A high-throughput transformation system allows the regeneration of marker-free plum plants (Prunus domestica)

A high-throughput transformation system previously developed in our laboratory was used for the regeneration of transgenic plum plants without the use of antibiotic selection. The system was first tested with two experimental constructs, pGA482GGi and pCAMBIAgfp94(35S) that contain selective marker and reporter genes. Transformation was monitored by GUS detection, and estimated transformation efficiencies were 5.7% and 17.7% for pGA482GGi and pCAMBIAgfp94(35S), respectively. Subsequently, an intron-hairpin-RNA (ihpRNA) construct, carrying the Plum Pox Virus coat protein (ppv-cp) gene, without selectable or reporter marker genes was designed. Five transgenic lines were regenerated as confirmed by DNA blot analysis. We believe that this is the first report on the production of marker-free plants transformed with a potential agronomically important trait in a Prunus species.