Transformation of potato (Solanum tuberosum) using particle bombardment

Internodes, leaves and tuber slices from potato (Solanum tuberosum), genoty pe 1024-2, were subjected to particle bombardment. Transient expression was optimized using the uidA and the luc reporter genes that encode beta -gluc uronidase (GUS) and luciferase, respectively. Stable transformation was ach ieved using the neomycin phosphotransferase (nptII) gene, which confers res istance to the antibiotic kanamycin. The influence of biological parameters (tissue type, growth period before bombardment, pre- and post-bombardment osmoticum treatment) and physical parameters (helium pressure, tissue dista nce) that are known to possibly affect stable transformation were investiga ted. Putative transgenic plants, which rooted in media containing kanamycin , were obtained from all of the tissues tested although there were large di fferences in the efficiency: internodes (0.77 plants per bombarded explant) , microtuber slices (0.10 plants per bombarded explant) and leaves (0.02 pl ants per bombarded explant). Southern blot analysis of putative transgenic plants confirmed the integration of the transgenes into plant DNA. The resu lts indicate that an efficient particle bombardment protocol is now availab le for both transient and stable transformation of potato internodal segmen ts, thus contributing to an enhanced flexibility in the delivery of transge nes to this important food crop.