Exploitation of plant cells for the production of natural compounds.

A four-step strategy is presented which allows the establishment of plant cell cultures producing high yields of secondary plant products. The application of suitable methods (radioimmunoassay, fluorescence screening) for the selection of overproducing differentiated plants and cell colonies is stressed. By precursor feeding and hormone application, plant cell cultures can greatly be influenced in their production behavior. A highly sensitive, selective regulatory mechanism for the uptake and storage of alkaloids in Catharanthus vacuoles is demonstrated. Overproducing variant cell strains are so far the most promising tool for the future biotechnological application of the plant cell culture method.