Method for the transfer of large cryptic, non-self-transmissible plasmids: Ex planta transfer of the virulence plasmid of Agrobacterium rhizogenes [Genetic engineering]

• Published in: Plasmid Vol. 8; no. 1; pp. 94 - 96
• Main Authors: Hooykaas, P.J.J., den Dulk-Ras, H., Schilperoort, R.A.
• Format: Journal Article
• Language: English
• Published: United States 01.01.1982
• Subjects: Agrobacterium rhizogenes; Agrobacterium tumefaciens; Bacteriological Techniques; DNA Transposable Elements; Genetic Techniques; Plasmids; Recombination, Genetic; Rhizobium - genetics
• ISSN: 0147-619X; 1095-9890
• DOI: 10.1016/0147-619X(82)90046-4

A method is presented for the (ex planta) transfer of large, cryptic plasmids that are (phenotypically) non-self-transmissible. The procedure consists of introducing a mobilizing R plasmid into the strain carrying the cryptic plasmid followed by random transposon mutagenesis (e.g. by conjugation with a bacterium carrying a suicide plasmid). The method was applied for the labeling of a large cryptic plasmid present in A. rhizogenes 1855 and for its subsequent ex planta transfer to a Ti plasmidless A. tumefaciens strain. The plasmid gave the new host the capacity to induce the hairy root disease in plants, and thus turned out to be an Ri plasmid. From labeled Ri plasmid derepressed mutants were isolated that were transmissible both in planta and ex planta.