Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions
- Autores
- Bartoli, Carlos Guillermo; Gomez, Facundo Martin; Gergoff, Gustavo; Guiamet, Juan José; Puntarulo, Susana
- Año de publicación
- 2005
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- The aim of this study was to explore the role of the mitochondrial alternative oxidase (AOX) in the protection of photosynthesis during drought in wheat leaves. The relative water contents of water-replete and drought-exposed wheat plants were 97.2±0.3 and 75±2, respectively. Drought increased the amount of leaf AOX protein and also enhanced the rate of AOX-dependent O 2 uptake by the respiratory electron transport chain. The amount of the reduced, active form of the AOX protein was specifically increased by drought. The AOX inhibitor salicylhydroxamic acid (1 mM; SHAM) inhibited 70% of AOX activity in vivo in both water-replete and drought-exposed plants. Plants treated with SHAM were then exposed to low (100), high (350), or excess light (800 μmol photons m -2 s -1 ) for 90 min. SHAM did not modify chlorophyll a fluorescence quenching parameters in water-replete controls after any of these treatments. However, while the maximal quantum yield of photosystem II (PSII) electron transport (F v /F m ) was not affected by SHAM, the immediate quantum yield of PSII electron transport (Φ PSII ) and photochemical quenching (qP) were gradually reduced by increasing irradiance in SHAM-treated drought-exposed plants, the decrease being most pronounced at the highest irradiance. Non-photochemical quenching (NPO) reached near maximum levels in plants subjected to drought at high irradiance. However, a combination of drought and low light caused an intermediate increase in NPO, which attained higher values when AOX was inhibited. Taken together, these results show that up-regulation of the respiratory AOX pathway protects the photosynthetic electron transport chain from the harmful effects of excess light.
Instituto de Fisiología Vegetal - Materia
-
Ciencias Naturales
Alternative oxidase
Chlorophyll fluorescence
Drought
Photoprotection
Respiration
Wheat - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/83404
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Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditionsBartoli, Carlos GuillermoGomez, Facundo MartinGergoff, GustavoGuiamet, Juan JoséPuntarulo, SusanaCiencias NaturalesAlternative oxidaseChlorophyll fluorescenceDroughtPhotoprotectionRespirationWheatThe aim of this study was to explore the role of the mitochondrial alternative oxidase (AOX) in the protection of photosynthesis during drought in wheat leaves. The relative water contents of water-replete and drought-exposed wheat plants were 97.2±0.3 and 75±2, respectively. Drought increased the amount of leaf AOX protein and also enhanced the rate of AOX-dependent O 2 uptake by the respiratory electron transport chain. The amount of the reduced, active form of the AOX protein was specifically increased by drought. The AOX inhibitor salicylhydroxamic acid (1 mM; SHAM) inhibited 70% of AOX activity in vivo in both water-replete and drought-exposed plants. Plants treated with SHAM were then exposed to low (100), high (350), or excess light (800 μmol photons m -2 s -1 ) for 90 min. SHAM did not modify chlorophyll a fluorescence quenching parameters in water-replete controls after any of these treatments. However, while the maximal quantum yield of photosystem II (PSII) electron transport (F v /F m ) was not affected by SHAM, the immediate quantum yield of PSII electron transport (Φ PSII ) and photochemical quenching (qP) were gradually reduced by increasing irradiance in SHAM-treated drought-exposed plants, the decrease being most pronounced at the highest irradiance. Non-photochemical quenching (NPO) reached near maximum levels in plants subjected to drought at high irradiance. However, a combination of drought and low light caused an intermediate increase in NPO, which attained higher values when AOX was inhibited. Taken together, these results show that up-regulation of the respiratory AOX pathway protects the photosynthetic electron transport chain from the harmful effects of excess light.Instituto de Fisiología Vegetal2005info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1269-1276http://sedici.unlp.edu.ar/handle/10915/83404enginfo:eu-repo/semantics/altIdentifier/issn/0022-0957info:eu-repo/semantics/altIdentifier/doi/10.1093/jxb/eri111info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:15:46Zoai:sedici.unlp.edu.ar:10915/83404Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:46.98SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
title |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
spellingShingle |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions Bartoli, Carlos Guillermo Ciencias Naturales Alternative oxidase Chlorophyll fluorescence Drought Photoprotection Respiration Wheat |
title_short |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
title_full |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
title_fullStr |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
title_full_unstemmed |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
title_sort |
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions |
dc.creator.none.fl_str_mv |
Bartoli, Carlos Guillermo Gomez, Facundo Martin Gergoff, Gustavo Guiamet, Juan José Puntarulo, Susana |
author |
Bartoli, Carlos Guillermo |
author_facet |
Bartoli, Carlos Guillermo Gomez, Facundo Martin Gergoff, Gustavo Guiamet, Juan José Puntarulo, Susana |
author_role |
author |
author2 |
Gomez, Facundo Martin Gergoff, Gustavo Guiamet, Juan José Puntarulo, Susana |
author2_role |
author author author author |
dc.subject.none.fl_str_mv |
Ciencias Naturales Alternative oxidase Chlorophyll fluorescence Drought Photoprotection Respiration Wheat |
topic |
Ciencias Naturales Alternative oxidase Chlorophyll fluorescence Drought Photoprotection Respiration Wheat |
dc.description.none.fl_txt_mv |
The aim of this study was to explore the role of the mitochondrial alternative oxidase (AOX) in the protection of photosynthesis during drought in wheat leaves. The relative water contents of water-replete and drought-exposed wheat plants were 97.2±0.3 and 75±2, respectively. Drought increased the amount of leaf AOX protein and also enhanced the rate of AOX-dependent O 2 uptake by the respiratory electron transport chain. The amount of the reduced, active form of the AOX protein was specifically increased by drought. The AOX inhibitor salicylhydroxamic acid (1 mM; SHAM) inhibited 70% of AOX activity in vivo in both water-replete and drought-exposed plants. Plants treated with SHAM were then exposed to low (100), high (350), or excess light (800 μmol photons m -2 s -1 ) for 90 min. SHAM did not modify chlorophyll a fluorescence quenching parameters in water-replete controls after any of these treatments. However, while the maximal quantum yield of photosystem II (PSII) electron transport (F v /F m ) was not affected by SHAM, the immediate quantum yield of PSII electron transport (Φ PSII ) and photochemical quenching (qP) were gradually reduced by increasing irradiance in SHAM-treated drought-exposed plants, the decrease being most pronounced at the highest irradiance. Non-photochemical quenching (NPO) reached near maximum levels in plants subjected to drought at high irradiance. However, a combination of drought and low light caused an intermediate increase in NPO, which attained higher values when AOX was inhibited. Taken together, these results show that up-regulation of the respiratory AOX pathway protects the photosynthetic electron transport chain from the harmful effects of excess light. Instituto de Fisiología Vegetal |
description |
The aim of this study was to explore the role of the mitochondrial alternative oxidase (AOX) in the protection of photosynthesis during drought in wheat leaves. The relative water contents of water-replete and drought-exposed wheat plants were 97.2±0.3 and 75±2, respectively. Drought increased the amount of leaf AOX protein and also enhanced the rate of AOX-dependent O 2 uptake by the respiratory electron transport chain. The amount of the reduced, active form of the AOX protein was specifically increased by drought. The AOX inhibitor salicylhydroxamic acid (1 mM; SHAM) inhibited 70% of AOX activity in vivo in both water-replete and drought-exposed plants. Plants treated with SHAM were then exposed to low (100), high (350), or excess light (800 μmol photons m -2 s -1 ) for 90 min. SHAM did not modify chlorophyll a fluorescence quenching parameters in water-replete controls after any of these treatments. However, while the maximal quantum yield of photosystem II (PSII) electron transport (F v /F m ) was not affected by SHAM, the immediate quantum yield of PSII electron transport (Φ PSII ) and photochemical quenching (qP) were gradually reduced by increasing irradiance in SHAM-treated drought-exposed plants, the decrease being most pronounced at the highest irradiance. Non-photochemical quenching (NPO) reached near maximum levels in plants subjected to drought at high irradiance. However, a combination of drought and low light caused an intermediate increase in NPO, which attained higher values when AOX was inhibited. Taken together, these results show that up-regulation of the respiratory AOX pathway protects the photosynthetic electron transport chain from the harmful effects of excess light. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 |
dc.type.none.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Articulo http://purl.org/coar/resource_type/c_6501 info:ar-repo/semantics/articulo |
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article |
status_str |
publishedVersion |
dc.identifier.none.fl_str_mv |
http://sedici.unlp.edu.ar/handle/10915/83404 |
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http://sedici.unlp.edu.ar/handle/10915/83404 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/issn/0022-0957 info:eu-repo/semantics/altIdentifier/doi/10.1093/jxb/eri111 |
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openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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