Microelectrode characterization of coral daytime interior pH and carbonate chemistry.
Microelectrode characterization of coral daytime interior pH and carbonate chemistry.
复制标题
DOI：
10.1038/ncomms11144
复制
发表时间：
2016-04-04
影响因子：
16.6
通讯作者：
Wang Y
中科院分区：
文献类型：
--
作者：
Cai WJ;Ma Y;Hopkinson BM;Grottoli AG;Warner ME;Ding Q;Hu X;Yuan X;Schoepf V;Xu H;Han C;Melman TF;Hoadley KD;Pettay DT;Matsui Y;Baumann JH;Levas S;Ying Y;Wang Y
可靠地预测珊瑚钙化如何对海洋酸化和变暖作出反应取决于我们对珊瑚钙化机制的理解。然而，珊瑚体内溶解无机碳（DIC）的浓度和形态仍不清楚，因为只测量了pH值，而用于确定碳酸盐化学的必要的第二个参数一直缺失。在此，我们报告了在光照期间珊瑚体内首次进行的碳酸根离子浓度（[CO₃²⁻]）以及pH值的测量结果。我们观察到从胃腔到钙化液中[CO₃²⁻]和pH值急剧上升，证实了质子（H⁺）泵机制的存在。我们还表明，珊瑚可以通过提高pH值同时保持较低的[DIC]，在钙化液中实现较高的文石饱和度（Ωarag）。与高[DIC]的情况相比，这种机制可能需要较少的H⁺泵送和能量来上调pH值，因此可能使珊瑚对与气候变化相关的压力源更具抵抗力。
预测珊瑚对海洋酸化的反应取决于我们对其内部碳酸盐化学的理解。在这里，作者利用微电极表明，珊瑚提高其钙化液中的pH值和碳酸根离子浓度，但保持总溶解无机碳较低。
Reliably predicting how coral calcification may respond to ocean acidification and warming depends on our understanding of coral calcification mechanisms. However, the concentration and speciation of dissolved inorganic carbon (DIC) inside corals remain unclear, as only pH has been measured while a necessary second parameter to constrain carbonate chemistry has been missing. Here we report the first carbonate ion concentration ([CO32−]) measurements together with pH inside corals during the light period. We observe sharp increases in [CO32−] and pH from the gastric cavity to the calcifying fluid, confirming the existence of a proton (H+) pumping mechanism. We also show that corals can achieve a high aragonite saturation state (Ωarag) in the calcifying fluid by elevating pH while at the same time keeping [DIC] low. Such a mechanism may require less H+-pumping and energy for upregulating pH compared with the high [DIC] scenario and thus may allow corals to be more resistant to climate change related stressors. Predicting coral response to ocean acidification is dependent on our understanding of their internal carbonate chemistry. Here, using microelectrodes, the authors show that corals elevate pH and carbonate ion concentration in their calcifying fluid, but keep total dissolved inorganic carbon low.