Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogenPseudomonas syringaepathovar phaseolicola

• DOI: 10.1073/pnas.96.19.10875
• Publication Date: 2002-07-26T14:32:33Z
• Authors: Robert W. Jackson; Evangelos Athanas...; George Tsiamis; John W. Mansfield; Ane Sesma; Dawn L. Arnold; Marjorie J. Gibbon; Jesus Murillo; John D. Taylor; Alan Vivian
• Keywords: Pathovar; Pseudomonas syringae; Pathogenicity island; Pseudomonadales

The 154-kb plasmid was cured from race 7 strain 1449B of the phytopathogen Pseudomonas syringae pv. phaseolicola ( Pph ). Cured strains lost virulence toward bean, causing hypersensitive reaction in previously susceptible cultivars. Restoration achieved by complementation with cosmid clones spanning a 30-kb region that contained identified avirulence avr ) genes avrD , avrPphC and avrPphF . Single transposon insertions at multiple sites (including one located abolished restoration genomic clones. Sequencing 11 kb complementing three potential vir were predicted to encode hydrophilic proteins shared hrp -box promoter motif indicating regulation HrpL. One gene partial when cloned on its own therefore designated virPphA as first A be for function. In soybean, acted an controlling expression rapid cultivar-specific reaction. also revealed presence homologs insertion sequence IS 100 Yersinia transposase Tn 501 P. aeruginosa proximity several together mobile elements, well G+C content significantly lower than expected indicates we have plasmid-borne pathogenicity island equivalent those found mammalian pathogens.