Acidification, not carbonation, is the major regulator of carbon fluxes in the coccolithophore E miliania huxleyi
| Autor: | Björn Rost, Sebastian D. Rokitta, Dorothee M. Kottmeier |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
Light 010504 meteorology & atmospheric sciences Physiology Coccolithophore Acclimatization Carbonates ocean acidification CO2‐concentrating mechanism Plant Science Photosynthesis life‐cycle stages 01 natural sciences Carbon Cycle Carbon cycle calcification chemistry.chemical_compound membrane‐inlet mass spectrometry Botany Dissolved organic carbon 14. Life underwater 0105 earth and related environmental sciences Emiliania huxleyi photosynthesis Full Paper biology pH Research 010604 marine biology & hydrobiology Haptophyta Ocean acidification Carbon Dioxide Hydrogen-Ion Concentration Full Papers biology.organism_classification Oxygen chemistry 13. Climate action Environmental chemistry Carbon dioxide |
| Zdroj: | The New Phytologist EPIC3New Phytologist, WILEY-BLACKWELL PUBLISHING, 211, pp. 126-137, ISSN: 0028-646X |
| ISSN: | 1469-8137 0028-646X |
| DOI: | 10.1111/nph.13885 |
| Popis: | A combined increase in seawater [CO2 ] and [H(+) ] was recently shown to induce a shift from photosynthetic HCO3 (-) to CO2 uptake in Emiliania huxleyi. This shift occurred within minutes, whereas acclimation to ocean acidification (OA) did not affect the carbon source. To identify the driver of this shift, we exposed low- and high-light acclimated E. huxleyi to a matrix of two levels of dissolved inorganic carbon (1400, 2800 μmol kg(-1) ) and pH (8.15, 7.85) and directly measured cellular O2 , CO2 and HCO3 (-) fluxes under these conditions. Exposure to increased [CO2 ] had little effect on the photosynthetic fluxes, whereas increased [H(+) ] led to a significant decline in HCO3 (-) uptake. Low-light acclimated cells overcompensated for the inhibition of HCO3 (-) uptake by increasing CO2 uptake. High-light acclimated cells, relying on higher proportions of HCO3 (-) uptake, could not increase CO2 uptake and photosynthetic O2 evolution consequently became carbon-limited. These regulations indicate that OA responses in photosynthesis are caused by [H(+) ] rather than by [CO2 ]. The impaired HCO3 (-) uptake also provides a mechanistic explanation for lowered calcification under OA. Moreover, it explains the OA-dependent decrease in photosynthesis observed in high-light grown phytoplankton. |
| Databáze: | OpenAIRE |
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