Study On Regulation Of Biosynthesis Of Flavonoids And Cultures Of Hairy Root In Saussurea Medusa

Saussurea medusa Maxim,family compositae,is a famous Chinese traditional drug, in which the flavonoids were its main bioactive components. Because of the poor natural resources, the feasibility of flavonoids production by hairy root cultures of S. medusa was demonstrated in this paper. The effects of different physical and chemical factors on hairy root growth and flavonoids production were investigated in hairy root culture of Saussurea medusa. 1/2 MS medium was used in this investigate. The results showed that the following culture conditions : nitrogen concentratiaon(involved NH₄⁺ and NO₃^-),30 mmol/L; the ratio of ammonium to nitrate,5:25; the combination of 2 % sucrose and 3 % glucose; 0.5 mg/L GA3 ; 0.5 mg/L IBA; initial pH 5.8; light cycle,18 h/d(3500 Lux); temperature,24℃; shaker revolutions per minute,100 rpm, were favourable to hairy root growth and flavonoids production. Under the above culture conditions, up to 12.8 g/L(DW) of hairy root and 1922 mg/L of flavonoids were obtained after 21 days of culture. The content of total flavonoids in hairy root dried weight was 15 %, which was about 25 times as that in the wild plantlet. The flavonoids production in the hairy root cultures of Saussurea medusa was affected by the treatment of two eliciters (MJ and SA)sepratately. Under the optimum culture conditions, both of them could enhance the flavonoids production. The results showed that MJ increased the content of flavonoids with inhibition of the hairy root growth; However, SA increased the growth of the hairy root and decreased the content of flavonoids. The results showed that elicitation was dependent on the elicitor concentration and the treatment time. The optimum concentration in treatment with MJ was 0.02 mmol/L, the maximum flavonoids yields of 849 mg/L were obtained at the late lingering growth stage, which was 34.1 % higher than the control(633 mg/L).The optimum concentration of SA was 0.03 mmol/L, and the maximum flavonoids yields of 968 mg/L, which was 52.9 % higher than the control(633 mg/L), were found at the middle exponential growth stage. The combination of MJ(0.02 mmol/L)and SA(0.03 mmol/L) also increased flavonoids production markedly, the flavonoids production reached 1125 mg/L at the prophase of exponential growth stage,which was 77.7 % higher than the control(633 mg/L). In addition the hairy root polysaccharide was extracted with hot water at 98℃ and with alkaloid at 98℃,then precipitated by alcohol. The protein in the extractions was removed by the sevage mathod. A α-Naphthol—sulphuric acid method was used for analyzing of the quality and quantity of the polysaccharide. The content of polysaccharide which was soluble in water was 2.453 % , the content of polysaccharide which was soluble in alkaloid was 3.391 %.