Elimination of agrobacteria from transgenic plants

Genetically engineered agrobacteria are routinely used to transform crop pl ants. These agrobacteria can obviously persist within the transgenic plants although they are not tumorgenic [1-4]. Our attempts to eliminate the agro bacteria concentrate on the regeneration of secondary shoots from infected tobacco plants. Application of the antibiotics cefotaxim or carbenicillin d uring the regeneration process did not result in sufficient reduction of th e bacterial contamination. Shoot tip culture of apical meristems, however, resulted in a large percentage of agrobacteria-free regenerated plants (wit hin the detection limits). The degree of plant contamination with agrobacte ria was determined by Polymerase Chain Reaction (PCR).