The effect of a large number of Tn3 insertions in the vir region of the Ti plasmid pTiA6NC on the virulence of Agrobacterium was determined. The Vir- insertions were mapped in three of the five loci that have been defined previously. Merodiploid Rec- strains carrying one insertion mutation on the Ti
Genetic complementation of Agrobacterium tumefaciens Ti plasmid mutants in the virulence region
โ Scribed by Lundquist, Ronald C. ;Close, Timothy J. ;Kado, Clarence I.
- Publisher
- Springer
- Year
- 1984
- Tongue
- English
- Weight
- 798 KB
- Volume
- 193
- Category
- Article
- ISSN
- 0026-8925
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โฆ Synopsis
Mutants with Tn5 insertions in the vir region of the Agrobacterium tumefaciens TiC58 plasmid are unable to form crown-gall tumors. Complementation tests of these vir region mutants were carried out by constructing merodiploids in a recombination-deficient strain. Each merodiploid possessed a mutant TiC58 plasmid and a recombinant plasmid containing either the homologous wild-type DNA region or the homologous region containing a second Tn5 insertion. The analysis identified six complementation groups. Mutations in one of these complementation groups were not complemented in trans and represent a cis-dominant locus. The mutation in one complementation group showed variation in host range.
๐ SIMILAR VOLUMES
The Ti-plasmids are naturally self-transmissible from their normal host Agrobacterium to E. coli. They are however unable to stably establish themselves as a replicon in E. coli. It is nevertheless possible to study the Ti-plasmids in E. coli with the help of Ti::RP4 cointegrate plasmids that transf