This Article Full Text Full Text (PDF) Supplemental material Other Versions of this Article: AEM.01511-07v1 73/23/7552    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Weinthal, D. M. Articles by Manulis-Sasson, S. Search for Related Content PubMed PubMed Citation Articles by Weinthal, D. M. Articles by Manulis-Sasson, S. Agricola Articles by Weinthal, D. M. Articles by Manulis-Sasson, S.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, December 2007, p. 7552-7561, Vol. 73, No. 23
0099-2240/07/$08.00+0     doi:10.1128/AEM.01511-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Distribution and Replication of the Pathogenicity Plasmid pPATH in Diverse Populations of the Gall-Forming Bacterium Pantoea agglomerans ^{, ,}

Department of Plant Pathology and Weed Research, ARO, The Volcani Center, Bet Dagan 50250, Israel,¹ Department of Plant Sciences, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel,² Central Laboratories, Ministry of Health, Jerusalem 94467, Israel³

Received 5 July 2007/ Accepted 26 September 2007

Pantoea agglomerans has been transformed from a commensal bacterium into two related gall-forming pathovars by acquisition of pPATH plasmids containing a pathogenicity island (PAI). This PAI harbors an hrp/hrc gene cluster, type III effectors, and phytohormone biosynthetic genes. DNA typing by pulsed-field gel electrophoresis revealed two major groups of P. agglomerans pv. gypsophilae and one group of P. agglomerans pv. betae. The pPATH plasmids of the different groups had nearly identical replicons (98% identity), and the RepA protein showed the highest level of similarity with IncN plasmid proteins. A series of plasmids, designated pRAs, in which the whole replicon region (2,170 bp) or deleted derivatives of it were ligated with nptI were generated for replicon analysis. A basic 929-bp replicon (pRA6) was sufficient for replication in Escherichia coli and in nonpathogenic P. agglomerans. However, the whole replicon region (pRA1) was necessary for expulsion of the pPATH plasmid, which resulted in the loss of pathogenicity. The presence of direct repeats in the replicon region suggests that the pPATH plasmid is an iteron plasmid and that the repeats may regulate its replication. The pPATH plasmids are nonconjugative but exhibit a broad host range, as shown by replication of pRA1 in Erwinia, Pseudomonas, and Xanthomonas. Restriction fragment length polymorphism analyses indicated that the PAIs in the two groups of P. agglomerans pv. gypsophilae are similar but different from those in P. agglomerans pv. betae. The results could indicate that the pPATH plasmids evolved from a common ancestral mobilizable plasmid that was transferred into different strains of P. agglomerans.

Published ahead of print on 5 October 2007.

Supplemental material for this article may be found at http://aem.asm.org/.

Contribution no. 505/07 from ARO, the Volcani Center, Bet Dagan, Israel.