Sequence and functional analysis of the left-hand part of the T-region from the nopaline-type Ti plasmid, pTiC58.

Abstract

The Agrobacterium tumefaciens nopaline strain C58 transfers a large, 29 kb T-DNA into plant cells during infection. Part of this DNA (the 'common DNA') is also found on the T-DNA of octopine strains, the remaining DNA is nopaline strain-specific. Up to now, only parts of the C58 T-DNA and related T37 T-DNA have been sequenced. We have sequenced the remainder of the nopaline-specific T-DNA (containing genes a to d) and acs to iaaM. Gene c codes for a new unknown T-DNA protein. Gene a is homologous to the agrocinopine synthase gene. Genes b, c', d and e are part of a larger family: they are related to the T-DNA genes 5, rolB, lso and 3'. Genes 5, rolB and lso induce or modify plant growth and have been called T-DNA oncogenes. Our studies show that gene 3' (located on the TR-DNA of octopine strains) is also oncogenic. Although the b-e T-DNA fragment from C58 and its individual genes lack growth-inducing activity, an a-acs deletion mutant was distinctly less virulent on Kalanchoe daigremontiana and showed reduced shoot formation on Kalanchoe tubiflora. Shoot formation could be restored by genes c and c' in co-infection experiments. Contrary to an earlier report, a C58 e gene deletion mutant was fully virulent on all plants tested.

• Authors: L Otten, J Y Salomone, A Helfer, J Schmidt, P Hammann, P De Ruffray
• Journal: Plant molecular biology (Plant Mol Biol) Vol. 41 Issue 6 Pg. 765-76 (Dec 1999) ISSN: 0167-4412 [Print] Netherlands
• PMID: 10737141 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Bacterial
• T-DNA

Topics

• Agrobacterium tumefaciens (genetics, pathogenicity)
• Chromosome Mapping
• DNA, Bacterial (chemistry, genetics)
• Gene Deletion
• Genes, Bacterial (genetics)
• Genetic Complementation Test
• Solanum lycopersicum (genetics, microbiology)
• Molecular Sequence Data
• Mutation
• Phylogeny
• Plant Tumors (genetics, microbiology)
• Plants, Medicinal (genetics, microbiology)
• Plants, Toxic
• Plasmids (chemistry, genetics)
• Sequence Analysis, DNA
• Species Specificity
• Tobacco (genetics, microbiology)
• Virulence (genetics)