Fructan Synthesis in Tissue Cultures of Symphytum officinale; L. Initiation, Differentiation, and Metabolic Activity.

Tissue cultures originating from different organs i.e. leaves, leaf-stalks, ovaries, anthers, and roots of SYMPHYTUM OFFICINALE were initiated under various growth conditions and subcultured several times to give the first callus generation. From all these calli, whole plants could be regenerated which again were used for the preparation of tissue cultures resulting in the formation of the second callus generation. The different calli and the regenerated plants were analyzed with respect to the fructan-synthesizing capacity. Only calli derived from the leaves of the original plant synthesized fructan whereas calli derived from ovaries, anthers, and roots, which are known to contain large amounts of fructan, were not capable of synthesizing fructan. The regenerated plants obtained from the first callus generation showed ability for fructan synthesis only if the originating callus synthesized fructan. The calli of the second generation, which were prepared from fructan-containing leaves and roots of regenerated plants, showed the capacity for fructan formation. The calli of the second generation obtained from leaves and roots of regenerated, fructan-free plants were not able to synthesize this specific reserve polysaccharide. From these data it can be concluded that the calli of the first generation prepared from roots, ovaries, and anthers have lost their ability for fructan synthesis. Calli initiated from leaves and leaf-stalks preserved the capacity for fructan formation even after many calli generations and regeneration to entire plants. Different phytohormones used in the tissue cultures had only a slight effect upon the fructan formation. An influence of light on fructan synthesis could not be detected.