Genetic Dissection of the Interaction Between the Plant Pathogen Xanthomonas campestris pv. vesicatoria and Its Host Plants

Abstract

The interaction between the plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv)∈dexXanthomonas campestris pv. vesicatoria (Xcv) and its host plants pepper and tomato depends on a type III protein secretion system (T3SS)∈dextype III protein secretion system (T3SS) which translocates effector proteins into the plant cell. Recent studies revealed that HpaB and HpaC are two key players in the control of protein export from Xcv. First identified by their avirulence activity in resistant plants, genome sequencing projects allow now the identification of more effector proteins. However, their virulence functions in the host remain elusive. The effector AvrBs3 from Xcv induces a hypertrophy in susceptible plants. The virulence as well as the avirulence activity of AvrBs3 depends on its eukaryotic features, i.e., nuclear localization signals and an activation domain suggesting that the effector mimics a plant transcriptional regulator. Here, we present recent progress on the identification of potential virulence targets of AvrBs3 in the plant cell.