Tumors - the plant hyperplasia symptoms- - induced by species of Agrobacterium sp. have deeply impressed plant pathologists since early 20th Century when Erwin Smith and his co-workers demonstrated that such tumors had a bacterial etiology. Nevertheless, until recently the state of art of Microbiology and Molecular Biology was not developed enough for scientists to realize and to elucidate the complexes biochemical, genetic and physiologic mechanisms by which the pathogen transforms the plant by inserting a region of its own plasmid into the genome of the latter, creating an specific ecological niche for itself. In this paper its is showed a historical brief on the evolution of knowledge about the genomic characteristics of the Ti Plasmid, events and requirements needed for infection to take place as well as it is discussed the transformation dynamics of the host by the pathogen.
Tumors; Phytobacteria; Oncogeny; Transformation; Ti plasmid
