biostudies-literatureUnknown27(3)Lauber EFrench National Research AgencyMolecular mechanisms underlying quantitative variations of pathogenicity remain elusive. Here, we identified the <i>Xanthomonas campestris</i> XopJ6 effector that triggers disease resistance in cauliflower and <i>Arabidopsis thaliana</i>. XopJ6 is a close homolog of the <i>Ralstonia</i><i>pseudo</i><i>solanacearum</i> PopP2 YopJ family acetyltransferase. XopJ6 is recognized by the RRS1-R/RPS4 NLR pair that integrates a WRKY decoy domain mimicking effector targets. We identified a XopJ6 natural variant carrying a single residue substitution in XopJ6 WRKY-binding site that disrupts interaction with WRKY proteins. This mutation allows XopJ6 to evade immune perception while retaining some XopJ6 virulence functions. Interestingly, <i>xopJ6</i> resides in a Tn<i>3</i>-family transposon likely coiScience109224https://www.ebi.ac.uk/biostudies/studies/S-EPMC10909901biostudies-literatureBacterial host adaptation through sequence and structural variations of a single type III effector gene.PMC10909901Noel LDVicedo CCarrere SPichereaux CLauber EEscouboue MGris CPouzet CJauneau ADeslandes LZhang ZMGonzalez-Fuente MLuneau JSfalseBacterial host adaptation through sequence and structural variations of a single type III effector gene.Molecular mechanisms underlying quantitative variations of pathogenicity remain elusive. Here, we identified the <i>Xanthomonas campestris</i> XopJ6 effector that triggers disease resistance in cauliflower and <i>Arabidopsis thaliana</i>. XopJ6 is a close homolog of the <i>Ralstonia</i><i>pseudo</i><i>solanacearum</i> PopP2 YopJ family acetyltransferase. XopJ6 is recognized by the RRS1-R/RPS4 NLR pair that integrates a WRKY decoy domain mimicking effector targets. We identified a XopJ6 natural variant carrying a single residue substitution in XopJ6 WRKY-binding site that disrupts interaction with WRKY proteins. This mutation allows XopJ6 to evade immune perception while retaining some XopJ6 virulence functions. Interestingly, <i>xopJ6</i> resides in a Tn<i>3</i>-family transposon likely co2024-01-01T00:00:00Z2024 Mar2026-07-15T00:10:23.56Z2025-04-19T22:02:56.936ZS-EPMC109099013843995410.1016/j.isci.2024.109224