Accumulation of Vismione-a In Regenerated Plants of Vismia-guianensis Dc

The accumulation and tissue localization of antitumoral vismione A in the in vitro regenerated plants of Vismia guianensis DC. were investigated. Chemical and light and electron-microscope analyses revealed that vismione A, detected as phenolic black globules in the vacuoles, was accumulated in the leaf, mainly in the palisade, and in small amounts in the primary body of the stem (epidermis and first cortical layer). Vismione A is neither present in the secretory cavities and ducts of the leaf nor in the secretory ducts of the stem. In the leaves of the regenerated plants, the amount of vismione A reached 0.5% RV; compared to 0.1% in the leaves of the parent plant. The optimization of the in vitro regeneration of plants was obtained in MS medium enriched with BAP(1 ppm). The best results for the rooting of regenerated plants were achieved with MS medium containing half-strength salts and 10(-5) M IBA.