Strong shift from HCO3 (-) to CO 2 uptake in Emiliania huxleyi with acidification: new approach unravels acclimation versus short-term pH effects.
Strong shift from HCO3 (-) to CO 2 uptake in Emiliania huxleyi with acidification: new approach unravels acclimation versus short-term pH effects.
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DOI：
10.1007/s11120-014-9984-9
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发表时间：
2014-09
影响因子：
3.7
通讯作者：
Rost, Bjoern
中科院分区：
文献类型：
--
作者：
Kottmeier, Dorothee M.;Rokitta, Sebastian D.;Tortell, Philippe D.;Rost, Bjoern
关键词：
通过测量不同pCO 2水平（380和950 μatm）下的生长、元素组成和生产率，研究了海洋酸化对Emiliania huxleyi菌株RCC 1216（钙化，二倍体生命周期阶段）和RCC 1217（非钙化，单倍体生命周期阶段）的影响。在这些不同驯化的细胞中，通过14 C不平衡测定评估光合作用碳源，在生态相关pH值范围内（7.9-8.7）进行。与以前的研究一致，我们观察到减少钙化和高pCO 2刺激二倍体细胞的生物量生产，但没有CO2依赖性的变化，单倍体细胞的生物量生产。在这两个生命周期阶段，CO2和HCO 3 −吸收的相对贡献强烈依赖于测定pH值。在pH值≤ 8.1时，细胞优先使用CO2（≥ 90%CO2），而在pH值≥ 8.3时，细胞逐渐增加HCO 3 −摄取分数（二倍体细胞中pH 8.7时约45%CO2;单倍体细胞中pH 8.5时约55%CO2）。与测定pH值的短期影响相反，pCO 2驯化历史对碳吸收行为无显著影响。数值敏感性研究证实，如果模型参数（例如，pH、温度）保持在典型的测量不确定度范围内。我们的研究结果表明，E。huxleyi快速调整碳获取外部碳供应和/或pH值，并提供了一个解释的矛盾观察高CO2的敏感性，尽管在以前的研究中看到的HCO 3 −使用明显高。本文的在线版本（doi：10.1007/s11120-014-9984-9）包含补充材料，可供授权用户使用。
Effects of ocean acidification on Emiliania huxleyi strain RCC 1216 (calcifying, diploid life-cycle stage) and RCC 1217 (non-calcifying, haploid life-cycle stage) were investigated by measuring growth, elemental composition, and production rates under different pCO2 levels (380 and 950 μatm). In these differently acclimated cells, the photosynthetic carbon source was assessed by a 14C disequilibrium assay, conducted over a range of ecologically relevant pH values (7.9–8.7). In agreement with previous studies, we observed decreased calcification and stimulated biomass production in diploid cells under high pCO2, but no CO2-dependent changes in biomass production for haploid cells. In both life-cycle stages, the relative contributions of CO2 and HCO3 − uptake depended strongly on the assay pH. At pH values ≤ 8.1, cells preferentially used CO2 (≥ 90 % CO2), whereas at pH values ≥ 8.3, cells progressively increased the fraction of HCO3 − uptake (~45 % CO2 at pH 8.7 in diploid cells; ~55 % CO2 at pH 8.5 in haploid cells). In contrast to the short-term effect of the assay pH, the pCO2 acclimation history had no significant effect on the carbon uptake behavior. A numerical sensitivity study confirmed that the pH-modification in the 14C disequilibrium method yields reliable results, provided that model parameters (e.g., pH, temperature) are kept within typical measurement uncertainties. Our results demonstrate a high plasticity of E. huxleyi to rapidly adjust carbon acquisition to the external carbon supply and/or pH, and provide an explanation for the paradoxical observation of high CO2 sensitivity despite the apparently high HCO3 − usage seen in previous studies. The online version of this article (doi:10.1007/s11120-014-9984-9) contains supplementary material, which is available to authorized users.
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DOI：
10.1016/0198-0149(81)90121-7
发表时间：
1981-01-01
期刊：
DEEP-SEA RESEARCH PART A-OCEANOGRAPHIC RESEARCH PAPERS
影响因子：
--
作者：
DICKSON, AG
通讯作者：
DICKSON, AG
影响因子：
2.8
作者：
GUILLARD, RR;RYTHER, JH
通讯作者：
RYTHER, JH
影响因子：
5.2
作者：
Cassar, N;Laws, EA;Popp, BN
通讯作者：
Popp, BN
影响因子：
3.7
作者：
Badger, M
通讯作者：
Badger, M
影响因子：
2.6
作者：
DICKSON, AG
通讯作者：
DICKSON, AG