Background
Efficient transformation and regeneration
Conclusions
The phenotypic homogeneity of the regenerated plants highlights the validity of this method for both propagation and genetic transformation of table grape cultivars. Expression of the DefH9-iaaM gene takes place in young flower buds of transgenic plants from both grape cultivars.
Results
Transgenic grape plants (V. vinifera, table-grape cultivars Silcora and Thompson Seedless) were produced using a method based on regeneration via organogenesis. In vitro proliferating shoots were cultured in the presence of increasing concentrations of N6-benzyl adenine. The apical dome of the shoot was removed at each transplantation which, after three months, produced meristematic bulk tissue characterized by a strong capacity to differentiate adventitious shoots. Slices prepared from the meristematic bulk were used for Agrobacterium-mediated transformation of grape plants with the gene DefH9-iaaM. After rooting on kanamycin containing media and greenhouse acclimatization, transgenic plants were transferred to the field. At the end of the first year of field cultivation, DefH9-iaaM grape plants were phenotypically homogeneous and did not show any morphological alterations in vegetative growth. The expression of DefH9-iaaM gene was detected in transgenic flower buds of both cultivars. Conclusions: The phenotypic homogeneity of the regenerated plants highlights the validity of this method for both propagation and genetic transformation of table grape cultivars. Expression of the DefH9-iaaM gene takes place in young flower buds of transgenic plants from both grape cultivars.