In vivo cytochrome and alternative pathway respiration in leaves of Arabidopsis thaliana plants with altered alternative oxidase under different light conditions
Author
Summary, in English
The in vivo activity of the alternative pathway (V-alt) has been studied using the oxygen isotope fractionation method in leaves of Arabidopsis thaliana modified for the expression of the AtAOX1a gene by anti-sense (AS-12) or overexpression (XX-2). Under non-stressful conditions, V-alt was similar in all plant lines regardless of its different alternative pathway capacities (V-alt). Total leaf respiration (V-t) and V-alt were directly related to growth light conditions while electron partitioning between the cytochrome pathway (CP) and alternative pathway (AP) was unchanged by light levels. Interestingly, the AP functioned at full capacity in anti-sense plants under both growth light conditions. The role of the AP in response to a high light stress induced by short-term high light treatment (HLT) was also studied. In wild type and XX-2, both CP and AP rates increased proportionally after HLT while in AS-12, where the AP was unable to increase its rate, the CP accommodated all the increase in respiration. The results obtained under high light stress suggest that flexibility in the response of the mitochondrial electron transport chain is involved in sustaining photosynthetic rates in response to this stress while the saturated AP in AS-12 plants may contribute to the observed increase in photoinhibition.
Department/s
Publishing year
2011
Language
English
Pages
1373-1383
Publication/Series
Plant, Cell and Environment
Volume
34
Issue
8
Links
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Biological Sciences
Keywords
- high light
- oxygen isotope fractionation
- photoinhibition
- plant
- mitochondria
Status
Published
Research group
- Plant Biology
ISBN/ISSN/Other
- ISSN: 0140-7791