Chitin perception in plasmodesmata characterises submembrane immune signalling specificity in plants (2020)

Cheval C*, Samwald S*, Johnston MG*, de Keijzer J, Breakspear A, Liu X, Bellandi A, Kadota Y, Zipfel C, Faulkner C
*These authors contributed equally to this work.

PNAS 117(17):9621-29 10.1073/pnas.1907799117 Download

Abstract

The plasma membrane (PM) is composed of heterogeneous subdomains, characterised by differences in protein and lipid composition. PM receptors can be dynamically sorted into membrane domains to underpin signalling in responses to extracellular stimuli. In plants, the plasmodesmal PM is a discrete microdomain that hosts specific receptors and responses. We exploited the independence of this PM domain to investigate how membrane domains can independently integrate a signal that triggers responses across the cell. Focusing on chitin signalling, we found that responses in the plasmodesmal PM require the LysM receptor kinases LYK4 and LYK5 in addition to LYM2. Chitin induces dynamic changes in the localisation, association or mobility of these receptors but only LYM2 and LYK4 are detected in the plasmodesmal PM. We further uncovered that chitin-induced production of reactive oxygen species and callose depends on specific signalling events that lead to plasmodesmata closure. Our results demonstrate that distinct membrane domains can integrate a common signal with specific machinery that initiates discrete signalling cascades to produce a localised response.

Originally a preprint.

Published on April 28, 2020