Cargando…

Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions

Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green alga...

Descripción completa

Detalles Bibliográficos
Autores principales: Verhoeven, Dana, van Amerongen, Herbert, Wientjes, Emilie
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9922397/
https://www.ncbi.nlm.nih.gov/pubmed/36478277
http://dx.doi.org/10.1093/plphys/kiac561
_version_ 1784887533031653376
author Verhoeven, Dana
van Amerongen, Herbert
Wientjes, Emilie
author_facet Verhoeven, Dana
van Amerongen, Herbert
Wientjes, Emilie
author_sort Verhoeven, Dana
collection PubMed
description Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green algae, a mobile pool of light-harvesting complex II (LHCII) associates with PSI, increasing its absorption cross-section and restoring the excitation balance. This is called state 2. Upon PSI overexcitation, this LHCII pool moves to PSII, leading to state 1. Whether the association/dissociation of LHCII with the photosystems occurs between thylakoid grana and thylakoid stroma lamellae during state transitions or within the same thylakoid region remains unclear. Furthermore, although state transitions are thought to be accompanied by changes in thylakoid macro-organization, this has never been observed directly in functional leaves. In this work, we used confocal fluorescence lifetime imaging to quantify state transitions in single Arabidopsis (Arabidopsis thaliana) chloroplasts in folio with sub-micrometer spatial resolution. The change in excitation-energy distribution between PSI and PSII was investigated at a range of excitation wavelengths between 475 and 665 nm. For all excitation wavelengths, the PSI/(PSI + PSII) excitation ratio was higher in state 2 than in state 1. We next imaged the local PSI/(PSI + PSII) excitation ratio for single chloroplasts in both states. The data indicated that LHCII indeed migrates between the grana and stroma lamellae during state transitions. Finally, fluorescence intensity images revealed that thylakoid macro-organization is largely unaffected by state transitions. This single chloroplast in folio imaging method will help in understanding how plants adjust their photosynthetic machinery to ever-changing light conditions.
format Online
Article
Text
id pubmed-9922397
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher Oxford University Press
record_format MEDLINE/PubMed
spelling pubmed-99223972023-02-13 Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions Verhoeven, Dana van Amerongen, Herbert Wientjes, Emilie Plant Physiol Research Article Oxygenic photosynthesis is driven by light absorption in photosystem I (PSI) and photosystem II (PSII). A balanced excitation pressure between PSI and PSII is required for optimal photosynthetic efficiency. State transitions serve to keep this balance. If PSII is overexcited in plants and green algae, a mobile pool of light-harvesting complex II (LHCII) associates with PSI, increasing its absorption cross-section and restoring the excitation balance. This is called state 2. Upon PSI overexcitation, this LHCII pool moves to PSII, leading to state 1. Whether the association/dissociation of LHCII with the photosystems occurs between thylakoid grana and thylakoid stroma lamellae during state transitions or within the same thylakoid region remains unclear. Furthermore, although state transitions are thought to be accompanied by changes in thylakoid macro-organization, this has never been observed directly in functional leaves. In this work, we used confocal fluorescence lifetime imaging to quantify state transitions in single Arabidopsis (Arabidopsis thaliana) chloroplasts in folio with sub-micrometer spatial resolution. The change in excitation-energy distribution between PSI and PSII was investigated at a range of excitation wavelengths between 475 and 665 nm. For all excitation wavelengths, the PSI/(PSI + PSII) excitation ratio was higher in state 2 than in state 1. We next imaged the local PSI/(PSI + PSII) excitation ratio for single chloroplasts in both states. The data indicated that LHCII indeed migrates between the grana and stroma lamellae during state transitions. Finally, fluorescence intensity images revealed that thylakoid macro-organization is largely unaffected by state transitions. This single chloroplast in folio imaging method will help in understanding how plants adjust their photosynthetic machinery to ever-changing light conditions. Oxford University Press 2022-12-08 /pmc/articles/PMC9922397/ /pubmed/36478277 http://dx.doi.org/10.1093/plphys/kiac561 Text en © The Author(s) 2022. Published by Oxford University Press on behalf of American Society of Plant Biologists. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (https://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
spellingShingle Research Article
Verhoeven, Dana
van Amerongen, Herbert
Wientjes, Emilie
Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title_full Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title_fullStr Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title_full_unstemmed Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title_short Single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
title_sort single chloroplast in folio imaging sheds light on photosystem energy redistribution during state transitions
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9922397/
https://www.ncbi.nlm.nih.gov/pubmed/36478277
http://dx.doi.org/10.1093/plphys/kiac561
work_keys_str_mv AT verhoevendana singlechloroplastinfolioimagingshedslightonphotosystemenergyredistributionduringstatetransitions
AT vanamerongenherbert singlechloroplastinfolioimagingshedslightonphotosystemenergyredistributionduringstatetransitions
AT wientjesemilie singlechloroplastinfolioimagingshedslightonphotosystemenergyredistributionduringstatetransitions