TOWARDS AGROBACTERIUM – MEDIATED TRANSFORMATION OF THE ENDANGERED MEDICINAL PLANT GOLDEN ROOT

Abstract

Medicinal plants preparations are still the most popular life saving remedies for a larger part of the world population. However, exhaustion of natural resources demands new approaches in utilization and protection of these species. Biotechnology may be a powerful tool for enhancing the productivity of novel secondary metabolites. In recent years Agrobacterium mediated plant transformation, due to its simplicity and efficiency, has become quite used method for the introduction of foreign genes into plant cells followed by regeneration of genetically improved plants. The approach was successful in a number of technical and food crops but it is still limited in medicinal plants. One of the most appropriate methods for medicinal plants engineering is genetic transformation leading to increased synthesis of biological active substances in root cultures or in regenerated plantlets. Rhodiola rosea is a medicinal plant with limited area of distribution. Roots and rhizomes contain biological active substances used in prevention and treatment of socially important diseases. This article illustrates the possibilities of biotechnology for regeneration of Golden root and for genetic transformation aiming at stimulation of secondary metabolite production in vitro. Efficient system for propagation in vitro was developed using leaf nodes explants and was used for the genetic transformation experiments. Agrobacterium rhizogenes ATCC 15834 was used for hairy roots induction. Various factors (like density of bacterial suspension, co-cultivation time duration, concentration of the selective antibiotic) with impact on the efficiency of the transformation procedures were studied. Three transformation methods were compared: (i) spilling drops of bacterial suspension on the explants; (ii) injuring explants and dipping them into the bacterial suspension; (iii) injecting plantlets. Favorable and frustrating conditions were observed and discussed.