Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms
The availability of dissolved nutrients such as nitrate under extreme low temperatures is a strong determinant in the development and growth of ice diatoms. Consequently we investigated regulation of photosynthesis in a mixed culture of three diatom species, which grew in chemostats at -1 °C, 15 µmo...
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2002
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ftuniveastangl:oai:ueaeprints.uea.ac.uk:33143 2023-06-06T11:43:47+02:00 Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms Mock, Thomas Kroon, Bernd M. A. 2002 https://ueaeprints.uea.ac.uk/id/eprint/33143/ https://doi.org/10.1016/S0031-9422(02)00216-9 unknown Mock, Thomas and Kroon, Bernd M. A. (2002) Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms. Phytochemistry, 61 (1). pp. 41-51. ISSN 1873-3700 doi:10.1016/S0031-9422(02)00216-9 Article PeerReviewed 2002 ftuniveastangl https://doi.org/10.1016/S0031-9422(02)00216-9 2023-04-13T22:31:36Z The availability of dissolved nutrients such as nitrate under extreme low temperatures is a strong determinant in the development and growth of ice diatoms. Consequently we investigated regulation of photosynthesis in a mixed culture of three diatom species, which grew in chemostats at -1 °C, 15 µmol photons m-2 s-1 under N-limitation. When nitrogen is limiting, pigment-protein complexes are one of the most affected structures under low-light conditions. The loss of integral polar thylakoid components destabilized the bilayer structure of the membrane with consequences for lipid composition and the degree of fatty acid desaturation. N-Limitation caused a decrease in monogalactosydiacylglycerol (MGDG) and a simultaneous increase in bilayer forming digalactosyldiacylglycerol (DGDG). Their ratio MGDG:DGDG decreased from 3.4±0.1 to 1.1±0.4, while 20:5 n-3 fatty acids of chloroplast related phospholipid classes such as phosphatidylglycerol (PG) increased under N-limitation. These data reveal that lipids are important components, required to sustain membrane structure under a deficiency of integral membrane bound proteins and pigments. Nonetheless, energy conversion at photosystem II is still affected by N-limitation despite this structural regulation. Photosynthetic quantum yield (Fv/Fm) and electron transport rates decreased under N-limitation caused by an increasing amount of electron acceptors (second stable electron acceptor=QB) which had slower reoxidation kinetics. The energy surplus under these conditions is stored in triacylglycerols, the main energy sink in Antarctic sea ice diatoms under N-limitation. Article in Journal/Newspaper Antarc* Antarctic Sea ice University of East Anglia: UEA Digital Repository Antarctic Phytochemistry 61 1 41 51 |
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Open Polar |
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University of East Anglia: UEA Digital Repository |
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ftuniveastangl |
language |
unknown |
description |
The availability of dissolved nutrients such as nitrate under extreme low temperatures is a strong determinant in the development and growth of ice diatoms. Consequently we investigated regulation of photosynthesis in a mixed culture of three diatom species, which grew in chemostats at -1 °C, 15 µmol photons m-2 s-1 under N-limitation. When nitrogen is limiting, pigment-protein complexes are one of the most affected structures under low-light conditions. The loss of integral polar thylakoid components destabilized the bilayer structure of the membrane with consequences for lipid composition and the degree of fatty acid desaturation. N-Limitation caused a decrease in monogalactosydiacylglycerol (MGDG) and a simultaneous increase in bilayer forming digalactosyldiacylglycerol (DGDG). Their ratio MGDG:DGDG decreased from 3.4±0.1 to 1.1±0.4, while 20:5 n-3 fatty acids of chloroplast related phospholipid classes such as phosphatidylglycerol (PG) increased under N-limitation. These data reveal that lipids are important components, required to sustain membrane structure under a deficiency of integral membrane bound proteins and pigments. Nonetheless, energy conversion at photosystem II is still affected by N-limitation despite this structural regulation. Photosynthetic quantum yield (Fv/Fm) and electron transport rates decreased under N-limitation caused by an increasing amount of electron acceptors (second stable electron acceptor=QB) which had slower reoxidation kinetics. The energy surplus under these conditions is stored in triacylglycerols, the main energy sink in Antarctic sea ice diatoms under N-limitation. |
format |
Article in Journal/Newspaper |
author |
Mock, Thomas Kroon, Bernd M. A. |
spellingShingle |
Mock, Thomas Kroon, Bernd M. A. Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
author_facet |
Mock, Thomas Kroon, Bernd M. A. |
author_sort |
Mock, Thomas |
title |
Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
title_short |
Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
title_full |
Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
title_fullStr |
Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
title_full_unstemmed |
Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms |
title_sort |
photosynthetic energy conversion under extreme conditions—i: important role of lipids as structural modulators and energy sink under n-limited growth in antarctic sea ice diatoms |
publishDate |
2002 |
url |
https://ueaeprints.uea.ac.uk/id/eprint/33143/ https://doi.org/10.1016/S0031-9422(02)00216-9 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Sea ice |
genre_facet |
Antarc* Antarctic Sea ice |
op_relation |
Mock, Thomas and Kroon, Bernd M. A. (2002) Photosynthetic energy conversion under extreme conditions—I: Important role of lipids as structural modulators and energy sink under N-limited growth in Antarctic sea ice diatoms. Phytochemistry, 61 (1). pp. 41-51. ISSN 1873-3700 doi:10.1016/S0031-9422(02)00216-9 |
op_doi |
https://doi.org/10.1016/S0031-9422(02)00216-9 |
container_title |
Phytochemistry |
container_volume |
61 |
container_issue |
1 |
container_start_page |
41 |
op_container_end_page |
51 |
_version_ |
1767958014751408128 |