| A two-photon excitation study on the role of carotenoid dark states in the regulation of plant photosynthesis. | |
| | |
MedLine Citation:
|
PMID: 17211584 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Plants are exposed to sun light intensities that vary rapidly over several orders of magnitude during a typical day. It is known that the regulation of photosynthetic activity under these circumstances is essential for the survival and fitness of natural and gene modified plants. A quick balancing between utilization and dissipation of absorbed light energy ensures optimized levels of CO(2) fixation and protection from photo damage by excessive light-irradiation. Despite intensive investigations the biophysical mechanisms of these regulation processes are still poorly understood. Potentially involved singlet states of carotenoids are optically "dark" and so far it was impossible to investigate their role directly in living plants by conventional absorption or fluorescence spectroscopy. Here, we show by selective two-photon excitation of the carotenoid dark states in plant that a dominant part of the regulation is correlated with a substantial change in the energy transfer between these states and the chlorophylls (Chl). The results support a considerable role of the molecular gear shift model in which a reversible and step-wise enzymatic modification of the electronic structure of xanthophyll carotenoids enables a switching between carotenoid-to-Chl light-harvesting and Chl-to-carotenoid quenching. The shifting can be observed in real time in any plant. Treatment with the xanthophyll cycle inhibitor dithiothreitol slowed down both the light adaptation and the carotenoid-Chl energy flow changes to the same extent. Based on these results, we propose a biophysical quenching model in which both carotenoid dark states and radical cations contribute to the dissipation of excessive excitation energy. |
| | |
Authors:
|
Axel Wehling; Peter J Walla |
Related Documents
:
|
15208324 - The three isoforms of the light-harvesting complex ii: spectroscopic features, trimer f... 21766944 - Ab initio and long-range investigation of the Ω((+∕-)) states of nak dissociating ad... 18818914 - Model for fluorescence quenching in light harvesting complex ii in different aggregatio... 16228424 - Characterization of processes responsible for the distinct effect of herbicides dcmu an... 18457944 - Porous nanosheet-based zno microspheres for the construction of direct electrochemical ... 19801774 - Facile synthesis of manganite nanowires: phase transitions and their electrocatalysis p... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2007-01-09 |
Journal Detail:
|
Title: Photosynthesis research Volume: 90 ISSN: 0166-8595 ISO Abbreviation: Photosyn. Res. Publication Date: 2006 Nov |
Date Detail:
|
Created Date: 2007-01-19 Completed Date: 2007-05-25 Revised Date: 2007-05-29 |
Medline Journal Info:
|
Nlm Unique ID: 100954728 Medline TA: Photosynth Res Country: Netherlands |
Other Details:
|
Languages: eng Pagination: 101-10 Citation Subset: IM |
Affiliation:
|
Department for Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, Technical University of Brunswick, Hans-Sommerstr. 10, 38106, Braunschweig, Germany. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Arabidopsis
/
physiology* Carotenoids / metabolism* Darkness* Energy Transfer Photons Photosynthesis / physiology* Poaceae / physiology* Spectrometry, Fluorescence Time Factors Xanthophylls / metabolism |
| Chemical | |
Reg. No./Substance:
|
0/Xanthophylls; 126-29-4/violaxanthin; 144-68-3/zeaxanthin; 36-88-4/Carotenoids |
| Comments/Corrections | |
Erratum In:
|
Photosynth Res. 2006 Dec;90(3):263-4 |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: A method for quantitative analysis of spatially variable physiological processes across leaf surface...
Next Document: The positive role of lumbar puncture in the diagnosis of Vogt-Koyanagi-Harada disease: lymphocyte su...