Aliphatic glucosinolate speciation in Arabidopsis thaliana moderates early bacterial colonization in a genotype-specific manner, regulating both consequences and benefits of colonization.

The plant influences early colonization of microbes e.g., by producing secondary metabolites, whereas some taxa found ways to overcome certain plant barriers. Still, little is understood about the factors and dynamics in early leaf colonization, even though it is utterly important for the establishment of the final microbial community. We used local Arabidopsis thaliana populations to isolate bacteria highly adapted to either of the A. thaliana genotypes. We characterized the isolated strains regarding their ability to colonize and cause disease on other A. thaliana genotypes as well as their susceptibility to glucosinolate-mediated plant defense. And we conducted whole-genome sequencing of some resistant isolates to identify potential resistance genes.