Gamma Radiation Effect on Agrobacterium tumefaciens-Mediated Gene Transfer in Potato (Solanum tuberosum L.)

Potato (Solanum tuberosum L.) is one of the major crops of the world. Significant improvements can be achieved in terms of yield and quality by the determination of efficient transformation methods. On the other hand, low transformation frequency seriously limits the application of molecular techniques in obtaining transgenic crops. In the present study, the effect of gamma radiation on Agrobacterium tumefaciens-mediated transformation to the potato was firstly investigated. Sterile seedlings of potato cv. ‘Marabel’, which was grown on Gamborg’s B5 medium in Magenta vessels, were irradiated with different gamma radiation doses (0-control, 40, 80, 120 Gy 60Co). Stem parts having axillary meristems were excised from irradiated seedlings and inoculated by A. tumefaciens (GV2260), which harbors the binary plasmid p35S GUS-INT contains and GUS (β-glucuronidase) gene controlled by 35S promoter (CaMV) and nptII (neomycin phosphotransferase II) gene driven by NOS (nopaline synthase) promoter). Inoculated stem parts having axillary meristems explants were then directly transported to a selection medium containing duocid (500 mg l−1), and kanamycin (100 mg l−1), 4 mg l−1 gibberellic acid, 1 mg l−1 BAP and 0.1 mg l−1 NAA. The adult transgenic plants were detected by polymerase chain reaction (PCR) analysis. According to the number of transgenic plants determined by PCR analysis, results obtained from explants treated with 40 Gy gamma gave the best results compared to the control (0 Gy) application. The doses over 40 Gy were also found statistically significant compared to the control (0 Gy). It is expected that the protocol described in this study make the transformation studies easier by skipping the stages of ‘co-cultivation’, ‘culturing explants on selection medium’ and ‘recovery of transgenic shoots on selection medium’ not only for potato but also for other crop plants. This study was supported by a grant from the Scientific and Technological Research Council of Turkey (TUBİTAK) (Grant number 113O280 to Prof. Dr. Mustafa YILDIZ).