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Poster

Session: Session 1 Presenting Authors at Posters (Evens)

P-054 - Maize signaling peptides in immunity and cell death

Tuesday, July 15, 2025
09:55 - 11:30  
Location: Confex Hall 3
Extracellular & Intracellular non-self recognition & signaling

    Presenting Author(s)

  • MK

    Maurice Koenig

    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

    • Author(s)

  • SB

    Sina Barghan

    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

  • PK

    Philipp Katzy

    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

  • JM

    Johana Misas Villamil

    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

  • GD

    Gunther Doehlemann

    Professor
    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

  • ZS

    Zarah Sorger

    PhD Candidate
    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

  • ES

    Eric Schmelz

    University of California, San Diego
    San Diego, California, United States

  • SS

    Simon Stael

    Upsalla University
    Uppsala, Uppsala Lan, Sweden

  • LM

    Lukas Meschig

    University of Cologne
    Cologne, Nordrhein-Westfalen, Germany

Phytocytokines are vital signaling molecules that regulate plant development, immunity, and stress responses. They are rapidly transcribed and released upon stimuli, alerting bystander cells.
Our research demonstrates that phytocytokines and microbe-associated molecular patterns (MAMPs) trigger distinct immune responses, despite activating similar pathways. Maize phytocytokines, such as Zea mays immune peptide 1 (Zip1), typically do not induce cell death after tissue damage, unlike microbial signals. Zip1 activates salicylic acid (SA)-mediated responses, including pathogenesis-related (PR) gene expression and papain-like cysteine protease (PLCP) activation. We discovered that the Zip1 precursor, PROZIP1, is localized to the microsome and cytoplasm, requiring specific processing for release. We identified MC9, a calcium-dependent metacaspase, that processes PROZIP1 through arginine-dependent cleavage. Removal of the PROZIP1 N-terminal domain is needed for its translocation to the apoplast via exocytosis. A peptidomics screen revealed novel SA-related peptides, with one acting as a susceptibility factor in Ustilago maydis infection without causing cell death, while another induces cell death in pathogen interactions. These phytocytokines differentially regulate hormonal pathways, influencing survival or cell-death decisions. Understanding the release mechanisms of phytocytokines, using Zip1 as a model, will enhance our knowledge of their role in regulating cell fate.