Homology studies demonstrate colinear organization of the transferred regions of plasmids pRi 1855 and pRi 8196 from Agrobacterium rhizogenes.
Agrobacterium rhizogenes, a pathogenic bacterium determining for hairy-root tumors in plants, acts by insertion of a fragment (T-DNA) of its Ri plasmid into the plant nuclear DNA. Two A. rhizogenes strains, pRi 1855 and pRi 8196, responsible for similar disease symptoms, differ when compared at the structural level. However, some morphogenetic loci previously identified by insertion mutagenesis in either one of the two T-DNAs seem physiologically equivalent. The possibility that these morphogenetic loci are structurally similar was tested by cross-hybridization studies. Our data allow establishment of an unequivocal correspondence between the two T-DNA maps where apparently equivalent morphogenic loci occupy similar positions which suggests that the observed structural homologies also reflect physiological similarities between both T-DNAs.
D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D010957:Plasmids; D012231:Rhizobium / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D004269:DNA, Bacterial