Skip to main content
ISMPMI Congress 2025 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.

Poster

Session: Session 1 Presenting Authors at Posters (Odds)

P-019 - Conservation of an Immune Homeostasis Module in Land Plants

Monday, July 14, 2025
13:30 - 15:15  
Location: Confex Hall 3
Extracellular & Intracellular non-self recognition & signaling

    Presenting Author(s)

  • RD

    Ruoqi Dou

    Queen's University
    Kingston, Ontario, Canada

    • Author(s)

  • KM

    Karima El Mahboubi

    Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS, UPS
    Toulouse, Midi-Pyrenees, France

  • CT

    Cailun A.S. Tanney

    Queen's University
    kingston, Ontario, Canada

  • JC

    Jiashu Chu

    Institute of Plant and Microbial Biology and Zurich-Basel Plant Science Center, University of Zurich
    Zurich, Zurich, Switzerland

  • BC

    Baptiste Castel

    CNRS
    Castanet Tolosan, Midi-Pyrenees, France

  • MB

    Melissa Bredow

    Department of Plant Pathology, Entomology and Microbiology, Iowa State University
    Ames, Iowa, United States

  • MR

    Maria Camila Rodriguez-Gallo

    University of Alberta
    Edmonton, Alberta, Canada

  • VM

    Virginia-Natali Miguel

    Queen's University
    Kingston, Ontario, Canada

  • DL

    Dominique Lauressergues

    Laboratoire de Recherche en Sciences Végétales (LRSV), Université de Toulouse, CNRS
    Toulouse, Midi-Pyrenees, France

  • JK

    Jean Keller

    CNRS
    Castanet-Tolosan, Midi-Pyrenees, France

  • TD

    Thomas A. DeFalco

    Assistant professor
    Department of Biology, Western University
    London, Ontario, Canada

  • RU

    R. Glen Uhrig

    Professor
    University of Alberta
    Edmonton, Alberta, Canada

  • CZ

    Cyril Zipfel

    Institute of Plant and Microbial Biology, University of Zurich / The Sainsbury Laboratory
    Zurich, Zurich, Switzerland

  • PD

    Pierre-Marc Delaux

    CNRS
    Castanet-Tolosan, Midi-Pyrenees, France

  • JM

    Jacqueline Monaghan

    Queen's University
    Kingston, Ontario, Canada

Immune homeostasis is critical for plant survival, ensuring an optimal balance between pathogen defense and growth. In Arabidopsis thaliana, CALCIUM-DEPENDENT PROTEIN KINASE 28 (CPK28) regulates immune signaling by phosphorylating the E3 ubiquitin ligases PLANT U-BOX 25 (PUB25) and PUB26, which mediate turnover of BOTRYTIS-INDUCED KINASE 1 (BIK1), a key immune signaling hub. BIK1 stability is also redundantly controlled by PUB22, PUB23, and PUB24, forming a robust regulatory network that prevents excessive immune activation. However, whether this immune regulatory module is conserved across land plants remains unclear. Here, we identify and characterize a homologous CPK28-PUB-BIK1 module in the liverwort Marchantia polymorpha. We show that MpCPK28 phosphorylates and interacts with MpPUB20e, a putative ortholog of AtPUB25/26, and MpPBLa, a functional equivalent of AtBIK1. MpPBLa undergoes proteasomal degradation and is ubiquitinated by MpPUB20e in vitro, mirroring PUB25/26 function. Overexpression of MpCPK28 in Marchantia causes developmental abnormalities and reduced chitin-induced ROS, resembling AtCPK28 overexpression. Complementation assays confirm functional conservation, as MpCPK28 rescues the immune and developmental defects of Arabidopsis cpk28-1 mutants. These findings indicate that the CPK28-PUB-BIK1 module is an ancient mechanism of immune homeostasis in land plants. I will present ongoing work aimed at strengthening this hypothesis.