_version_ 1867170987797118976
author Müller, Marius N
author_facet Müller, Marius N
collection Datos científicos de ciencias marinas y ambientales
contents Marine phytoplankton has developed the remarkable ability to tightly regulate the concentration of free calcium ions in the intracellular cytosol at a level of ~ 0.1 µmol /l in the presence of seawater Ca2+ concentrations of 10 mmol/1. The low cytosolic calcium ion concentration is of utmost importance for proper cell signalling function. While the regulatory mechanisms responsible for the tight control of intracellular Ca2+ concentration are not completely understood, phytoplankton taxonomic groups appear to have evolved different strategies, which may affect their ability to cope with changes in seawater Ca2+ concentrations in their environment on geological time scales. For example, the Cretaceous (145 to 66 Ma ago), an era known for the high abundance of coccolithophores and the production of enormous calcium carbonate deposits, exhibited seawater calcium concentrations up to four times present-day levels. We show that calcifying coccolithophore species (Emiliania huxleyi, Gephyrocapsa oceanica and Coccolithus braarudii) are able to maintain their relative fitness (in terms of growth rate and photosynthesis) at simulated Cretaceous seawater calcium concentrations, whereas these rates are severely reduced under these conditions in some non-calcareous phytoplankton species (Chaetoceros sp., Ceratoneis closterium and Heterosigma akashiwo). Most notably, this also applies to a non-calcifying strain of E. huxleyi which displays a calcium-sensitivity similar to the non-calcareous species. We hypothesize that the process of calcification in coccolithophores provides an efficient mechanism to alleviate cellular calcium poisoning and thereby offered a potential key evolutionary advantage, responsible for the proliferation of coccolithophores during times of high seawater calcium concentrations. The exact function of calcification and the reason behind the highly-ornate physical structures of coccoliths remain elusive.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_854719
institution PANGAEA
language en
publishDate 2015
publisher PANGAEA
record_format pangaea
spellingShingle Phytoplankton calcification as an effective mechanism to alleviate cellular calcium poisoning
Müller, Marius N
Alkalinity, total; Alkalinity, total, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Calcium; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon, inorganic, particulate, per cell; Carbon, inorganic, particulate, production per cell; Carbon, organic, particulate, per cell; Carbon, organic, particulate, production per cell; Carbon, organic, particulate, standard deviation; Growth rate; Growth rate, standard deviation; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, total scale; Photosynthetic competence; Photosynthetic efficiency, standard deviation; Species; Standard deviation
Marine phytoplankton has developed the remarkable ability to tightly regulate the concentration of free calcium ions in the intracellular cytosol at a level of ~ 0.1 µmol /l in the presence of seawater Ca2+ concentrations of 10 mmol/1. The low cytosolic calcium ion concentration is of utmost importance for proper cell signalling function. While the regulatory mechanisms responsible for the tight control of intracellular Ca2+ concentration are not completely understood, phytoplankton taxonomic groups appear to have evolved different strategies, which may affect their ability to cope with changes in seawater Ca2+ concentrations in their environment on geological time scales. For example, the Cretaceous (145 to 66 Ma ago), an era known for the high abundance of coccolithophores and the production of enormous calcium carbonate deposits, exhibited seawater calcium concentrations up to four times present-day levels. We show that calcifying coccolithophore species (Emiliania huxleyi, Gephyrocapsa oceanica and Coccolithus braarudii) are able to maintain their relative fitness (in terms of growth rate and photosynthesis) at simulated Cretaceous seawater calcium concentrations, whereas these rates are severely reduced under these conditions in some non-calcareous phytoplankton species (Chaetoceros sp., Ceratoneis closterium and Heterosigma akashiwo). Most notably, this also applies to a non-calcifying strain of E. huxleyi which displays a calcium-sensitivity similar to the non-calcareous species. We hypothesize that the process of calcification in coccolithophores provides an efficient mechanism to alleviate cellular calcium poisoning and thereby offered a potential key evolutionary advantage, responsible for the proliferation of coccolithophores during times of high seawater calcium concentrations. The exact function of calcification and the reason behind the highly-ornate physical structures of coccoliths remain elusive.
title Phytoplankton calcification as an effective mechanism to alleviate cellular calcium poisoning
topic Alkalinity, total; Alkalinity, total, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Calcium; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon, inorganic, particulate, per cell; Carbon, inorganic, particulate, production per cell; Carbon, organic, particulate, per cell; Carbon, organic, particulate, production per cell; Carbon, organic, particulate, standard deviation; Growth rate; Growth rate, standard deviation; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, total scale; Photosynthetic competence; Photosynthetic efficiency, standard deviation; Species; Standard deviation
url https://doi.org/10.1594/PANGAEA.854719