Biolistic transformation of wheat using the HMW-GS 1Dx5 gene without selectable markers.

Genetic manipulation using linear DNA was applied to the common wheat variety Xindong No. 26 via particle bombardment with the aim to improve bread-making quality of flour. Initially, 2 biolistic parameters, helium pressure and target distance, were optimized using plasmid pAHC25. We transformed wheat immature embryo scutella with the linear 1Dx5 gene without selectable markers. The highest transient β-glucuronidase expression was obtained when scuttles were bombarded at 1100 psi with a 9-cm target distance. Using the optimized parameters, the transformation of the common wheat variety Xindong No. 26 was carried out using the linear 1Dx5. Three transgenic plants were identified from 1003 transgenic plants, yielding a transformation frequency of 0.4%. A sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis confirmed that the 1Dx5 gene was expressed in 4 T1 seeds of the transgenic plants. These experiments indicate the possibility of obtaining marker-free transgenic wheat plants via particle bombardment using the minimal gene cassettes with the particle bombardment parameters.