Journal
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
Volume 1817, Issue 12, Pages 2158-2165Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.bbabio.2012.09.011
Keywords
Singlet oxygen; Photosynthesis; Non-photochemical quenching; Cyclic electron flow; Photoinhibition; Arabidopsis
Categories
Funding
- Agence Nationale de Recherche [ANR-09-BLAN-0005-01]
- EU FP7 Marie Curie Initial Training Network HARVEST [238017]
- Agence Nationale de la Recherche (ANR) [ANR-09-BLAN-0005] Funding Source: Agence Nationale de la Recherche (ANR)
Ask authors/readers for more resources
The PsbS protein is recognised in higher plants as an important component in dissipating excess light energy via its regulation of non-photochemical quenching. We investigated photosynthetic responses in the arabidopsis npq4 mutant, which lacks PsbS, and in a mutant over-expressing PsbS (oePsbS). Growth under low light led to npq4 and wild-type plants being visibly indistinguishable, but induced a phenotype in oePsbS plants, which were smaller and had shorter flowering spikes. Here we report that chloroplasts from npq4 generated more singlet oxygen (O-1(2)) than those from oePsbS. This accompanied a higher extent of photosystern II photoinhibition of leaves from npq4 plants. In contrast, oePsbS was more damaged by high light than npq4 and the wild-type at the level of photosystem I. The plastoquinone pool, as measured by thermoluminescence, was more oxidised in the oePsbS than in npq4, whilst the amount of photo-oxidisable P-700, as probed with actinic light or saturating flashes, was higher in oePsbS compared to wild-type and npq4. Taken together, this indicates that the level of PsbS has a regulatory role in cyclic electron flow. Overall, we show that under high light oePsbS plants were more protected from O-1(2) at the level of photosystem whereas lack of cyclic electron flow rendered them susceptible to damage at photosystem I. Cyclic electron flow is concluded to be essential for protecting photosystem I from high light stress. (C) 2012 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available