Backbone-free transformation of barrel medic (Medicago truncatula) with a Medicago-derived transfer DNA.

In the present work, Agrobacterium tumefaciens-mediated genetic transformation of the model legume Medicago truncatula Gaertn. (barrel medic) was carried out using the pSIM843 vector that contains a Medicago-derived transfer DNA, delineated by a 25-bp sequence homologous to bacterial T-DNA borders. The transfer DNA contains an expression cassette for the nptII (neomycin phosphotransferase) gene and is flanked by an expression cassette for the backbone integration marker gene ipt (isopentenyl transferase).