Molecular requirements and effector targeting of the internalisation of pattern recognition receptors mediating plant immunity

Loiseau, Jenna (2019) Molecular requirements and effector targeting of the internalisation of pattern recognition receptors mediating plant immunity. Doctoral thesis, University of East Anglia.

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Abstract

In order to perceive pathogen-associated molecular pattern (PAMPs) derived from pathogenic microbes, plants express pattern recognition receptors (PRRs) at their cell surface, which mediate PAMP-triggered immunity (PTI). In Arabidopsis, bacterial PAMP flg22 perception undergoes internalisation of its cognate PRR FLAGELLIN-SENSING 2 (FLS2). Ligand-activated FLS2 follows the endocytic pathway through the late endosome/multivesicular bodies (LE /MVBs) compartments to the lytic vacuole for degradation. Advances have been made regarding our understanding of the subcellular trafficking of these receptors but the molecular mechanisms underlying the regulation of their trafficking and the interplay it has with immunity remain poorly understood. Recent data demonstrate that post translational modifications (PTM) regulate PRRs internalisation and is critical for the execution of immune responses. To better understand regulation of PRRs trafficking during immunity, I investigated regulation of PRRs subcellular trafficking upon PAMP perception by using a combination of live-cell imaging microscopy together with effector interference. Here, I present FLS2 traffics to the LE/MVBs via the trans-Golgi network (TGN)/early endosome (EE) and that this is dependent on the ADP RIBOSYLATION FACTOR GUANINE-NUCLEOTIDE EXCHANGE FACTOR (Arf-GEF) HopM1 interactor 7 (MIN7). Further, confirming that endocytosis is a common process among PRRs mediating immunity, I demonstrate that the Pseudomonas syringae effector HopM1 targets flg22-induced endocytosis of FLS2 and elf18-induced endocytosis of EFR at the TGN/EE but not constitutive endocytosis of BRI1. Additionally, I indicate that receptor activation is uncoupled from its internalisation.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Chris White
Date Deposited: 24 Jan 2020 10:00
Last Modified: 24 Jan 2020 10:00
URI: https://ueaeprints.uea.ac.uk/id/eprint/73776
DOI:

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