The nature of the CO2 -concentrating mechanisms in a marine diatom, Thalassiosira pseudonana
© 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 209(2016), 4 vom: 15. März, Seite 1417-27 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2016
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Bicarbonate use CO2 Thalassiosira pseudonana carbon dioxide-concentrating mechanism (CCM) diatom photosynthesis Bicarbonates Carbon Dioxide mehr... |
| Zusammenfassung: | © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust. Diatoms are widespread in aquatic ecosystems where they may be limited by the supply of inorganic carbon. Their carbon dioxide-concentrating mechanisms (CCMs) involving transporters and carbonic anhydrases (CAs) are well known, but the contribution of a biochemical CCM involving C4 metabolism is contentious. The CCM(s) present in the marine-centric diatom, Thalassiosira pseudonana, were studied in cells exposed to high or low concentrations of CO2 , using a range of approaches. At low CO2 , cells possessed a CCM based on active uptake of CO2 (70% contribution) and bicarbonate, while at high CO2 , cells were restricted to CO2 . CA was highly and rapidly activated on transfer to low CO2 and played a key role because inhibition of external CA produced uptake kinetics similar to cells grown at high CO2 . The activities of phosphoenolpyruvate (PEP) carboxylase (PEPC) and the PEP-regenerating enzyme, pyruvate phosphate dikinase (PPDK), were lower in cells grown at low than at high CO2 . The ratios of PEPC and PPDK to ribulose bisphosphate carboxylase were substantially lower than 1, even at low CO2 . Our data suggest that the kinetic properties of this species results from a biophysical CCM and not from C4 type metabolism |
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| Beschreibung: | Date Completed 19.12.2016 Date Revised 09.04.2022 published: Print-Electronic ErratumIn: New Phytol. 2016 Apr;210(2):762. - PMID 27000957 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13728 |