Genetically transformed roots as a model system for studying physiological and biochemical processes in intact roots

The sequence of operations during plant genetic transformation using wild strains of the soil bacterium Agrobacterium rhizogenes and subsequent root production capable of long-term growth on the relatively simple media free of growth compounds are described. The basic morphological, physiological, and biochemical characteristics of transformed roots are reported, and a technology of their in vitro cultivation is described. The modes of growth optimization of long-term cultivated roots of valuable plants and of the increase in the concentration of secondary metabolites synthesized by these roots are enumerated. The efficiency of the method of so-called “artificial seed” application for preservation of valuable lines of cultivated roots and a possibility of their healthy state restoration are briefly appraised. On the basis of literature and our own experiments, the main directions for the usage of genetically transformed roots in applied and fundamental studies are outlined. The terminology used for designation of genetically transformed roots by Russian researches is briefly discussed. Main materials and equipment required for plant transformation with the soil bacterium and for the maintenance of long-term growth of obtained roots are listed.