Involvement of the ABCG37 transporter in secretion of scopoletin and derivatives by Arabidopsis roots in response to iron deficiency

Authors

  • Pierre Fourcroy,

    1. Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, Montpellier Cedex 1, France
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    • These authors contributed equally to this work.
  • Patricia Sisó-Terraza,

    1. Department of Plant Nutrition, Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain
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    • These authors contributed equally to this work.
  • Damien Sudre,

    1. Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, Montpellier Cedex 1, France
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    • These authors contributed equally to this work.
  • María Savirón,

    1. New Organic Materials Unit, Institute of Materials Science of Aragón, CSIC-University of Zaragoza, Zaragoza, Spain
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  • Guilhem Reyt,

    1. Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, Montpellier Cedex 1, France
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  • Frédéric Gaymard,

    1. Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, Montpellier Cedex 1, France
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  • Anunciación Abadía,

    1. Department of Plant Nutrition, Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain
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  • Javier Abadia,

    1. Department of Plant Nutrition, Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain
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  • Ana Álvarez-Fernández,

    1. Department of Plant Nutrition, Estación Experimental de Aula Dei (CSIC), Zaragoza, Spain
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  • Jean-François Briat

    Corresponding author
    1. Biochimie et Physiologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université Montpellier 2, Montpellier Cedex 1, France
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Summary

  • Studies of Iron (Fe) uptake mechanisms by plant roots have focussed on Fe(III)-siderophores or Fe(II) transport systems. Iron deficency also enhances root secretion of flavins and phenolics. However, the nature of these compounds, their transport outside the roots and their role in Fe nutrition are largely unknown.
  • We used HPLC/ESI-MS (TOF) and HPLC/ESI-MS/MS (ion trap) to characterize fluorescent phenolic-type compounds accumulated in roots or exported to the culture medium of Arabidopsis plants in response to Fe deficiency. Wild-type and mutant plants altered either in phenylpropanoid biosynthesis or in the ABCG37 (PDR9) ABC transporter were grown under standard or Fe-deficient nutrition conditions and compared.
  • Fe deficiency upregulates the expression of genes encoding enzymes of the phenylpropanoid pathway and leads to the synthesis and secretion of phenolic compounds belonging to the coumarin family. The ABCG37 gene is also upregulated in response to Fe deficiency and coumarin export is impaired in pdr9 mutant plants.
  • Therefore it can be concluded that: Fe deficiency induces the secretion of coumarin compounds by Arabidopsis roots; the ABCG37 ABC transporter is required for this secretion to take place; and these compounds improved plant Fe nutrition.

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