ISSN:
1573-5028
Keywords:
Agrobacterium
;
Ti plasmid
;
oncogenes
;
e gene
;
3′ gene
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006370207379
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