Dissecting the impact of CO2and pH on the mechanisms of photosynthesis and calcification in the coccolithophoreEmiliania huxleyi
Bach, Lennart T., Mackinder, Luke, Schulz, Kai G., Wheeler, Glen, Schroeder, Declan C., Brownlee, Colin and Riebesell, Ulf (2013) Dissecting the impact of CO2and pH on the mechanisms of photosynthesis and calcification in the coccolithophoreEmiliania huxleyi New Phytologist, 199 (1). pp. 121-134. DOI 10.1111/nph.12225.
nph12225.pdf - Published Version
Download (913Kb) | Preview
Coccolithophores are important calcifying phytoplankton predicted to be impacted by changes in ocean carbonate chemistry caused by the absorption of anthropogenic CO2. However, it is difficult to disentangle the effects of the simultaneously changing carbonate system parameters (CO2, bicarbonate, carbonate and protons) on the physiological responses to elevated CO2.
Here, we adopted a multifactorial approach at constant pH or CO2 whilst varying dissolved inorganic carbon (DIC) to determine physiological and transcriptional responses to individual carbonate system parameters.
We show that Emiliania huxleyi is sensitive to low CO2 (growth and photosynthesis) and low bicarbonate (calcification) as well as low pH beyond a limited tolerance range, but is much less sensitive to elevated CO2 and bicarbonate. Multiple up-regulated genes at low DIC bear the hallmarks of a carbon-concentrating mechanism (CCM) that is responsive to CO2 and bicarbonate but not to pH.
Emiliania huxleyi appears to have evolved mechanisms to respond to limiting rather than elevated CO2. Calcification does not function as a CCM, but is inhibited at low DIC to allow the redistribution of DIC from calcification to photosynthesis. The presented data provides a significant step in understanding how E. huxleyi will respond to changing carbonate chemistry at a cellular level.
|Keywords:||calcification; carbon-concentrating mechanisms (CCMs); climate change; coccolithophores; Emiliania huxleyi; ocean acidification; phytoplankton|
|Research affiliation:||OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BI Biological Oceanography|
|Date Deposited:||03 Apr 2013 09:38|
|Last Modified:||16 Feb 2017 07:47|
Actions (login required)
Document DownloadsMore statistics for this item...
Copyright 2013 | GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel | All rights reserved
Questions, comments and suggestions regarding the GEOMAR repository are welcomed
at firstname.lastname@example.org !