P-375 - Molecular and cellular dynamics of rice immune receptors

Monday, July 14, 2025

13:30 - 15:15

Location: Confex Hall 3

Subcellular dynamics and signaling in host-microbe interactions

Presenting Author(s)

LC

Lila Cadiou

PhD student
Plant Health Institute of Montpellier, Univ Montpellier, INRAE, CIRAD, Institut Agro, IRD, Montpellier, France
Montpellier, Languedoc-Roussillon, France

Author(s)

CC

Caroline Clerté

Centre de Biologie Structurale, Montpellier, Univ Montpellier, CNRS UMR 5048, INSERM U 1054, Montpellier, France
Montpellier, Languedoc-Roussillon, France
EM

Emmanuel Margeat

Centre de Biologie Structurale, Montpellier, Univ Montpellier, CNRS UMR 5048, INSERM U 1054, Montpellier, France
Montpellier, Languedoc-Roussillon, France
ND

Nathalie Declerck

Centre de Biologie Structurale, Montpellier, Univ Montpellier, CNRS UMR 5048, INSERM U 1054, Montpellier, France
Montpellier, Languedoc-Roussillon, France
TK

Thomas Kroj

Plant Health Institute of Montpellier
Montpellier, Languedoc-Roussillon, France

Nucleotide-binding and leucine-rich repeat proteins (NLRs) are a dominant class of plant immune receptors. In certain cases, two different NLRs cooperate in the activation of immunity: one that is called sensor or sNLR recognizes the signals from the pathogen, and the other that is named helper or hNLR induces signalling.
The hNLR/sNLR pair RGA4/RGA5 from rice (Oryza sativa), which detects the effectors AVR-Pia and AVR1-CO39 from the blast fungus Magnaporthe oryzae, is a model system for the understanding of NLR pairs. RGA4 is an auto-active inducer of cell-death and is, in the absence of the fungus, repressed by RGA5 by the formation of an inactive RGA4/RGA5 hetero-complex. Upon M. oryzae infection, RGA5 binds the effectors through its non-canonical integrated heavy metal associated (HMA) domain and repression on RGA4 is lifted. However, it is not known, how this binding event leads to immune activation.
In my PhD project, I developed cell biological approaches to decipher the cellular dynamics of RGA4 and RGA5 function. I will present findings that suggest re-localization of RGA4 upon effector detection by RGA5 and preliminary results on the application of fluorescence technics such as Fluorescence Correlation Spectroscopy (FCS) to observe dynamics of protein interactions in living cells. These techniques were developed in animal and bacterial cells, but have not yet or only rarely been applied to plant systems.