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The plastoquinone pool outside the thylakoid membrane serves in plant photoprotection as a reservoir of singlet oxygen scavengers.
- Source :
-
Plant, cell & environment [Plant Cell Environ] 2018 Oct; Vol. 41 (10), pp. 2277-2287. Date of Electronic Publication: 2018 Jun 29. - Publication Year :
- 2018
-
Abstract
- The Arabidopsis vte1 mutant is devoid of tocopherol and plastochromanol (PC-8). When exposed to excess light energy, vte1 produced more singlet oxygen ( <superscript>1</superscript> O <subscript>2</subscript> ) and suffered from extensive oxidative damage compared with the wild type. Here, we show that overexpressing the solanesyl diphosphate synthase 1 (SPS1) gene in vte1 induced a marked accumulation of total plastoquinone (PQ-9) and rendered the vte1 SPS1oex plants tolerant to photooxidative stress, indicating that PQ-9 can replace tocopherol and PC-8 in photoprotection. High total PQ-9 levels were associated with a noticeable decrease in <superscript>1</superscript> O <subscript>2</subscript> production and higher levels of Hydroxyplastoquinone (PQ-C), a <superscript>1</superscript> O <subscript>2</subscript> -specific PQ-9 oxidation product. The extra PQ-9 molecules in the vte1 SPS1oex plants were stored in the plastoglobules and the chloroplast envelopes, rather than in the thylakoid membranes, whereas PQ-C was found almost exclusively in the thylakoid membranes. Upon exposure of wild-type plants to high light, the thylakoid PQ-9 pool decreased, whereas the extrathylakoid pool remained unchanged. In vte1 and vte1 SPS1oex plants, the PQ-9 losses in high light were strongly amplified, affecting also the extrathylakoid pool, and PQ-C was found in high amounts in the thylakoids. We conclude that the thylakoid PQ-9 pool acts as a <superscript>1</superscript> O <subscript>2</subscript> scavenger and is replenished from the extrathylakoid stock.<br /> (© 2018 John Wiley & Sons Ltd.)
- Subjects :
- Alkyl and Aryl Transferases metabolism
Arabidopsis Proteins metabolism
Chlorophyll metabolism
Chloroplasts metabolism
Chromatography, High Pressure Liquid
Electron Spin Resonance Spectroscopy
Light
Lipid Peroxidation
Oxidative Stress radiation effects
Free Radical Scavengers metabolism
Plastoquinone metabolism
Singlet Oxygen metabolism
Thylakoids metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1365-3040
- Volume :
- 41
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- Plant, cell & environment
- Publication Type :
- Academic Journal
- Accession number :
- 29601642
- Full Text :
- https://doi.org/10.1111/pce.13202