The Arabidopsis vacuolar anion transporter, AtCLCc, is involved in the regulation of stomatal movements and contributes to salt tolerance

Authors

  • Mathieu Jossier,

    1. Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
    2. Université Paris 7 Denis Diderot, Unité de Formation et de Recherche Sciences du Vivant, 35 rue Hélène Brion, 75205 Paris Cedex 13, France
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    • These authors contributed equally to this work.

  • Laëtitia Kroniewicz,

    1. Laboratoire des Echanges Membranaires et Signalisation, Unité Mixte de Recherche 6191, Centre National de la Recherche Scientifique/Commissariat à l’Energie Atomique, Université Aix-Marseille II, Commissariat à l’Energie Atomique Cadarache Batiment 156, 13108 St Paul-lez-Durance, France
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    • These authors contributed equally to this work.

  • Fabien Dalmas,

    1. Laboratoire des Echanges Membranaires et Signalisation, Unité Mixte de Recherche 6191, Centre National de la Recherche Scientifique/Commissariat à l’Energie Atomique, Université Aix-Marseille II, Commissariat à l’Energie Atomique Cadarache Batiment 156, 13108 St Paul-lez-Durance, France
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  • D. Le Thiec,

    1. Institut National de la Recherche Agronomique, Nancy Université, Unité Mixte de Recherche1137 Ecologie et Ecophysiologie Forestières, Institut Fédératif de Recherche 110, EFABA, F-54280 Champenoux, France
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  • Geneviève Ephritikhine,

    1. Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
    2. Université Paris 7 Denis Diderot, Unité de Formation et de Recherche Sciences du Vivant, 35 rue Hélène Brion, 75205 Paris Cedex 13, France
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  • Sébastien Thomine,

    1. Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
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  • Hélène Barbier-Brygoo,

    1. Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
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  • Alain Vavasseur,

    1. Laboratoire des Echanges Membranaires et Signalisation, Unité Mixte de Recherche 6191, Centre National de la Recherche Scientifique/Commissariat à l’Energie Atomique, Université Aix-Marseille II, Commissariat à l’Energie Atomique Cadarache Batiment 156, 13108 St Paul-lez-Durance, France
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  • Sophie Filleur,

    Corresponding author
    1. Institut des Sciences du Végétal, Centre National de la Recherche Scientifique, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France
    2. Université Paris 7 Denis Diderot, Unité de Formation et de Recherche Sciences du Vivant, 35 rue Hélène Brion, 75205 Paris Cedex 13, France
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  • Nahalie Leonhardt

    Corresponding author
    1. Laboratoire des Echanges Membranaires et Signalisation, Unité Mixte de Recherche 6191, Centre National de la Recherche Scientifique/Commissariat à l’Energie Atomique, Université Aix-Marseille II, Commissariat à l’Energie Atomique Cadarache Batiment 156, 13108 St Paul-lez-Durance, France
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(fax +33 1 69 82 37 68; e-mail filleur@isv.cnrs-gif.fr or fax +33 4 42 25 23 64; e-mail nathalie.leonhardt@cea.fr).

Summary

In plant cells, anion channels and transporters are essential for key functions such as nutrition, resistance to biotic or abiotic stresses, and ion homeostasis. In Arabidopsis, members of the chloride channel (CLC) family located in intracellular organelles have been shown to be required for nitrate homeostasis or pH adjustment, and previous results indicated that AtCLCc is involved in nitrate accumulation. We investigated new physiological functions of this CLC member in Arabidopsis. Here we report that AtCLCc is strongly expressed in guard cells and pollen and more weakly in roots. Use of an AtCLCc:GFP fusion revealed localization to the tonoplast. Disruption of the AtCLCc gene by a T-DNA insertion in four independent lines affected physiological responses that are directly related to the movement of chloride across the tonoplast membrane. Opening of clcc stomata was reduced in response to light, and ABA treatment failed to induce their closure, whereas application of KNO3 but not KCl restored stomatal opening. clcc mutant plants were hypersensitive to NaCl treatment when grown on soil, and to NaCl and KCl in vitro, confirming the chloride dependence of the phenotype. These phenotypes were associated with modifications of chloride content in both guard cells and roots. These data demonstrate that AtCLCc is essential for stomatal movement and salt tolerance by regulating chloride homeostasis.

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