Format

Send to

Choose Destination

See 1 citation found by title matching your search:

Plant J. 2013 Nov;76(4):568-79. doi: 10.1111/tpj.12314. Epub 2013 Oct 3.

Interaction between avoidance of photon absorption, excess energy dissipation and zeaxanthin synthesis against photooxidative stress in Arabidopsis.

Author information

1
Dipartimento di Biotecnologie, Università di Verona, 37134, Italy.

Abstract

Plants evolved photoprotective mechanisms in order to counteract the damaging effects of excess light in oxygenic environments. Among them, chloroplast avoidance and non-photochemical quenching concur in reducing the concentration of chlorophyll excited states in the photosynthetic apparatus to avoid photooxidation. We evaluated their relative importance in regulating excitation pressure on photosystem II. To this aim, genotypes were constructed carrying mutations impairing the chloroplast avoidance response (phot2) as well as mutations affecting the biosynthesis of the photoprotective xanthophyll zeaxanthin (npq1) or the activation of non-photochemical quenching (npq4), followed by evaluation of their photosensitivity in vivo. Suppression of avoidance response resulted in oxidative stress under excess light at low temperature, while removing either zeaxanthin or PsbS had a milder effect. The double mutants phot2 npq1 and phot2 npq4 showed the highest sensitivity to photooxidative stress, indicating that xanthophyll cycle and qE have additive effects over the avoidance response. The interactions between non-photochemical quenching and avoidance responses were studied by analyzing the kinetics of fluorescence decay and recovery at different light intensities. phot2 fluorescence decay lacked a component, here named as qM. This kinetic component linearly correlated with the leaf transmittance changes due to chloroplast relocation induced by white light and was absent when red light was used as actinic source. On these basis we conclude that a decrease in leaf optical density affects the apparent non-photochemical quenching (NPQ) rise kinetic. Thus, excess light-induced fluorescence decrease is in part due to avoidance of photon absorption rather than to a genuine quenching process.

KEYWORDS:

Arabidopsis thaliana; chloroplast avoidance movement; lipid peroxidation; non-photochemical quenching; photoprotection; zeaxanthin

PMID:
24033721
DOI:
10.1111/tpj.12314
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center