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Changes in growth and the level of various cellular constituents were monitored for 96 h after transfer of stationary phase cells of Catharanthus roseus to fresh complete (“+Pi”) or phosphate deficient (“-Pi”) Murashige-Skoog medium. In the cultures transferred to “+Pi” medium, cell number and fresh weight increased rapidly after an initial lag period, while little or no increase in cell number or fresh weight was observed in cultures transferred to “-Pi” medium. The levels of ATP, glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), RNA and protein, increased in the cultures in “ + Pi” medium, while the levels of free amino acids decreased. In contrast, we found a decrease in the levels of ATP, G6P and F6P and an increase in the levels of free amino acids in the cultures in “-Pi” medium. Appreciable DNA synthesis was observed only in cells growing in “+Pi” medium, at 72 h after cell transfer. The rate of RNA synthesis in the “+Pi” culture was generally higher than that in the “-Pi” culture. The levels of ethanol soluble-phenolic compounds increased transiently in the cells grown in both media just after cell transfer, but the level in the “+Pi” culture decreased progressively with cell division. The metabolic role of inorganic phosphate in metabolism of Catharanthus roseus cells is discussed.

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