Data

Photosynthetic adaptation to low iron, light, and temperature in Southern Ocean phytoplankton

University of Tasmania, Australia
Strzepek, Robert, Dr
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/6fbeb554-352b-4b79-b986-debfff6e3a01&rft.title=Photosynthetic adaptation to low iron, light, and temperature in Southern Ocean phytoplankton&rft.identifier=https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/6fbeb554-352b-4b79-b986-debfff6e3a01&rft.description=Phytoplankton productivity in the polar Southern Ocean (SO) plays an important role in the transfer of carbon from the atmosphere to the ocean’s interior, a process called the biological carbon pump, which helps regulate global climate. SO productivity in turn is limited by low iron, light, and temperature, which restrict the ef- ficiency of the carbon pump. Iron and light can colimit productivity due to the high iron content of the photosynthetic photosystems and the need for increased photosystems for low-light acclimation in many phytoplankton. Here we show that SO phytoplankton have evolved critical adaptations to enhance photosynthetic rates under the joint constraints of low iron, light, and temperature. Under growth-limiting iron and light levels, three SO species had up to sixfold higher photosynthetic rates per photosystem II and similar or higher rates per mol of photosynthetic iron than tem- perate species, despite their lower growth temperature (3 vs. 18 °C) and light intensity (30 vs. 40 μmol quanta·m2·s−1), which should have decreased photosynthetic rates. These unexpectedly high rates in the SO species are partly explained by their unusually large photosynthetic antennae, which are among the largest ever recorded in marine phytoplankton. Large antennae are disadvan- tageous at low light intensities because they increase excitation energy loss as heat, but this loss may be mitigated by the low SO temperatures. Such adaptations point to higher SO production rates than environmental conditions should otherwise permit, with implications for regional ecology and biogeochemistry.Maintenance and Update Frequency: notPlannedStatement: Southern Ocean phytoplankton isolates were grown under trace metal clean conditions in a low temperature incubator under low and high iron concentrations at sub saturating continuous light. The cultures were sampled for growth rates, intracellular iron and carbon concentrations, and photosynthetic rates and composition.&rft.creator=Strzepek, Robert, Dr &rft.date=2019&rft.coverage=westlimit=147.197753906; southlimit=-42.9849030764; eastlimit=147.505371094; northlimit=-42.7931625259&rft.coverage=westlimit=147.197753906; southlimit=-42.9849030764; eastlimit=147.505371094; northlimit=-42.7931625259&rft_rights=The data described in this record are the intellectual property of the University of Tasmania through the Institute for Marine and Antarctic Studies.&rft_rights= http://creativecommons.org/licenses/by/4.0/&rft_rights=http://i.creativecommons.org/l/by/4.0/88x31.png&rft_rights=WWW:LINK-1.0-http--related&rft_rights=License Graphic&rft_rights=Creative Commons Attribution 4.0 International License&rft_rights=http://creativecommons.org/international/&rft_rights=WWW:LINK-1.0-http--related&rft_rights=WWW:LINK-1.0-http--related&rft_rights=License Text&rft_rights=The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).&rft_rights=Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0&rft_subject=biota&rft_subject=iron&rft_subject=light&rft_subject=temperature&rft_subject=Eucampia antarctica&rft_subject=Proboscia inermis&rft_subject=Phaeocystis antarctica&rft_subject=Thalassiosira oceanica&rft_subject=Thalassiosira weissflogii&rft_subject=EARTH SCIENCE | BIOSPHERE | ECOSYSTEMS | AQUATIC ECOSYSTEMS | PLANKTON | PHYTOPLANKTON&rft_subject=EARTH SCIENCE | BIOSPHERE | ECOSYSTEMS | MARINE ECOSYSTEMS&rft_subject=EARTH SCIENCE | BIOSPHERE | ECOLOGICAL DYNAMICS | ECOSYSTEM FUNCTIONS | PHOTOSYNTHESIS&rft.type=dataset&rft.language=English Access the data

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Brief description

Phytoplankton productivity in the polar Southern Ocean (SO) plays an important role in the transfer of carbon from the atmosphere to the ocean’s interior, a process called the biological carbon pump, which helps regulate global climate. SO productivity in turn is limited by low iron, light, and temperature, which restrict the ef- ficiency of the carbon pump. Iron and light can colimit productivity due to the high iron content of the photosynthetic photosystems and the need for increased photosystems for low-light acclimation in many phytoplankton. Here we show that SO phytoplankton have evolved critical adaptations to enhance photosynthetic rates under the joint constraints of low iron, light, and temperature. Under growth-limiting iron and light levels, three SO species had up to sixfold higher photosynthetic rates per photosystem II and similar or higher rates per mol of photosynthetic iron than tem- perate species, despite their lower growth temperature (3 vs. 18 °C) and light intensity (30 vs. 40 μmol quanta·m2·s−1), which should have decreased photosynthetic rates. These unexpectedly high rates in the SO species are partly explained by their unusually large photosynthetic antennae, which are among the largest ever recorded in marine phytoplankton. Large antennae are disadvan- tageous at low light intensities because they increase excitation energy loss as heat, but this loss may be mitigated by the low SO temperatures. Such adaptations point to higher SO production rates than environmental conditions should otherwise permit, with implications for regional ecology and biogeochemistry.

Lineage

Maintenance and Update Frequency: notPlanned
Statement: Southern Ocean phytoplankton isolates were grown under trace metal clean conditions in a low temperature incubator under low and high iron concentrations at sub saturating continuous light. The cultures were sampled for growth rates, intracellular iron and carbon concentrations, and photosynthetic rates and composition.

Notes

Credit
Marsden Fund of New Zealand
Credit
Ministry of Science and Innovation New Zealand

Created: 2019-08-09

Data time period: 2017-01-01 to 2019-01-23

This dataset is part of a larger collection

Click to explore relationships graph

147.50537,-42.79316 147.50537,-42.9849 147.19775,-42.9849 147.19775,-42.79316 147.50537,-42.79316

147.3515625,-42.88903280115

text: westlimit=147.197753906; southlimit=-42.9849030764; eastlimit=147.505371094; northlimit=-42.7931625259

Other Information
(DATA ACCESS - contained within supplementary materials [direct download])

uri : https://data.imas.utas.edu.au/attachments/6fbeb554-352b-4b79-b986-debfff6e3a01/1810886116.full.pdf

(PUBLICATION - Photosynthetic adaptation low iron, light, and temperature in Southern Ocean phytoplankton [direct download])

uri : https://data.imas.utas.edu.au/attachments/6fbeb554-352b-4b79-b986-debfff6e3a01/pnas.1810886116.sapp.pdf

Identifiers
  • global : 6fbeb554-352b-4b79-b986-debfff6e3a01