Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions

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 a...

Descripción completa

Detalles Bibliográficos
Autores principales: Bartoli, Carlos Guillermo, Gomez, Facundo Martin, Gergoff, Gustavo, Guiamet, Juan José, Puntarulo, Susana
Formato: Articulo
Lenguaje:Inglés
Publicado: 2005
Materias:
Ciencias Naturales
Alternative oxidase
Chlorophyll fluorescence
Drought
Photoprotection
Respiration
Wheat
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83404
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83404
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
Alternative oxidase
Chlorophyll fluorescence
Drought
Photoprotection
Respiration
Wheat
spellingShingle Ciencias Naturales
Alternative oxidase
Chlorophyll fluorescence
Drought
Photoprotection
Respiration
Wheat
Bartoli, Carlos Guillermo
Gomez, Facundo Martin
Gergoff, Gustavo
Guiamet, Juan José
Puntarulo, Susana
Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions
topic_facet Ciencias Naturales
Alternative oxidase
Chlorophyll fluorescence
Drought
Photoprotection
Respiration
Wheat
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.
format Articulo
Articulo
author Bartoli, Carlos Guillermo
Gomez, Facundo Martin
Gergoff, Gustavo
Guiamet, Juan José
Puntarulo, Susana
author_facet Bartoli, Carlos Guillermo
Gomez, Facundo Martin
Gergoff, Gustavo
Guiamet, Juan José
Puntarulo, Susana
author_sort Bartoli, Carlos Guillermo
title Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions
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
publishDate 2005
url http://sedici.unlp.edu.ar/handle/10915/83404
work_keys_str_mv AT bartolicarlosguillermo upregulationofthemitochondrialalternativeoxidasepathwayenhancesphotosyntheticelectrontransportunderdroughtconditions
AT gomezfacundomartin upregulationofthemitochondrialalternativeoxidasepathwayenhancesphotosyntheticelectrontransportunderdroughtconditions
AT gergoffgustavo upregulationofthemitochondrialalternativeoxidasepathwayenhancesphotosyntheticelectrontransportunderdroughtconditions
AT guiametjuanjose upregulationofthemitochondrialalternativeoxidasepathwayenhancesphotosyntheticelectrontransportunderdroughtconditions
AT puntarulosusana upregulationofthemitochondrialalternativeoxidasepathwayenhancesphotosyntheticelectrontransportunderdroughtconditions
bdutipo_str Repositorios
_version_ 1764820488579710982

Ejemplares similares