this work along an Atlantic Meridional Transect, which traverses the Atlantic Ocean between the UK and the Falkland Islands, and in consecutive years, so that i) a complete group-specific CO2 fixation budget of the Atlantic Ocean is attained and ii) inter-annual variability can be assessed. Moreover, we will examine the precise contribution of different taxonomic lineages to the picoplankton group rates using fluorescent in situ hybridisation of sorted populations and lineage-specific oligonucleotide probes for the prokaryotic genera (Synechococcus and Prochlorococcus) or class-specific probes for the photosynthetic picoeukaryote (PPE) fraction. Hence, this project will provide fundamental information of the major 'players' and routes of CO2 fixation in situ, a process that underpins marine C cycling. Furthermore, we will investigate environmental control of group-specific C fixation rates using on-board bottle experiments following either nutrient addition or shifts in irradiance. This will allow us to understand how environmental perturbation controls the CO2 fixation potential of specific groups. We will couple this latter work with a functional genomics (transcriptomics) approach specifically targeted at the PPE fraction to provide a complementary molecular assessment of the potential regulatory factors controlling this group. This is based on the idea that transcriptional profiling will 'let the organism inform us of the key environmental parameters that these organisms are responding to'. Taken together this work will make major inroads in our understanding of the routes and controls of marine CO2 fixation, information which is essential for a predictive understanding of marine C cycling.

海洋在决定世界气候方面发挥着重要作用。这部分是由于非常小的单细胞光合生物（picophytoplankton）产生氧气和消耗二氧化碳（CO2）。浮游藻类生物量主要由三大类组成：原核原绿球藻属和聚球藻属，以及由小于5微米的细胞组成的真核生物。然而，知之甚少的picophytoplankton的“黑匣子”内发生了什么，特别是相对于碳生物量和组特定的初级生产，信息，这是了解这些群体在全球碳循环中的作用是至关重要的。最近，我们的团队优化了放射性示踪剂孵育流式细胞分选技术的利用，以揭示北大西洋几个站的群体特异性CO2固定率。以及揭示组特定的CO2固定率网站之间的变化，该数据重申了真核部分在初级生产估计的重要性（贡献25-50%，取决于位置），即使在数量上，他们大大超过了他们的原核对应物。在这里，我们建议扩展这项工作，使我们第一次可以揭示组特定的CO2固定率在流域尺度，以及在地表沃茨和深叶绿素最大值（DCM）。我们将执行这项工作沿着大西洋子午线样带，横跨英国和福克兰群岛之间的大西洋，并在连续几年，以便i）一个完整的组特定的CO2固定预算的大西洋是实现和ii）年际变化可以评估。此外，我们将研究不同的分类谱系的picoplankton组率使用荧光原位杂交的分类种群和谱系特异性寡核苷酸探针的原核生物属（聚球藻和原绿球藻）或类特异性探针的光合picoeukaryote（PPE）馏分的精确贡献。因此，该项目将提供主要的“球员”的基本信息和CO2固定在原地，一个过程，支持海洋碳循环的路线。此外，我们将调查环境控制组特定的固碳率使用车载瓶实验后，无论是营养添加或辐照度的变化。这将使我们了解环境扰动如何控制特定群体的CO2固定潜力。我们将耦合后一项工作与功能基因组学（转录组学）的方法，专门针对PPE部分，以提供一个互补的分子评估控制这一组的潜在调控因素。这是基于这样的想法，即转录谱将“让生物体告诉我们这些生物体正在响应的关键环境参数”。总之，这项工作将使我们的理解的路线和控制海洋CO2固定，信息是必不可少的海洋C循环的预测性理解的重大进展。