Sequence and functional analysis of the left-hand part of the T-region from the nopaline-type Ti plasmid, pTiC58.
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.
Otten
L
L
Institute for Plant Molecular Biology of the CNRS, Strasbourg, France.
Salomone
J Y
JY
Helfer
A
A
Schmidt
J
J
Hammann
P
P
De Ruffray
P
P
D016960:Agrobacterium tumefaciens / Q000235:genetics* / Q000472:pathogenicity; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D017353:Gene Deletion; D005798:Genes, Bacterial / Q000235:genetics; D005816:Genetic Complementation Test; D018551:Solanum lycopersicum / Q000235:genetics / Q000382:microbiology; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D010941:Plant Tumors / Q000235:genetics / Q000382:microbiology; D010946:Plants, Medicinal / Q000235:genetics / Q000382:microbiology; D010947:Plants, Toxic; D010957:Plasmids / Q000737:chemistry / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014026:Nicotiana / Q000235:genetics / Q000382:microbiology; D014774:Virulence / Q000235:genetics
D004269:DNA, Bacterial; C036483:T-DNA