scholarly journals Induction of Nonphotochemical Energy Dissipation and Absorbance Changes in Leaves (Evidence for Changes in the State of the Light-Harvesting System of Photosystem II in Vivo)

1993 ◽  
Vol 102 (3) ◽  
pp. 741-750 ◽  
Author(s):  
A. V. Ruban ◽  
A. J. Young ◽  
P. Horton
Keyword(s):  
Energy Dissipation ◽  
Photosystem Ii ◽  
Light Harvesting ◽  
The State ◽  
Absorbance Changes

scholarly journals Allosteric regulation of the light-harvesting system of photosystem II

2000 ◽  
Vol 355 (1402) ◽  
pp. 1361-1370 ◽  
Author(s):  
Peter Horton ◽  
Alexander V. Ruban ◽  
Mark Wentworth
Keyword(s):  
Photosystem Ii ◽  
Xanthophyll Cycle ◽  
Light Harvesting ◽  
Allosteric Regulation ◽  
Photochemical Quenching ◽  
Protein Subunit ◽  
Ps Ii ◽  
Non Photochemical Quenching

Non–photochemical quenching of chlorophyll fluorescence (NPQ) is symptomatic of the regulation of energy dissipation by the light–harvesting antenna of photosystem II (PS II). The kinetics of NPQ in both leaves and isolated chloroplasts are determined by the transthylakoid ΔpH and the de–epoxidation state of the xanthophyll cycle. In order to understand the mechanism and regulation of NPQ we have adopted the approaches commonly used in the study of enzyme–catalysed reactions. Steady–state measurements suggest allosteric regulation of NPQ, involving control by the xanthophyll cycle carotenoids of a protonationdependent conformational change that transforms the PS II antenna from an unquenched to a quenched state. The features of this model were confirmed using isolated light–harvesting proteins. Analysis of the rate of induction of quenching both in vitro and in vivo indicated a bimolecular second–order reaction; it is suggested that quenching arises from the reaction between two fluorescent domains, possibly within a single protein subunit. A universal model for this transition is presented based on simple thermodynamic principles governing reaction kinetics.

scholarly journals Correlation between changes in light energy distribution and changes in thylakoid membrane polypeptide phosphorylation in Chlamydomonas reinhardtii.

1984 ◽  
Vol 98 (1) ◽  
pp. 1-7 ◽  
Author(s):  
F A Wollman ◽  
P Delepelaire
Keyword(s):  
Photosystem Ii ◽  
Chlamydomonas Reinhardtii ◽  
Redox State ◽  
Light Harvesting ◽  
Anaerobic Treatment ◽  
Intact Cells ◽  
Light Harvesting Complex ◽  
Plastoquinone Pool

We have used a new method to extensively modify the redox state of the plastoquinone pool in Chlamydomonas reinhardtii intact cells. This was achieved by an anaerobic treatment that inhibits the chlororespiratory pathway recently described by P. Bennoun (Proc. Natl. Acad. Sci. USA, 1982, 79:4352-4356). A state I (plus 3,4-dichlorophenyl-1,1-dimethylurea) leads to anaerobic state transition induced a decrease in the maximal fluorescence yield at room temperature and in the FPSII/FPSI ratio at 77 degrees K, which was three times larger than in a classical state I leads to state II transition. The fluorescence changes observed in vivo were similar in amplitude to those observed in vitro upon transfer to the light of dark-adapted, broken chloroplasts incubated in the presence of ATP. We then compared the phosphorylation pattern of thylakoid polypeptides in C. reinhardtii in vitro and in vivo using gamma-[32P]ATP and [32P]orthophosphate labeling, respectively. The same set of polypeptides, mainly light-harvesting complex polypeptides, was phosphorylated in both cases. We observed that this phosphorylation process is reversible and is mediated by the redox state of the plastoquinone pool in vivo as well as in vitro. Similar changes of even larger amplitude were observed with the F34 mutant intact cells lacking in photosystem II centers. The presence of the photosystem II centers is then not required for the occurrence of the plastoquinone-mediated phosphorylation of light-harvesting complex polypeptides.

scholarly journals In Vivo Identification of Photosystem II Light Harvesting Complexes Interacting with PHOTOSYSTEM II SUBUNIT S

2015 ◽  
Vol 168 (4) ◽  
pp. 1747-1761 ◽  
Author(s):  
Caterina Gerotto ◽  
Cinzia Franchin ◽  
Giorgio Arrigoni ◽  
Tomas Morosinotto
Keyword(s):  
Photosystem Ii ◽  
Light Harvesting ◽  
Light Harvesting Complexes

scholarly journals Phosphorylation of Light-harvesting Complex II and Photosystem II Core Proteins Shows Different Irradiance-dependent Regulation in Vivo

1997 ◽  
Vol 272 (48) ◽  
pp. 30476-30482 ◽  
Author(s):  
Eevi Rintamäki ◽  
Mervi Salonen ◽  
Ulla-Maija Suoranta ◽  
Inger Carlberg ◽  
Bertil Andersson ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Light Harvesting ◽  
Light Harvesting Complex ◽  
Complex Ii ◽  
Core Proteins ◽  
Light Harvesting Complex Ii

scholarly journals Live-cell imaging of photosystem II antenna dissociation during state transitions

2009 ◽  
Vol 107 (5) ◽  
pp. 2337-2342 ◽  
Author(s):  
Masakazu Iwai ◽  
Makio Yokono ◽  
Noriko Inada ◽  
Jun Minagawa
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Light Harvesting ◽  
Live Cells ◽  
State Transitions ◽  
Fluorescence Lifetime Imaging ◽  
Energy Redistribution ◽  
Dominant Component ◽  
Light Harvesting Antenna

Plants and green algae maintain efficient photosynthesis under changing light environments by adjusting their light-harvesting capacity. It has been suggested that energy redistribution is brought about by shuttling the light-harvesting antenna complex II (LHCII) between photosystem II (PSII) and photosystem I (PSI) (state transitions), but such molecular remodeling has never been demonstrated in vivo. Here, using chlorophyll fluorescence lifetime imaging microscopy, we visualized phospho-LHCII dissociation from PSII in live cells of the green alga Chlamydomonas reinhardtii. Induction of energy redistribution in wild-type cells led to an increase in, and spreading of, a 250-ps lifetime chlorophyll fluorescence component, which was not observed in the stt7 mutant incapable of state transitions. The 250-ps component was also the dominant component in a mutant containing the light-harvesting antenna complexes but no photosystems. The appearance of the 250-ps component was accompanied by activation of LHCII phosphorylation, supporting the visualization of phospho-LHCII dissociation. Possible implications of the unbound phospho-LHCII on energy dissipation are discussed.

scholarly journals Singlet Energy Dissipation in the Photosystem II Light-Harvesting Complex Does Not Involve Energy Transfer to Carotenoids

ChemPhysChem ◽  
2010 ◽  
Vol 11 (6) ◽  
pp. 1289-1296 ◽  
Author(s):  
Marc G. Müller ◽  
Petar Lambrev ◽  
Michael Reus ◽  
Emilie Wientjes ◽  
Roberta Croce ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Energy Dissipation ◽  
Photosystem Ii ◽  
Light Harvesting ◽  
Light Harvesting Complex
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