Genetic transformation of cucumber (Cucumis sativus L.) by agrobacterium tumefaciens and plant regeneration

Cotyledon and HBpocotyl segments of cucumber (Cucumis sativus L.) were used for the transformation performed by EHA101 strain of A. tumefaciens harboring the binary vector pGA482GG plasmid carrying the marker genes the neomycin phosphotransferase II (npt II) determining resistance to kanamycin and P- glucuronidase (GUS). Cotyledon and hipocotyl segments of plants which were obtained w vitro conditions were cultivated on MS medium containing different hormones combination and concentrations. The best suitable shoot regeneration medium was observed on MS medium containing 2 mg/L zeatin. In the tested tissues segments, the highest shoot regeneration was obtained from the proximal ends of cotyledon leaves which were cut transversely into two halves. Plant tissue segments co-cultivated with A. tumefaciens for 2 days. Plant tissue, selected in the MS medium containing kanamycin were tested by histochemical GUS+ assays and blue color staining was observed on the tissues. Shoots regenerated from the transgenic tissue were cultured on the basal MS medium to induce root formation for 3 weeks. The rooted plants with 10 cm height were transferred to the soil for their adaptation to the natural environment. It was observed that plants had normal flower and fruit. DNA was isolated from transgenic plants and PCR analyzes were done to indicate transferred npt II and GUS genes. Thus an effective protocol for Agrobacterium- mediated genetic transformation of cucumber was set up. Key words; Agrobacterium tumefaciens, Cucumis sativus, Transgenic Plant, Plant Regeneration, Cucumber