ABSTRACT
In recent decades plant cell cultures have been favoured by plant biotechnologists for the production of prospective raw materials. Plant cell cultures have generally proved to be beneficial for biochemical and physiological studies, but progress is rather slow and difficult to predict when considering the economically important compounds (Drapeau et al., 1987). A major problem is that plant secondary metabolism is regulated in an organ-, tissue-or development-specific process in the intact plant (Wink, 1989). The correct expression of the genes for biosynthesis and storage appears to be difficult to control in undifferentiated plant cells or callus cultures. Many researchers have solved these problems by employing organized tissue cultures, such as root or shoot cultures, which were facilitated by the use of transformation of plant tissue (Hamill et al., 1987; Williams and Ellis, 1993; Nessler, 1994).
