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Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms
Photoacclimation by strains of Haslea “blue” diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction–recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m(−2) s(−1) photosynthetic avail...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Netherlands
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6182385/ https://www.ncbi.nlm.nih.gov/pubmed/29663190 http://dx.doi.org/10.1007/s11120-018-0508-x |
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author | Perkins, R. Williamson, C. Lavaud, J. Mouget, J.-L. Campbell, D. A. |
author_facet | Perkins, R. Williamson, C. Lavaud, J. Mouget, J.-L. Campbell, D. A. |
author_sort | Perkins, R. |
collection | PubMed |
description | Photoacclimation by strains of Haslea “blue” diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction–recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m(−2) s(−1) photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σ(PSII)′) or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σ(PSII)′ in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. Q(A)(−) oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction–recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11120-018-0508-x) contains supplementary material, which is available to authorised users. |
format | Online Article Text |
id | pubmed-6182385 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Springer Netherlands |
record_format | MEDLINE/PubMed |
spelling | pubmed-61823852018-10-22 Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms Perkins, R. Williamson, C. Lavaud, J. Mouget, J.-L. Campbell, D. A. Photosynth Res Original Article Photoacclimation by strains of Haslea “blue” diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction–recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m(−2) s(−1) photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σ(PSII)′) or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σ(PSII)′ in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. Q(A)(−) oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction–recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11120-018-0508-x) contains supplementary material, which is available to authorised users. Springer Netherlands 2018-04-16 2018 /pmc/articles/PMC6182385/ /pubmed/29663190 http://dx.doi.org/10.1007/s11120-018-0508-x Text en © The Author(s) 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Original Article Perkins, R. Williamson, C. Lavaud, J. Mouget, J.-L. Campbell, D. A. Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title | Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title_full | Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title_fullStr | Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title_full_unstemmed | Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title_short | Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms |
title_sort | time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in haslea diatoms |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6182385/ https://www.ncbi.nlm.nih.gov/pubmed/29663190 http://dx.doi.org/10.1007/s11120-018-0508-x |
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