Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity
Antarctic algae are exposed to prolonged periods of extreme darkness due to polar night, and coverage by ice and snow can extend such dark conditions to up to 10 months. A major group of microalgae in benthic habitats of Antarctica are diatoms, which are key primary producers in these regions. Howev...
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Online Access: | http://dx.doi.org/10.3389/fpls.2024.1326375 https://www.frontiersin.org/articles/10.3389/fpls.2024.1326375/full |
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crfrontiers:10.3389/fpls.2024.1326375 2024-04-21T07:50:06+00:00 Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity Handy, Jacob Juchem, Desirée Wang, Qian Schimani, Katherina Skibbe, Oliver Zimmermann, Jonas Karsten, Ulf Herburger, Klaus 2024 http://dx.doi.org/10.3389/fpls.2024.1326375 https://www.frontiersin.org/articles/10.3389/fpls.2024.1326375/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Plant Science volume 15 ISSN 1664-462X Plant Science journal-article 2024 crfrontiers https://doi.org/10.3389/fpls.2024.1326375 2024-03-26T08:35:13Z Antarctic algae are exposed to prolonged periods of extreme darkness due to polar night, and coverage by ice and snow can extend such dark conditions to up to 10 months. A major group of microalgae in benthic habitats of Antarctica are diatoms, which are key primary producers in these regions. However, the effects of extremely prolonged dark exposure on their photosynthesis, cellular ultrastructure, and cell integrity remain unknown. Here we show that five strains of Antarctic benthic diatoms exhibit an active photosynthetic apparatus despite 10 months of dark-exposure. This was shown by a steady effective quantum yield of photosystem II (Y[II]) upon light exposure for up to 2.5 months, suggesting that Antarctic diatoms do not rely on metabolically inactive resting cells to survive prolonged darkness. While limnic strains performed better than their marine counterparts, Y(II) recovery to values commonly observed in diatoms occurred after 4-5 months of light exposure in all strains, suggesting long recovering times. Dark exposure for 10 months dramatically reduced the chloroplast ultrastructure, thylakoid stacking, and led to a higher proportion of cells with compromised membranes than in light-adapted cells. However, photosynthetic oxygen production was readily measurable after darkness and strong photoinhibition only occurred at high light levels (>800 µmol photons m -2 s -1 ). Our data suggest that Antarctic benthic diatoms are well adapted to long dark periods. However, prolonged darkness for several months followed by only few months of light and another dark period may prevent them to regain their full photosynthetic potential due to long recovery times, which might compromise long-term population survival. Article in Journal/Newspaper Antarc* Antarctic Antarctica polar night Frontiers (Publisher) Frontiers in Plant Science 15 |
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Plant Science |
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Plant Science Handy, Jacob Juchem, Desirée Wang, Qian Schimani, Katherina Skibbe, Oliver Zimmermann, Jonas Karsten, Ulf Herburger, Klaus Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
topic_facet |
Plant Science |
description |
Antarctic algae are exposed to prolonged periods of extreme darkness due to polar night, and coverage by ice and snow can extend such dark conditions to up to 10 months. A major group of microalgae in benthic habitats of Antarctica are diatoms, which are key primary producers in these regions. However, the effects of extremely prolonged dark exposure on their photosynthesis, cellular ultrastructure, and cell integrity remain unknown. Here we show that five strains of Antarctic benthic diatoms exhibit an active photosynthetic apparatus despite 10 months of dark-exposure. This was shown by a steady effective quantum yield of photosystem II (Y[II]) upon light exposure for up to 2.5 months, suggesting that Antarctic diatoms do not rely on metabolically inactive resting cells to survive prolonged darkness. While limnic strains performed better than their marine counterparts, Y(II) recovery to values commonly observed in diatoms occurred after 4-5 months of light exposure in all strains, suggesting long recovering times. Dark exposure for 10 months dramatically reduced the chloroplast ultrastructure, thylakoid stacking, and led to a higher proportion of cells with compromised membranes than in light-adapted cells. However, photosynthetic oxygen production was readily measurable after darkness and strong photoinhibition only occurred at high light levels (>800 µmol photons m -2 s -1 ). Our data suggest that Antarctic benthic diatoms are well adapted to long dark periods. However, prolonged darkness for several months followed by only few months of light and another dark period may prevent them to regain their full photosynthetic potential due to long recovery times, which might compromise long-term population survival. |
format |
Article in Journal/Newspaper |
author |
Handy, Jacob Juchem, Desirée Wang, Qian Schimani, Katherina Skibbe, Oliver Zimmermann, Jonas Karsten, Ulf Herburger, Klaus |
author_facet |
Handy, Jacob Juchem, Desirée Wang, Qian Schimani, Katherina Skibbe, Oliver Zimmermann, Jonas Karsten, Ulf Herburger, Klaus |
author_sort |
Handy, Jacob |
title |
Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
title_short |
Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
title_full |
Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
title_fullStr |
Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
title_full_unstemmed |
Antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
title_sort |
antarctic benthic diatoms after 10 months of dark exposure: consequences for photosynthesis and cellular integrity |
publisher |
Frontiers Media SA |
publishDate |
2024 |
url |
http://dx.doi.org/10.3389/fpls.2024.1326375 https://www.frontiersin.org/articles/10.3389/fpls.2024.1326375/full |
genre |
Antarc* Antarctic Antarctica polar night |
genre_facet |
Antarc* Antarctic Antarctica polar night |
op_source |
Frontiers in Plant Science volume 15 ISSN 1664-462X |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fpls.2024.1326375 |
container_title |
Frontiers in Plant Science |
container_volume |
15 |
_version_ |
1796933957713920000 |