Genetic transformation of the medicinal plant Ruta graveolens L. by an Agrobacterium tumefaciens-mediated method

Ruta graveolens L. is a source of pharmacologically active molecules such as furocoumarins, furoquinolines and acridone alkaloids. A genetic transformation method using Agrobacterium tumefaciens was developed for this plant species. The conditions for an efficient regeneration of R. graveolens led us to retain hypocotyls among other explants tested. Subsequently, transformation was obtained by co-cultivation of hypocotyls of 2-3 weeks old plants and A. tumefaciens strain C58C1RifR containing a plasmid harboring neomycin phosphotransferase and β-glucuronidase encoding genes. PCR analyses using β-glucuronidase-primers showed that 78% of the transgenic plants selected for kanamycin resistance were transformed with the gene encoding β-glucuronidase and 67% of them exhibited the corresponding enzymatic activity. Chromosomic integration of β-glucuronidase encoding gene was verified by Southern blotting. Routine transformation efficiency of R. graveolens L. was established at 11% and could reach 22% in some experiments. This is the first report of a method to transform genetically R. graveolens L.