Edinburgh, Scotland, United Kingdom - TAIR

Deciphering PAMP-triggered immunity in
Arabidopsis
In plant innate immunity, the first line of microbial recognition relies on the
perception of pathogen-associated molecular patterns (PAMPs) by patternrecognition
receptors (PRRs) leading to PAMP-triggered immunity (PTI). In
Arabidopsis, the leucine-rich repeat receptor kinases EFR and FLS2, in
association with BAK1, mediate recognition of the bacterial PAMPs EF-Tu and
flagellin, or their peptide surrogates elf18 and flg22 respectively. Despite the
critical role of PRRs in anti-microbial immunity, only limited knowledge exists on
how they function at the molecular level and on their downstream signalling
events. By forward genetics, we have identified 160 elf18-insensitive (elfin)
mutants; 57 corresponding to efr mutants. The identification and characterisation
of six ELFIN genes shed light on how EFR protein expression is controlled, as
well as on immediate downstream signalling. We describe an unexpected subspecialisation
of the ER quality control (ER-QC) machinery for innate immunity,
and the first demonstration of a physiological role of the ER-QC in transmembrane
receptor function in plants. In addition, we identified a new bak1 allele
that impacts differentially the requirement of BAK1 in PTI and brassinosteroid
signalling. We are using a combination of genetic, cell biology and biochemistry
to unravel the molecular mechanisms underlying this puzzling phenotype. This
study should reveal how BAK1 interacts with different signalling pathways in
plants. Our quest to decipher PTI signalling is complemented by the search and
characterisation of EFR-interacting proteins (EIPs) in yeast and in planta. We
are also describing the feasibility of trans-family heterologous expression of
PRRs to engineer broad-spectrum disease resistance in plants.
37
L12
Thursday 12:00 - 12:30
Plant Defence
Cyril Zipfel
The Sainsbury Laboratory
Norwich Research Park
Norwich
NR4 7UH
UK