Agrobacterium tumefaciens gene transfer to Casuarina glauca : a tropical nitrogen-fixing tree

Transgenic calli of the tropical tree #Casuarina glauca were produced using #Agrobacterium tumefaciens-mediated gene transfer. Hypocotyls, cotyledons and epicotyls were excised from 30-60-day old #Casuarina seedlings and cocultivated with #Agrobacterium strain C58C1(pGV2260) containing the binary vector BIN19GUSINT. Transformed calli were selected on nutrient medium supplemented with 0,5 microM NAA, 2,5 microM BA and 50 mg/l kanamycin. Some of the factors influencing T-DNA transfer to #C. glauca$ explants were studied. Optimal transformation rates were obtained when explants from 45-day old seedlings were cocultivated for 3 days in the presence of 25 microM acetosyringone. Transgenic buds differentiated on 10% of the calli grown on transformed epicotyls. Evidence for genetic transformation was obtained by beta-glucuronidase assay, PCR and Southern hybridization. (Résumé d'auteur