Abstract： Cell suspension culture of Saussurea medusa was cultivated with either Ce3+, La3+, Nd3+ or a mixture of rare earth elements (MRE) supplemented. After 20 d culture, moderate concentrations of Ce3+, La3+ and MRE can promote cell growth and flavonoids biosynthesis, while Nd3+ presented an inhibitting effect. Ce3+ at 0.025 mmol/L, gave the highest cell dry weight (17.7 g/L) and flavonoids production (942 mg/L) with both NAA and 6-BA in the culture medium. They were 34% and 67% higher than those without Ce3+ addition, respectively. Ce3+ at 0.005~0.05 mmol/L or the mixture of rare earth elements at 0.01~0.025 mmol/L, can substitute for 6-BA in promoting cell growth and the biosynthesis of total flavonoids of S. medusa while without 6-BA in the culture medium. When NAA were removed from the culture medium, none of the four rare earth elements can substitute for it in promoting S. medusa cell growth and the flavonoids biosynthesis. The kinetic curves of cell biomass, flavonoids production, residual sugar, NH4+ and NO3- concentration with or without 0.025 mmol/L Ce3+ in the culture medium were also obtained. The mechanism of the promotion effect of Ce3+ on cell growth and the biosynthesis of total flavonoids of Saussurea medusa was explained in some degree.
2004, Vol. 4 
