For the transfer of a $beta$ -Glucuronidase (GUS) reporter gene to sugarbeet (Beta vulgaris L.) callus and leaf explants by microprojectile bombardment, various rupture disk pressures and sample plate distances were tested. By coating the pBI221.23 DNA construct over the gold particles, bombardments were carried out by the DuPont PDS-1000/He system and the results clearly indicated the superiority of leaf explants over the callus structures as targets. The sample plate distances affected the distribution pattern of the particles and the cells expressing the GUS reporter gene were noted to be aggregated in short distances whereas longer distance shots yielded better distribution of transformed cells. For both leaf explants and callus structures the rupture disk pressure of 1350 psi was observed to yield the highest gene expression results and the sample plate distance of 12 cm for the leaf explants and 9 cm for the callus were found to increase the penetration success of the gold particles.

For the transfer of a $beta$ -Glucuronidase (GUS) reporter gene to sugarbeet (Beta vulgaris L.) callus and leaf explants by microprojectile bombardment, various rupture disk pressures and sample plate distances were tested. By coating the pBI221.23 DNA construct over the gold particles, bombardments were carried out by the DuPont PDS-1000/He system and the results clearly indicated the superiority of leaf explants over the callus structures as targets. The sample plate distances affected the distribution pattern of the particles and the cells expressing the GUS reporter gene were noted to be aggregated in short distances whereas longer distance shots yielded better distribution of transformed cells. For both leaf explants and callus structures the rupture disk pressure of 1350 psi was observed to yield the highest gene expression results and the sample plate distance of 12 cm for the leaf explants and 9 cm for the callus were found to increase the penetration success of the gold particles.