Limitation of dimethylsulfoniopropionate synthesis at high irradiance in natural phytoplankton communities of the Tropical Atlantic
Limitation of dimethylsulfoniopropionate synthesis at high irradiance in natural phytoplankton communities of the Tropical Atlantic
复制标题
DOI：
10.1002/lno.10625
复制
发表时间：
2018-01-01
影响因子：
4.5
通讯作者：
Geider, Richard J.
中科院分区：
文献类型：
--
作者：
Archer, Stephen D.;Stefels, Jacqueline;Geider, Richard J.
通过了解是什么控制着二甲基磺基丙酸酯（DMSP）生产的季节性和区域性变化，将改善对二甲基硫醚海洋-大气通量的预测。为了探讨高水平的辐射，包括紫外线辐射（UVR）的影响，DMSP合成速率（μ DMSP）和无机碳固定（μ POC）的天然浮游植物群落，9个实验进行了在不同的位置在低营养盐，高光照环境的东北热带大西洋。通过测量无机C-13掺入DMSP和颗粒有机碳来确定μ DMSP和μ POC的速率。基于在一天中的离散时间间隔内的测量，建立了独特的μ DMSP与辐照度（P与E）的关系。比较与P与E的关系为亩POC，表明DMSP的光饱和发生在类似的辐照度亩POC和紧密耦合到碳固定的基础上的昼夜。在中午的光抑制加剧了暴露于紫外线辐射，造成额外的55-60%的抑制亩DMSP和亩POC在最高的光水平。此外，减少生产的DMSP响应紫外线诱导的光氧化胁迫，与增加的净合成的光保护叶黄素色素。总之，这些结果表明，DMSP生产的浮游植物在热带海洋中不受监管，在短期内的必要性，以控制日益增加的光氧化应激，在白天的辐照度增加。这项研究提供了新的见解，调节资源分配到这个地球化学重要的，多功能的相容溶质。
Predictions of the ocean-atmosphere flux of dimethyl sulfide will be improved by understanding what controls seasonal and regional variations in dimethylsulfoniopropionate (DMSP) production. To investigate the influence of high levels of irradiance including ultraviolet radiation (UVR), on DMSP synthesis rates (mu DMSP) and inorganic carbon fixation (mu POC) by natural phytoplankton communities, nine experiments were carried out at different locations in the low nutrient, high light environment of the northeastern Tropical Atlantic. Rates of mu DMSP and mu POC were determined by measuring the incorporation of inorganic C-13 into DMSP and particulate organic carbon. Based on measurements over discrete time intervals during the day, a unique mu DMSP vs. irradiance (P vs. E) relationship was established. Comparison is made with the P vs. E relationship for mu POC, indicating that light saturation of DMSP occurs at similar irradiance to mu POC and is closely coupled to carbon fixation on a diel basis. Photoinhibition during the middle of the day was exacerbated by exposure to UVR, causing an additional 55-60% inhibition of both mu DMSP and mu POC at the highest light levels. In addition, decreased production of DMSP in response to UVR-induced photoxidative stress, contrasted with the increased net synthesis of photoprotective xanthophyll pigments. Together these results indicate that DMSP production by phytoplankton in the tropical ocean is not regulated in the short term by the necessity to control increasing photooxidative stress as irradiance increases during the day. The study provides new insight into the regulation of resource allocation into this biogeochemically important, multi-functional compatible solute.