Efficient transformation systems for tuber discs of Solanum tuberosum, leaf discs of Nicotiana tabacum and internodes of both species were achieved with Agrobacterium rhizogenes 8196. Hairy root formation ratio per inoculated explant was 31.25 % for tubers and 60 % for internodes of potato. In the case of tobacco this ratio was, 55.6 % for leaf discs and 64 % for internodes in MS media supplemented with 1 mg/l NAA. Transformation was confirmed with Southern hybridization [gamma(32) P] CTP labeled Ri plasmid segments. Methods developed will be used for further gene transfer studies with the aim of molecular farming.