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Poster

Session: Session 2 Presenting Authors at Posters (Odds)

P-049 - Gluing bacteria and recruiting defense proteins: unraveling the mechanisms of apple amaranthin-like lectins in resistance to the fire blight pathogen, Erwinia amylovora

Wednesday, July 16, 2025
13:30 - 15:15  
Location: Confex Hall 3
Crop resistance genetics and genomics

    Presenting Author(s)

  • AF

    Axelle Frantz

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Beaucouzé, Pays de la Loir, FRANCE

    • Author(s)

  • MG

    Matthieu Gaucher

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • EV

    Emilie Vergne

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • AB

    Antoine Bodelot

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • MB

    Marie-Noëlle Brisset

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • CH

    Cyril Hamiaux

    The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, New Zealand
    Auckland, Auckland, New Zealand

  • EC

    Erwan Chavonet

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • TB

    Thierry Balliau

    GQE-UMR8120, Université Paris-Saclay, INRAE, CNRS, AgroParisTech, Gif-sur-Yvette, France
    Gif-sur-Yvettes, Ile-de-France, France

  • AR

    Aurélia Rolland

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

  • AD

    Alexandre Degrave

    IRHS-UMR1345, Université d’Angers, INRAE, Institut Agro, Angers, France
    Angers, Pays de la Loire, France

Erwinia amylovora (Ea) is responsible for fire blight, which devastates apple (Malus domestica) orchards. While the pathogenic factors of Ea are well characterized, the resistance mechanisms of apple trees remain less understood, hindering our comprehension of the molecular interactions between the two species. As part of an exploratory approach to uncover these mechanisms, we identified a class of apple proteins named Malus domestica AGGLUTININS (MdAGGs), whose accumulation provides enhanced resistance to fire blight. MdAGGs belong to the widely conserved amaranthin-like lectin family, soluble proteins with unknown function. Most plant amaranthin-like lectin genes encode chimeric proteins composed of amaranthin domains fused to typical defense protein domains. Intriguingly, apple MdAGG genes encode proteins that are only made of a single amaranthin domain, suggesting that interactions with other compounds are required to fulfill their defense activity. Using microscopy and pull-down assays, we provide evidence that MdAGGs respectively agglutinate Ea cells and interact with other plant defense proteins. Additional experiments are being conducted to determine whether and how these MdAGG-driven defense complexes contribute to bacterial clearance in planta, potentially revealing a novel defense mechanism.