Updated project metadata. During Agrobacterium rhizogenes–plant interaction, the rolB gene is transferred into the plant genome and is stably inherited in the plant’s offspring. Among the numerous effects of rolB on plant metabolism, including the activation of secondary metabolism, its effect on plant defense systems has not been sufficiently studied. Here, we performed a proteomic analysis of rolB-expressing Arabidopsis plants with a particular focus on defense proteins. In rolB plants, a reduced amount of scaffold proteins RACK1A, RACK1B, and RACK1C, known as receptors for activated C-kinase 1, was found. Proteomic analysis showed that rolB could potentially suppress the plant immune system by suppressing the RNA-binding proteins GRP7, CP29B, and CP31B, similar to the action of type III bacterial effectors. At the same time, rolB plants induce massive biosynthesis of protective proteins VSP1, VSP2, and PR4, which are markers of the activated jasmonate pathway. Moreover, rolB plants activate all components of the PYK10 defense complex of the endoplasmic reticulum involved in the metabolism of glucosinolates. We hypothesized that various defense systems activated by rolB are aimed at protecting the host plant from competing phytopathogens in order to create an effective ecological niche for A. rhizogenes. A RolB → RACK1A signaling module has been proposed that can exert most of the rolB-mediated effects on plant physiology and biochemistry.