The role of Delta pH-dependent dissipation of excitation energy in protecting photosystem II against light-induced damage in Arabidopsis thaliana
Articolo
Data di Pubblicazione:
2002
Citazione:
The role of Delta pH-dependent dissipation of excitation energy in protecting photosystem II against light-induced damage in Arabidopsis thaliana / T. Graßes, P. Pesaresi, F. Schiavon, C. Varotto, F. Salamini,
P. Jahns, D. Leister. - In: PLANT PHYSIOLOGY AND BIOCHEMISTRY. - ISSN 0981-9428. - 40:1(2002 Jan), pp. 41-49.
Abstract:
The Arabidopsis thaliana subunit PsbS of photosystem II (PSII) is essential for the non-photochemical quenching of chlorophyll
fluorescence and thus for ΔpH-dependent energy dissipation (qE). As a result of the excision of an En-transposon, a frameshift mutation
in the psbS gene was obtained, which results in the complete absence of the PsbS protein and of qE. Two-dimensional gel analyses of
thylakoid membranes indicated that the depletion of PsbS has no effect on PSII composition, excluding a structural role for PsbS in the
organization of the PSII antenna. The susceptibility of mutant plants to photoinactivation of PSII was significantly increased during exposure
to high light for up to 8 h. Divergence of mutant plants from wild-type levels of photoinactivation were most pronounced during the first
2 h of illumination, while after longer exposure times the rate of PSII inactivation were similar in both genotypes. The increased PSII
inactivation in the mutant was not accompanied by an increased rate of D1 protein degradation, and recovery of PSII activity in the mutant
under low light was similar or even faster in comparison to wild-type plants. However, growth under high light intensities resulted in
decreased growth rates of psbs mutant plants. We conclude that energy dissipation in PSII related to qE is not primarily required for the
protection of PSII against light-induced destruction, but may rather be involved in reducing the electron pressure on the photosynthetic
electron transport chain at saturating light intensities. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
ΔpH-dependent quenching; Arabidopsis thaliana; Chl; Chlorophyll; Mutant; Non-photochemical quenching; NPQ; PFD; Photoinhibitory quenching; Photoprotection; Photosynthetically active flux density; Photosystem II; PsbS; qE; qI
Elenco autori:
T. Graßes, P. Pesaresi, F. Schiavon, C. Varotto, F. Salamini,
P. Jahns, D. Leister
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