Abstract
Mitochondrial alternative oxidase (AOX), the unique respiratory terminal oxidase in plants, catalyzes the energy-wasteful cyanide (CN)-resistant respiration. Although it has been demonstrated that leaf AOX is up-regulated under high-light (HL) conditions, the in vivo mechanism of AOX up-regulation by light is still unknown. In the present study, we examined whether the photo-oxidative stress in the chloroplast modulates mitochondrial respiratory properties, especially the AOX capacity, using Arabidopsis leaf-variegated mutant yellow variegated 2 (var2) and exposing plants to HL. var2 mutants lack FtsH2 metalloprotease required for the repair of damaged PSII. Indeed, var2-1 suffered from photo-oxidative stress even before the HL treatments. While the activities of tricarboxylic acid cycle enzymes and cytochrome c oxidase in var2-1 were almost identical to those in the wild type, the amount of AOX protein and the CN-resistant respiration rate were higher in var2-1. Real-time PCR analysis revealed that HL treatment induced the expression of some energy-dissipating respiratory genes, including AOX1a, NDB2 and UCP5, more strongly in var2-1. Western blotting using var2-1 leaf extracts specific to green or white sectors, containing functional or non-functional photosynthetic apparatus, respectively, revealed that more AOX protein was induced in the green sectors by the HL treatment. These results indicate that photo-oxidative stress by excess light is involved in the regulation of respiratory gene expression and the modulation of respiratory properties, especially the AOX up-regulation.
| Original language | English |
|---|---|
| Pages (from-to) | 592-603 |
| Number of pages | 12 |
| Journal | Plant and Cell Physiology |
| Volume | 49 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 2008 |
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Keywords
- Alternative oxidase
- Arabidopsis thaliana
- Energy-dissipating respiration
- Photo-oxidative stress
- Yellow variegated 2
ASJC Scopus subject areas
- Plant Science
- Physiology
- Cell Biology
- Medicine(all)
Cite this
Influence of chloroplastic photo-oxidative stress on mitochondrial alternative oxidase capacity and respiratory properties : A case study with arabidopsis yellow variegated 2. / Yoshida, Keisuke; Watanabe, Chihiro; Kato, Yusuke; Sakamoto, Wataru; Noguchi, Ko.
In: Plant and Cell Physiology, Vol. 49, No. 4, 04.2008, p. 592-603.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Influence of chloroplastic photo-oxidative stress on mitochondrial alternative oxidase capacity and respiratory properties
T2 - A case study with arabidopsis yellow variegated 2
AU - Yoshida, Keisuke
AU - Watanabe, Chihiro
AU - Kato, Yusuke
AU - Sakamoto, Wataru
AU - Noguchi, Ko
PY - 2008/4
Y1 - 2008/4
N2 - Mitochondrial alternative oxidase (AOX), the unique respiratory terminal oxidase in plants, catalyzes the energy-wasteful cyanide (CN)-resistant respiration. Although it has been demonstrated that leaf AOX is up-regulated under high-light (HL) conditions, the in vivo mechanism of AOX up-regulation by light is still unknown. In the present study, we examined whether the photo-oxidative stress in the chloroplast modulates mitochondrial respiratory properties, especially the AOX capacity, using Arabidopsis leaf-variegated mutant yellow variegated 2 (var2) and exposing plants to HL. var2 mutants lack FtsH2 metalloprotease required for the repair of damaged PSII. Indeed, var2-1 suffered from photo-oxidative stress even before the HL treatments. While the activities of tricarboxylic acid cycle enzymes and cytochrome c oxidase in var2-1 were almost identical to those in the wild type, the amount of AOX protein and the CN-resistant respiration rate were higher in var2-1. Real-time PCR analysis revealed that HL treatment induced the expression of some energy-dissipating respiratory genes, including AOX1a, NDB2 and UCP5, more strongly in var2-1. Western blotting using var2-1 leaf extracts specific to green or white sectors, containing functional or non-functional photosynthetic apparatus, respectively, revealed that more AOX protein was induced in the green sectors by the HL treatment. These results indicate that photo-oxidative stress by excess light is involved in the regulation of respiratory gene expression and the modulation of respiratory properties, especially the AOX up-regulation.
AB - Mitochondrial alternative oxidase (AOX), the unique respiratory terminal oxidase in plants, catalyzes the energy-wasteful cyanide (CN)-resistant respiration. Although it has been demonstrated that leaf AOX is up-regulated under high-light (HL) conditions, the in vivo mechanism of AOX up-regulation by light is still unknown. In the present study, we examined whether the photo-oxidative stress in the chloroplast modulates mitochondrial respiratory properties, especially the AOX capacity, using Arabidopsis leaf-variegated mutant yellow variegated 2 (var2) and exposing plants to HL. var2 mutants lack FtsH2 metalloprotease required for the repair of damaged PSII. Indeed, var2-1 suffered from photo-oxidative stress even before the HL treatments. While the activities of tricarboxylic acid cycle enzymes and cytochrome c oxidase in var2-1 were almost identical to those in the wild type, the amount of AOX protein and the CN-resistant respiration rate were higher in var2-1. Real-time PCR analysis revealed that HL treatment induced the expression of some energy-dissipating respiratory genes, including AOX1a, NDB2 and UCP5, more strongly in var2-1. Western blotting using var2-1 leaf extracts specific to green or white sectors, containing functional or non-functional photosynthetic apparatus, respectively, revealed that more AOX protein was induced in the green sectors by the HL treatment. These results indicate that photo-oxidative stress by excess light is involved in the regulation of respiratory gene expression and the modulation of respiratory properties, especially the AOX up-regulation.
KW - Alternative oxidase
KW - Arabidopsis thaliana
KW - Energy-dissipating respiration
KW - Photo-oxidative stress
KW - Yellow variegated 2
UR - http://www.scopus.com/inward/record.url?scp=44349189837&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44349189837&partnerID=8YFLogxK
U2 - 10.1093/pcp/pcn031
DO - 10.1093/pcp/pcn031
M3 - Article
C2 - 18296449
AN - SCOPUS:44349189837
VL - 49
SP - 592
EP - 603
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
SN - 0032-0781
IS - 4
ER -