Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms
Summary High‐latitude oceans are areas of high primary production despite temperatures that are often well below the thermal optima of enzymes, including the key C alvin C ycle enzyme, R ibulose 1,5 bisphosphate carboxylase oxygenase ( R ubisco). We measured carbon fixation rates, protein content an...
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crwiley:10.1111/nph.13021 2024-09-15T17:43:00+00:00 Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms Young, Jodi N. Goldman, Johanna A. L. Kranz, Sven A. Tortell, Philippe D. Morel, Francois M. M. US National Science Foundation Natural Science and Engineering Research Council of Canada 2014 http://dx.doi.org/10.1111/nph.13021 http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fnph.13021 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fnph.13021 https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.13021 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/nph.13021 https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.13021 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor http://doi.wiley.com/10.1002/tdm_license_1.1 New Phytologist volume 205, issue 1, page 172-181 ISSN 0028-646X 1469-8137 journal-article 2014 crwiley https://doi.org/10.1111/nph.13021 2024-08-20T04:18:10Z Summary High‐latitude oceans are areas of high primary production despite temperatures that are often well below the thermal optima of enzymes, including the key C alvin C ycle enzyme, R ibulose 1,5 bisphosphate carboxylase oxygenase ( R ubisco). We measured carbon fixation rates, protein content and R ubisco abundance and catalytic rates during an intense diatom bloom in the W estern A ntarctic P eninsula ( WAP ) and in laboratory cultures of a psychrophilic diatom ( F ragilariopsis cylindrus ). At −1°C, the R ubisco turnover rate, k cat c , was 0.4 C s −1 per site and the half saturation constant for CO 2 was 15 μM (vs c . 3 C s −1 per site and 50 μM at 20°C). To achieve high carboxylation rates, psychrophilic diatoms increased R ubisco abundance to c . 8% of biomass (vs c . 0.6% at 20°C), along with their total protein content, resulting in a low carbon : nitrogen ratio of c . 5. In psychrophilic diatoms, R ubisco must be almost fully active and near CO 2 saturation to achieve carbon fixation rates observed in the WAP . Correspondingly, total protein concentrations were close to the highest ever measured in phytoplankton and likely near the maximum possible. We hypothesize that this high protein concentration, like that of R ubisco, is necessitated by slow enzyme rates, and that carbon fixation rates in the WAP are near a theoretical maximum. Article in Journal/Newspaper Antarc* Antarctic Wiley Online Library New Phytologist 205 1 172 181 |
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Wiley Online Library |
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English |
description |
Summary High‐latitude oceans are areas of high primary production despite temperatures that are often well below the thermal optima of enzymes, including the key C alvin C ycle enzyme, R ibulose 1,5 bisphosphate carboxylase oxygenase ( R ubisco). We measured carbon fixation rates, protein content and R ubisco abundance and catalytic rates during an intense diatom bloom in the W estern A ntarctic P eninsula ( WAP ) and in laboratory cultures of a psychrophilic diatom ( F ragilariopsis cylindrus ). At −1°C, the R ubisco turnover rate, k cat c , was 0.4 C s −1 per site and the half saturation constant for CO 2 was 15 μM (vs c . 3 C s −1 per site and 50 μM at 20°C). To achieve high carboxylation rates, psychrophilic diatoms increased R ubisco abundance to c . 8% of biomass (vs c . 0.6% at 20°C), along with their total protein content, resulting in a low carbon : nitrogen ratio of c . 5. In psychrophilic diatoms, R ubisco must be almost fully active and near CO 2 saturation to achieve carbon fixation rates observed in the WAP . Correspondingly, total protein concentrations were close to the highest ever measured in phytoplankton and likely near the maximum possible. We hypothesize that this high protein concentration, like that of R ubisco, is necessitated by slow enzyme rates, and that carbon fixation rates in the WAP are near a theoretical maximum. |
author2 |
US National Science Foundation Natural Science and Engineering Research Council of Canada |
format |
Article in Journal/Newspaper |
author |
Young, Jodi N. Goldman, Johanna A. L. Kranz, Sven A. Tortell, Philippe D. Morel, Francois M. M. |
spellingShingle |
Young, Jodi N. Goldman, Johanna A. L. Kranz, Sven A. Tortell, Philippe D. Morel, Francois M. M. Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
author_facet |
Young, Jodi N. Goldman, Johanna A. L. Kranz, Sven A. Tortell, Philippe D. Morel, Francois M. M. |
author_sort |
Young, Jodi N. |
title |
Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
title_short |
Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
title_full |
Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
title_fullStr |
Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
title_full_unstemmed |
Slow carboxylation of Rubisco constrains the rate of carbon fixation during Antarctic phytoplankton blooms |
title_sort |
slow carboxylation of rubisco constrains the rate of carbon fixation during antarctic phytoplankton blooms |
publisher |
Wiley |
publishDate |
2014 |
url |
http://dx.doi.org/10.1111/nph.13021 http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fnph.13021 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fnph.13021 https://onlinelibrary.wiley.com/doi/pdf/10.1111/nph.13021 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/nph.13021 https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.13021 |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
New Phytologist volume 205, issue 1, page 172-181 ISSN 0028-646X 1469-8137 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor http://doi.wiley.com/10.1002/tdm_license_1.1 |
op_doi |
https://doi.org/10.1111/nph.13021 |
container_title |
New Phytologist |
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205 |
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1 |
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172 |
op_container_end_page |
181 |
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1810489832226422784 |