Arabidopsis A BOUT DE SOUFFLE is a putative mitochondrial transporter involved in photorespiratory metabolism and is required for meristem growth at ambient CO2 levels

Authors

  • Marion Eisenhut,

    1. Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
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    • These authors contributed equally to this work.

  • Severine Planchais,

    1. Physiologie Moléculaire et Cellulaire des Plantes Université Pierre et Marie Curie Paris 6, Centre National de la Recherche Scientifique, Paris, France
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    • These authors contributed equally to this work.

  • Cécile Cabassa,

    1. Physiologie Moléculaire et Cellulaire des Plantes Université Pierre et Marie Curie Paris 6, Centre National de la Recherche Scientifique, Paris, France
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  • Anne Guivarc'h,

    1. Physiologie Moléculaire et Cellulaire des Plantes Université Pierre et Marie Curie Paris 6, Centre National de la Recherche Scientifique, Paris, France
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  • Anne-Marie Justin,

    1. Physiologie Moléculaire et Cellulaire des Plantes Université Pierre et Marie Curie Paris 6, Centre National de la Recherche Scientifique, Paris, France
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  • Ludivine Taconnat,

    1. Department of Plant Genomics Research, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique, 91057 Evry, France
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  • Jean-Pierre Renou,

    1. Department of Plant Genomics Research, Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique, 91057 Evry, France
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  • Marc Linka,

    1. Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
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  • David Gagneul,

    1. Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
    Current affiliation:
    1. Université Lille, Sciences et Technologies, Villeneuve d'Ascq Cedex, France
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  • Stefan Timm,

    1. Universität Rostock, Institut für Biowissenschaften Abteilung Pflanzenphysiologie Albert-Einstein-Strasse 3, Rostock, Germany
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  • Hermann Bauwe,

    1. Universität Rostock, Institut für Biowissenschaften Abteilung Pflanzenphysiologie Albert-Einstein-Strasse 3, Rostock, Germany
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  • Pierre Carol,

    Corresponding author
    • Physiologie Moléculaire et Cellulaire des Plantes Université Pierre et Marie Curie Paris 6, Centre National de la Recherche Scientifique, Paris, France
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  • Andreas P.M. Weber

    Corresponding author
    • Institut für Biochemie der Pflanzen, Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany
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For correspondence (e-mails pierre.carol@upmc.fr or andreas.weber@uni-duesseldorf.de).

Summary

Photorespiratory metabolism is essential in all oxygenic photosynthetic organisms. In plants, it is a highly compartmentalized pathway that involves chloroplasts, peroxisomes, mitochondria and the cytoplasm. The metabolic pathway itself is well characterized, and the enzymes required for its function have been identified. However, very little information is available on the transport proteins that catalyze the high metabolic flux between the involved compartments. Here we show that the A BOUT DE SOUFFLE (BOU) gene, which encodes a mitochondrial carrier, is involved in photorespiration in Arabidopsis. BOU was found to be co-expressed with photorespiratory genes in leaf tissues. The knockout mutant bou-2 showed the hallmarks of a photorespiratory growth phenotype, an elevated CO2 compensation point, and excessive accumulation of glycine. Furthermore, degradation of the P-protein, a subunit of glycine decarboxylase, was demonstrated for bou-2, and is reflected in strongly reduced glycine decarboxylase activity. The photorespiration defect in bou-2 has dramatic consequences early in the seedling stage, which are highlighted by transcriptome studies. In bou-2 seedlings, as in shm1, another photorespiratory mutant, the shoot apical meristem organization is severely compromised. Cell divisions are arrested, leading to growth arrest at ambient CO2. Although the specific substrate for the BOU transporter protein remains elusive, we show that it is essential for the function of the photorespiratory metabolism. We hypothesize that BOU function is linked with glycine decarboxylase activity, and is required for normal apical meristems functioning in seedlings.

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