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Higher Plant Photosystem II Light-Harvesting Antenna, Not the Reaction Center, Determines the Excited-State Lifetime—Both the Maximum and the Nonphotochemically Quenched

Belgio, Erica ; Johnson, Matthew P. ; Jurić, Snježana ; Ruban, Alexander V.

Biophysical journal, 2012-06, Vol.102 (12), p.2761-2771 [Periódico revisado por pares]

United States: Elsevier Inc

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Título:
Higher Plant Photosystem II Light-Harvesting Antenna, Not the Reaction Center, Determines the Excited-State Lifetime—Both the Maximum and the Nonphotochemically Quenched
Autor: Belgio, Erica ; Johnson, Matthew P. ; Jurić, Snježana ; Ruban, Alexander V.
Assuntos: Arabidopsis - cytology ; Arabidopsis - drug effects ; Arabidopsis - growth & development ; Arabidopsis - metabolism ; Arabidopsis thaliana ; Biophysics ; Chlorophyll ; Chlorophyll - chemistry ; Chlorophyll - metabolism ; Chloroplasts ; Flowers & plants ; fluorescence ; light harvesting complex ; Light-Harvesting Protein Complexes - metabolism ; lincomycin ; Lincomycin - pharmacology ; Luminescence quenching ; Membrane ; Photochemical Processes ; Photochemistry ; Photosynthesis - drug effects ; photosystem II ; Photosystem II Protein Complex - metabolism ; protein synthesis inhibitors ; Spectrometry, Fluorescence ; thylakoids ; Thylakoids - drug effects ; Thylakoids - metabolism ; Xanthophylls - metabolism
É parte de: Biophysical journal, 2012-06, Vol.102 (12), p.2761-2771
Notas: http://dx.doi.org/10.1016/j.bpj.2012.05.004
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Descrição: The maximum chlorophyll fluorescence lifetime in isolated photosystem II (PSII) light-harvesting complex (LHCII) antenna is 4 ns; however, it is quenched to 2 ns in intact thylakoid membranes when PSII reaction centers (RCIIs) are closed (Fm). It has been proposed that the closed state of RCIIs is responsible for the quenching. We investigated this proposal using a new, to our knowledge, model system in which the concentration of RCIIs was highly reduced within the thylakoid membrane. The system was developed in Arabidopsis thaliana plants under long-term treatment with lincomycin, a chloroplast protein synthesis inhibitor. The treatment led to 1), a decreased concentration of RCIIs to 10% of the control level and, interestingly, an increased antenna component; 2), an average reduction in the yield of photochemistry to 0.2; and 3), an increased nonphotochemical chlorophyll fluorescence quenching (NPQ). Despite these changes, the average fluorescence lifetimes measured in Fm and Fm′ (with NPQ) states were nearly identical to those obtained from the control. A 77 K fluorescence spectrum analysis of treated PSII membranes showed the typical features of preaggregation of LHCII, indicating that the state of LHCII antenna in the dark-adapted photosynthetic membrane is sufficient to determine the 2 ns Fm lifetime. Therefore, we conclude that the closed RCs do not cause quenching of excitation in the PSII antenna, and play no role in the formation of NPQ.
Editor: United States: Elsevier Inc
Idioma: Inglês

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Higher Plant Photosystem II Light-Harvesting Antenna, Not the Reaction Center, Determines the Excited-State Lifetime—Both the Maximum and the Nonphotochemically Quenched

Belgio, Erica ; Johnson, Matthew P. ; Jurić, Snježana ; Ruban, Alexander V.

United States: Elsevier Inc

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