Sensitivity of Antarctic phytoplankton species to ocean acidification: Growth, carbon acquisition, and species interaction
Sensitivity of Antarctic phytoplankton species to ocean acidification: Growth, carbon acquisition, and species interaction
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DOI：
10.4319/lo.2013.58.3.0997
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发表时间：
2013-05
影响因子：
4.5
通讯作者：
S. Trimborn;Tina Brenneis;E. Sweet;B. Rost
中科院分区：
文献类型：
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作者：
S. Trimborn;Tina Brenneis;E. Sweet;B. Rost
尽管海洋酸化被认为在南大洋特别明显，但人们对二氧化碳依赖的生理过程和南极浮游植物关键物种的相互作用知之甚少。因此，我们研究了CO2分压（PCO 2）（16.2，39.5和101.3 Pa）对水华形成物种Chaetoceros debilis，Pseudo-nitzschia subcurvata，Fragilariopsis kerguelensis和Phaeocystis anarctica生长和光合碳获取的影响。使用膜入口质谱，光合O2释放和无机碳（Ci）通量作为CO2浓度的函数进行了测定。只有C.高PCO_2时，虚弱感增强。对碳浓缩机制（CCM）的分析揭示了非常有效的CCM的操作（即，高Ci亲和力），但在单个CCM组分的CO2依赖性调节方面存在物种特异性差异（即，CO2和吸收动力学，碳酸酐酶活性）。总CO2吸收率似乎随着细胞表面积与体积比的增加而增加。种间竞争实验表明，C.在不同PCO 2水平下，C. debilis和P. subcurvata的生长均受到CO2的刺激。在单特异性孵育中观察到，也存在P. subcurvata。不依赖于PCO 2，高初始细胞丰度的P. subcurvata导致C.虚弱为了更好地了解浮游植物群落的未来变化，需要确定CO2敏感的生理过程，但也必须考虑物种的相互作用，因为它们的相互作用决定了物种的成功。
Despite the fact that ocean acidification is considered to be especially pronounced in the Southern Ocean, little is known about CO2‐dependent physiological processes and the interactions of Antarctic phytoplankton key species. We therefore studied the effects of CO2 partial pressure (PCO2) (16.2, 39.5, and 101.3 Pa) on growth and photosynthetic carbon acquisition in the bloom‐forming species Chaetoceros debilis, Pseudo‐nitzschia subcurvata, Fragilariopsis kerguelensis, and Phaeocystis antarctica. Using membrane‐inlet mass spectrometry, photosynthetic O2 evolution and inorganic carbon (Ci) fluxes were determined as a function of CO2 concentration. Only the growth of C. debilis was enhanced under high PCO2. Analysis of the carbon concentrating mechanism (CCM) revealed the operation of very efficient CCMs (i.e., high Ci affinities) in all species, but there were species‐specific differences in CO2‐dependent regulation of individual CCM components (i.e., CO2 and uptake kinetics, carbonic anhydrase activities). Gross CO2 uptake rates appear to increase with the cell surface area to volume ratios. Species competition experiments with C. debilis and P. subcurvata under different PCO2 levels confirmed the CO2‐stimulated growth of C. debilis observed in monospecific incubations, also in the presence of P. subcurvata. Independent of PCO2, high initial cell abundances of P. subcurvata led to reduced growth rates of C. debilis. For a better understanding of future changes in phytoplankton communities, CO2‐sensitive physiological processes need to be identified, but also species interactions must be taken into account because their interplay determines the success of a species.