The quorum sensing molecule 2'-aminoacetophenone activates plant cell-surface immune receptors

Quorum sensing (QS) enhances bacterial pathogenesis. How plants perceive QS signals remains elusive. Here, we report that Arabidopsis thaliana perceives 2'-aminoacetophenone (2’-AA), a QS-regulated volatile compound emitted from Pseudomonas aeruginosa, through cell-surface pattern recognition receptor (PRR) complexes that require BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED KINASE (BAK1). 2’-AA activates PRR-mediated immunity and enhances plant resistance to Pseudomonas pathogens. The 2’-AA-activated immunity displayed structural specificity of the elicitor and genetic specificity of the PRR complexes. 2’-AA induces in vivo protein interactions between BAK1 and its co-functioning PPRs, meanwhile the plant transcriptome responded to 2’-AA similarly as to flg22, a bacterial immunogenic elicitor that activates BAK1-dependent immunity. Hence bacterial QS signals can be sensed by plant cell-surface immune receptors. Examination of 3 different samples of Col-0, each of samples contains 3 biological replicates. They are named as mock, flg22 and 2'-AA respectively..