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Poster

Session: Session 2 Presenting Authors at Posters (Evens)

P-420 - Natural variation at a signaling hub links immune signaling with environment

Thursday, July 17, 2025
13:30 - 15:15  
Location: Confex Hall 3
Plant Regulation of biotic and abiotic stress – trade-offs

    Presenting Author(s)

  • IW

    Isabel Wünsche

    PhD candidate
    Leibniz Institute of Plant Biochemistry - Halle
    Halle, Sachsen-Anhalt, Germany

    • Author(s)

  • SL

    Sarah Lederer

    Postdoc
    Leibniz Institute of Plant Biochemistry - Halle
    Halle, Sachsen-Anhalt, Germany

  • SM

    Susanne Matschi

    Postdoc
    Leibniz-Institute of Plant Biochemistry
    Halle, Sachsen-Anhalt, Germany

  • JO

    Jan Oehlschläger

    PhD candidate
    Leibniz-Institute for Plant biochemistry (IPB)
    Halle, Sachsen-Anhalt, Germany

  • WH

    Wolfgang Hoehenwarter

    Postdoc
    Department of Pharmaceutical Chemistry and Bioanalytics, Martin-Luther-University Halle-Wittenberg
    Halle, Sachsen-Anhalt, Germany

  • AS

    Andrea Sinz

    Professor
    Department of Pharmaceutical Chemistry and Bioanalytics, Martin-Luther-University Halle-Wittenberg
    Halle, Sachsen-Anhalt, Germany

  • TR

    Tina Romeis

    Department Leader
    Leibniz-Institute of Plant Biochemistry
    Halle (Saale), Sachsen-Anhalt, Germany

Calcium-dependent protein kinase CPK5 is a key regulator of local and systemic plant immune signaling, and its contribution to defense signal propagation - via synergistic phosphorylation of RBOHD at the plasma membrane - is known.  Interestingly, natural variation, especially non-synonymous single nucleotide polymorphisms (nsSNPs) causing amino acid exchanges, of CPK5 is restricted to the intrinsically disordered variable domain at the N-terminus. There, no direct biochemical calcium-dependent activation and/or phosphorylation involving the internal kinase or calcium binding domains is affected. We thus hypothesize that the CPK5 haplotypes that are collected from warm-temperature climate zones may alter the accessibility toward its phosphorylation substrate that is required for biotic stress signaling. We assessed the different CPK5 proteoforms for the kinase and RBOHD protein-protein interaction (BiFC), RBOHD substrate phosphorylation, and investigate kinase and substrate 3D structural information using cross-linking mass-spectrometry. In particular, the structural approach deciphers how single amino acid substitutions may affect protein structure at the interaction surface between CPK5 and RBOHD. Taken together, our data suggests that natural variation of a key signaling component provides an evolutionary mechanism that fine-tunes immune signaling in distinct environmental conditions.