Studies on the Evolution of Agrobacterium vitis as Based on Genomic Fingerprinting and IS Element Analysis

Abstract

Summary In order to study evolutionary relationships of the crown gall pathogen on grapevine, Agrobacterium vitis , bacterial genomes were analyzed by genomic fingerprinting. Additionally, A. vitis specific IS elements were used as chromosomal markers to establish genetic relations obtained by restriction analysis. DNA fragments up to 1 Mb in size were produced by digestion of genomic DNA with the rare cutting restriction endonucleases Xba I, Sfi I, and Spe I and separated by pulsed field gel electrophoresis (PFGE). As the result of the macrorestriction analysis of 42 strains six genomic groups with homologous restriction patterns could be identified. Based on similarity coefficients of more than 0.8 A. vitis strains were allocated to one of the six genome types. For every genome type defined, a distinct IS element pattern was found. The synopsis of IS element patterns and genomic fingerprinting allowed the construction of a phylogenetic tree on the evolution of different genome types within A. vitis .