PCR detection of Ti and Ri plasmids from phytopathogenic Agrobacterium strains.

A universal primer set (VCF/VCR) for PCR analysis based on the sequences of the virC operon located on Ti and Ri plasmids was designed to detect these plasmids from phytopathogenic Agrobacterium strains. With the VCF (sequence, 5'-ATCATTTGTAGCGACT-3') and VCR (sequence, 5'-AGCTCAAACCTGCTTC-3') primer set, DNA fragments of 730 bp in length were amplified from cell lysates of 10 rhizogenic and 65 tumorigenic agrobacteria. DNA sequencing and Southern hybridization analysis confirmed that the amplified fragments corresponded to the target region. The PCR method is considered convenient for routine determination of the potential pathogenicity of Agrobacterium strains.