Scholarlink

<p>Phytoplankton play a key role in aquatic carbon cycling. The partitioning of algal-derived carbon between particulate organic carbon (POC) and dissolved organic carbon (DOC), and its further fractionation within the DOC pool, determines the fate of fixed carbon<i>.</i> However, the regulatory mechanisms of phytoplankton carbon allocation under climate change remain insufficiently explored. Here we investigated the carbon-partitioning response of a model algae, <i>Synechococcus</i> to three carbon dioxide (CO<sub>2</sub>) conditions in different future climate contexts. It was found that when CO<sub>2</sub> concentration increased to 850&#xa0;ppm, the carbon allocation patterns did not have significantly changed compared to that under current CO<sub>2</sub> concentration. In contrast, till the end of incubation, the extreme CO<sub>2</sub> concentration of 1370&#xa0;ppm led to significant decrease of 47.05% in the total organic carbon (TOC) concentration, with an increase of the concentration of extracellular DOC (DOC<sub><i>ex</i></sub>) and a reduction of POC. Notably, the final proportion of DOC<sub><i>ex</i></sub> increased to 44.32% from 22.66% of the DOC fraction. Our observed changes in carbon allocation of <i>Synechococcus</i> under extreme CO<sub>2</sub> concentrations suggests a reduced contribution of <i>Synechococcus</i> to aquatic carbon sequestration via the biological carbon pump through POC sinking, with a larger proportion of microalgal carbon being directly allocated to the surface DOC pool in the form of potentially recalcitrant DOC. Our study has important implications for accurately evaluating the role of <i>Synechococcus</i> in aquatic carbon sequestration in the context of future climate change.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Influence of simulated future climate CO2 scenarios on carbon allocation in a keystone cyanobacterium Synechococcus

  • 期刊论文

  • 发表日期：

    2025年8月28日

查看全文
  • Yanyan Zhang,
  • Lincheng Huang,
  • Yongxin Liu,
  • Tangcheng Li,
  • Hong Du,
  • Faming Wang,
  • Zhe Lu

摘要

Phytoplankton play a key role in aquatic carbon cycling. The partitioning of algal-derived carbon between particulate organic carbon (POC) and dissolved organic carbon (DOC), and its further fractionation within the DOC pool, determines the fate of fixed carbon. However, the regulatory mechanisms of phytoplankton carbon allocation under climate change remain insufficiently explored. Here we investigated the carbon-partitioning response of a model algae, Synechococcus to three carbon dioxide (CO2) conditions in different future climate contexts. It was found that when CO2 concentration increased to 850 ppm, the carbon allocation patterns did not have significantly changed compared to that under current CO2 concentration. In contrast, till the end of incubation, the extreme CO2 concentration of 1370 ppm led to significant decrease of 47.05% in the total organic carbon (TOC) concentration, with an increase of the concentration of extracellular DOC (DOCex) and a reduction of POC. Notably, the final proportion of DOCex increased to 44.32% from 22.66% of the DOC fraction. Our observed changes in carbon allocation of Synechococcus under extreme CO2 concentrations suggests a reduced contribution of Synechococcus to aquatic carbon sequestration via the biological carbon pump through POC sinking, with a larger proportion of microalgal carbon being directly allocated to the surface DOC pool in the form of potentially recalcitrant DOC. Our study has important implications for accurately evaluating the role of Synechococcus in aquatic carbon sequestration in the context of future climate change.