A root-knot nematode-secreted protein is injected into giant cells and targeted to the nuclei

Authors

  • Maëlle Jaouannet,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Laetitia Perfus-Barbeoch,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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    • Both authors contributed equally to this work.

  • Emeline Deleury,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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    • Both authors contributed equally to this work.

  • Marc Magliano,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Gilbert Engler,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Paulo Vieira,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Etienne G. J. Danchin,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Martine Da Rocha,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Patrick Coquillard,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Pierre Abad,

    1. INRA UMR 1301, CNRS UMR 6243, Université de Nice Sophia Antipolis, 400 route des Chappes, F-06903 Sophia-Antipolis, France
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  • Marie-Noëlle Rosso

    1. INRA, Université Aix-Marseille, UMR1163 Biotechnologie des Champignons Filamenteux, F-13288 Marseille, France
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Author for correspondence:
Pierre Abad
Tel: +33 492 386 402
Email: pierre.abad@sophia.inra.fr

Summary

  • Root-knot nematodes (RKNs) are obligate endoparasites that maintain a biotrophic relationship with their hosts over a period of several weeks and induce the differentiation of root cells into specialized feeding cells. Nematode effectors synthesized in the oesophageal glands and injected into the plant tissue through the syringe-like stylet certainly play a central role in these processes.
  • In a search for nematode effectors, we used comparative genomics on expressed sequence tag (EST) datasets to identify Meloidogyne incognita genes encoding proteins potentially secreted upon the early steps of infection.
  • We identified three genes specifically expressed in the oesophageal glands of parasitic juveniles that encode predicted secreted proteins. One of these genes, Mi-EFF1 is a pioneer gene that has no similarity in databases and a predicted nuclear localization signal. We demonstrate that RKNs secrete Mi-EFF1 within the feeding site and show Mi-EFF1 targeting to the nuclei of the feeding cells.
  • RKNs were previously shown to secrete proteins in the apoplasm of infected tissues. Our results show that nematodes sedentarily established at the feeding site also deliver proteins within plant cells through their stylet. The protein Mi-EFF1 injected within the feeding cells is targeted at the nuclei where it may manipulate nuclear functions of the host cell.

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