Fig. 5: The shoot-derived antibacterial compound is host-genotype specific.

a Competition assays, as described in Fig. 3, between wild-type Paraburkholderia bryophila MF376 (WT) and a deletion mutant in the shoot association ef90 efflux pump (d90) growing in a 1:1 mix of medium and macerated leaf extract of diverse plant host species (a; phylogenetic tree) or different Arabidopsis thaliana accessions (b). Each plant host was tested in two competition assays: chloramphenicol-resistant wild type, Chl^R WT, against Tetracycline-resistant mutant, Tet^R d90 (left), and the reciprocal competition Chl^R d90 against Tet^R WT (right). Competition results were measured by plating 1:1000 diluted overnight cultures on agar plates containing differentiating antibiotics. Only Arabidopsis thaliana Col-0 accession inhibited the mutant’s growth.