Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements
We report results of laboratory studies examining the effect of low levels of iron (Fe) availability on the intracellular Fe concentrations and specific growth rates in Southern Ocean diatoms (Fragilariopsis kerguelensis, Eucampia antarctica, Proboscia inermis, and Thalassiosira antarctica) and Phae...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.656.7030 2023-05-15T13:53:54+02:00 Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements Philip W. Boydc The Pennsylvania State University CiteSeerX Archives http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.656.7030 http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.656.7030 http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ text ftciteseerx 2016-01-08T16:38:56Z We report results of laboratory studies examining the effect of low levels of iron (Fe) availability on the intracellular Fe concentrations and specific growth rates in Southern Ocean diatoms (Fragilariopsis kerguelensis, Eucampia antarctica, Proboscia inermis, and Thalassiosira antarctica) and Phaeocystis antarctica. All species grew on Fe complexed to the siderophore desferrioxamine B (DFB). Concentrations of DFB up to 100-fold in excess of Fe were required to limit growth rates by $ 50%. Southern Ocean phytoplankton also grew on Fe complexed by $ 10-fold excess concentrations of the siderophores ferrichrome, enterobactin, or aerobactin, whereas the temperate coastal diatoms Thalassiosira weissflogii and Thalassiosira pseudonana did not. Intracellular Fe concentrations and Fe:C ratios of all Southern Ocean species were exceptionally low and decreased with decreasing Fe availability. However, large diatoms had significantly lower cell-volume–normalized Fe content and Fe:C ratios than Phaeocystis. Short-term Fe uptake and extracellular Fe(II) production measurements provided evidence that Phaeocystis possesses a reductive Fe transport pathway. Our findings demonstrate that the large-diatom Fe requirements are at least 2-fold lower than currently reported for oceanic algal species and suggest that bioreduction may enable resident phytoplankton to directly use Fe bound to strong organic ligands. Over the last 15 yr, numerous field and laboratory Text Antarc* Antarctica Southern Ocean Unknown Southern Ocean |
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We report results of laboratory studies examining the effect of low levels of iron (Fe) availability on the intracellular Fe concentrations and specific growth rates in Southern Ocean diatoms (Fragilariopsis kerguelensis, Eucampia antarctica, Proboscia inermis, and Thalassiosira antarctica) and Phaeocystis antarctica. All species grew on Fe complexed to the siderophore desferrioxamine B (DFB). Concentrations of DFB up to 100-fold in excess of Fe were required to limit growth rates by $ 50%. Southern Ocean phytoplankton also grew on Fe complexed by $ 10-fold excess concentrations of the siderophores ferrichrome, enterobactin, or aerobactin, whereas the temperate coastal diatoms Thalassiosira weissflogii and Thalassiosira pseudonana did not. Intracellular Fe concentrations and Fe:C ratios of all Southern Ocean species were exceptionally low and decreased with decreasing Fe availability. However, large diatoms had significantly lower cell-volume–normalized Fe content and Fe:C ratios than Phaeocystis. Short-term Fe uptake and extracellular Fe(II) production measurements provided evidence that Phaeocystis possesses a reductive Fe transport pathway. Our findings demonstrate that the large-diatom Fe requirements are at least 2-fold lower than currently reported for oceanic algal species and suggest that bioreduction may enable resident phytoplankton to directly use Fe bound to strong organic ligands. Over the last 15 yr, numerous field and laboratory |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Philip W. Boydc |
spellingShingle |
Philip W. Boydc Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
author_facet |
Philip W. Boydc |
author_sort |
Philip W. Boydc |
title |
Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
title_short |
Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
title_full |
Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
title_fullStr |
Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
title_full_unstemmed |
Adaptive strategies by Southern Ocean phytoplankton to lessen iron limitation: Uptake of organically complexed iron and reduced cellular iron requirements |
title_sort |
adaptive strategies by southern ocean phytoplankton to lessen iron limitation: uptake of organically complexed iron and reduced cellular iron requirements |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.656.7030 http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Antarc* Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctica Southern Ocean |
op_source |
http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.656.7030 http://ecite.utas.edu.au/X/C178C5946AC643938B7CD72114EAFAB0/ |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766259376313597952 |