Study On Establishment Of Cell Suspension Culture System Of Camptotheca Acuminate And Regulation Of Camptothecin Content

Using cell suspension culture to enhance the contents of plant secondary metabolites is a new method in production of some secondary metabolites. Camptothecin(CPT) is an important metabolite in Camptotheca acuminate, because of its anti-cancer activity. The general steps for CPT production by cell culture method are as follows:callus induction→subculture→cell suspension culture→expanding culture. In this study, young leaves and stems of Camptotheca acuminate were used as the materials to investigate callus induction, subculture of the callus and cell suspension culture of Camptotheca acuminate. By adding different elicitors such as sucrose, BR and UV treatment during cell suspension culture, the influences of the elicitors on the cell growth and CPT contents of Camptotheca acuminate were examined for the industrialization of using cell suspension culture to produce secondary metabolites.Study on callus induction and subculture of the callus of Camptotheca acuminate showed that different kinds, concentration and combinations of plant growth substances had different effects on cell growth. The most suitable medium for callus induction was SH with 2.0 mg/L NAA and 0.5 mg/L 6-BA, and the callus inducing rate was 92%. MS medium with 2.0 mg/L 6-BA and 0.5 mg/L NAA was found to be the best subculture medium formula. The acquired callus induced under the above conditions is loose texture and suitable for cell suspension culture. The cell suspension culture system was established with MS medium with 2.0 mg/L 6-BA and 0.5 mg/L NAA and 3% sucrose. Cell suspension culture growth curve was the "S" shape; and the pH value decreases first and then increases, and soluble protein content and peroxidase activity were appeared of two peaks. It is found that different concentrations of sucrose, BR and UV treatment have some effects on cell suspension culture of Camptotheca acuminate growth and the content of CPT. Among the above three factors, adding 0.005mg/L BR shows the most significant effect on the yield of CPT-about 83.37μg/gDW, increasing 4 times of the yield compared with no BR addition. However. this yield is still lower than the intact plant.