Production by Means of Plant Cell Cultures

Even if all the genes were known, transferring a large number of genes to a microorganism is not feasible, particularly as the enzymes produced have to act in a concerted way. Furthermore, in plants secondary metabolism is often compartmentalized on the subcellular or even cellular level. This will be impossible to realize in microorganisms. 

As genetic engineering of microorganisms does not seem to be a feasible approach, one should exploit the genetic information of the plant cell itself. Plant cells are totipotent, which means that each cell carries all the genetic 

Secondary metabolism is a form of differentiation, but cells grown in vitro are rapidly dividing, undifferentiated cells. Only at the end of the growth phase of batch-cultured cells may some form of differentiation occur, connected with the production of secondary metabolites. A plant produces a wide variety of secondary metabolites, all with different, mostly unknown functions. In in vitro cultured cells those compounds which defend the plant against microorganisms, namely, phytoalexins, are often easily formed. For example. Cinchona cell cultures produce large amounts of anthraquinones, but the alkaloids of interest, the quinolines, are produced in trace amounts only. Similarly Papaver cell cultures produce sanguinarine and closely related alkaloids, but no morphinane alkaloids. 

The various strategies followed to obtain high producing cell lines will be briefly discussed separately (see Section II). The economics of a plant cell culture production process are discussed below (see Section III). For cell lines that do not produce, it will be necessary to learn more about the regulation of secondary metabolism in order to eventually be able to use genetic engineering for improving production (see below). 

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A large number of various fine chemicals is derived from plants, e.g., drugs, pigments, and other biologically active substances. In the past, their production by means of plant cell cultures has attracted the interest of many researchers. Although most plant cell cultures have been unable to... 

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