The bacterial biocontrol agent Paenibacillus alvei K165 confers inherited resistance against Verticillium dahliae.

The biocontrol agent Paenibacillus alvei K165 was previously shown to protect Arabidopsis thaliana plants against Verticillium dahliae. Here we show that K165 also confers inherited immune resistance against V. dahliae. By performing a histone acetyltransferases mutant screen, ChIP-assays and transcriptomic experiments we were able to show that histone acetylation significantly contributes to the K165 biocontrol activity and establishment of inheritable resistance against V. dahliae. K165 treatment primed the expression of immune-related marker genes and the cinnamyl alcohol dehydrogenases CAD3 through the function of histone acetyltransferases. Our results reveal that offspring of plants treated with K165 have primed immunity and enhanced lignification both contributing towards the K165-mediated inherited immune resistance. Thus, our study paves that way for the use of biocontrol agents for the establishment of inheritable resistance against agronomically important pathogens.