Virulence mechanisms and host specificity of gall-forming Pantoea agglomerans.
Pantoea agglomerans has been transformed from a commensal bacterium associated with many plants into a host-specific gall-forming pathogen by acquiring a plasmid-borne pathogenicity island. This pathogenicity island harbors the hrp/hrc gene cluster, in addition to genes encoding type III effector proteins, biosynthesis of the phytohormones indole-3-acetic acid and cytokinin, multiple diverse insertion sequences and pseudogenes. This review describes a unique model for understanding the emergence of new pathogens or new pathogenic variants, offering an insight into the function of type III effectors in host specificity and the evolution of a pathogen into pathovars. It also addresses the primary role of type III effectors in gall initiation as compared with a secondary role of phytohormones secreted by the pathogen.
Barash
Isaac
I
Department of Plant Sciences, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel. isaaci@post.tau.ac.il
Manulis-Sasson
Shulamit
S
D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D044404:Genomic Islands; D054884:Host-Pathogen Interactions; D020636:Pantoea / Q000235:genetics* / Q000472:pathogenicity*; D010941:Plant Tumors; D010957:Plasmids / Q000235:genetics; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000633:toxicity
D037521:Virulence Factors