A functional link between Enhanced Disease Susceptibility 1 and GH3.12/avrPphB susceptible 3 in pattern-triggered immunity in plants

Pattern recognition receptors (PRRs) recognize microbial molecular patterns to enhance plant defenses through pattern-triggered immunity (PTI). In Arabidopsis, EFR and FLS2 provide PRRs for bacterial EF-Tu (elf18 epitope) and flagellin (flg22 epitope), respectively. Whether and how PRRs are diverged in defense signaling downstream of receptor complexes is unknown. Here we report that ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) is required for EFR- but not FLS2-mediated immunity against Pseudomonas syringae pv. tomato DC3000. Genome-wide profiling of elf18-induced transcriptional reprograming reveals defense-related genes that are deregulated in eds1 plants and rsw3, a dysfunctional glucosidase II± allele, which is specifically impaired in elf18-induced sustained defense activation. Negatively influenced elf18-inducible genes in eds1 and rsw3 plants include PBS3, encoding GH3 acyl adenylase. PBS3 also identifies a critical component in EFR-triggered immunity. Our findings point to a critical role for EDS1-mediated PBS3 induction in PTI and separate requirements between the EFR and FLS2 pathways. Three plant genotypes, three treatments including the control, and four time points were tested. For each condition, three biological replicates were made.