Transient gene expression in strawberry (Fragaria x ananassa Duch.) protoplasts and the recovery of transgenic plants

Summary A transient ß-glucuronidase (GUS)-assay was performed to evaluate electroporation parameters and optimize DNA delivery conditions into strawberry protoplasts. Optimal GUS-activity was obtained when protoplasts were subjected to 400 V/cm for 20 ms. GUS-activity could be further increased by the addition of carrier DNA to the electroporation mixture. Callus selected on 10 g/ml hygromycin produced shoots which exhibited GUS-activity. The transformed nature of the shoots obtained after selection was confirmed by DNA-analysis.Abbreviations CaMV cauliflower mosaic virus - dCTP deoxycytidine-triphosphate - EtBr ethidium bromide - GUS ß-glucuronidase - MES 2(N-morpholino) -ethanesulfonic acid - X-gluc 5-bromo-4-chloro-3-indolyl glucuronide