Agrobacterium rhizogenes-transformed roots of Astragalus membranaceus (Fisch. Ex Link) Bunge as a source of valuable secondary metabolites

In this study the results of agrobacterial transformation of Astragalus membranaceus (Fisch. Ex Link) Bunge, a medicinal plant from Mongolia and China with a wide spectrum of pharmacological action were presented. As explants for transformation, in vitro derived microshoots as well as hypocotyls, cotyledons and primary shoots isolated from seedlings were used. The most effective from two tested Agrobacterium rhizogenes strains (A4-RT, 15834 SWISS) was 15834 SWISS, causing the transformation of various types of explants, including primary shoots as a more responsive type. The optimal co-cultivation time of explants with bacterial suspension (48 hours) and the highest transformation rate of primary shoots (36.4%) were established. PCR analysis confirmed the transgenic nature of the roots transformed with strain 15834 SWISS and the absence of bacterial contamination.