High efficiency transformation of peppermint (Mentha x piperita L.) with Agrobacterium tumefaciens

Transgenic peppermint (Mentha x piperita L.) plants were obtained by using Agrobacterium tumefaciens-mediated gene transfer. The effects of the coculture period and of the Agrobacterium strain were tested. 10% transformed plants were regenerated by leaf disk culture after inoculation with strain EHA105/MOG harbouring beta-glucuronidase and neomycin phosphotransferase II genes, with a coculture period of 5 days. Rooting of regenerated plants was achieved on selective medium with 150 mg/l kanamycin. The presence of transgenes in DNA was shown through PCR and Southern blot hybridization and transgene product activity via histoenzymatic GUS test and leaf callus assay. Transgenic plants were successfully acclimatized in the greenhouse. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.