Study on active components of Andrographis paniculata at various growth periods and differential expression of key enzyme gene / 中草药

ABSTRACT

Objective: To study the dynamic changes of the active components from Andrographis paniculata at various growth periods grown in Suixi in Guangdong province, Zhangpu in Fujian province as well as introduced and cultivated in Nanjing and Huaian in Jiangsu province, and to investigate the expression level of the key enzyme gene at the same time in order to obtain the accumulation trend of the active contents from A. paniculata and explore a reasonable harvest and its molecular mechanism. Methods: The contents of andrographolide and dehydroandrographolide were analyzed by HPLC. The expression of key enzyme gene, ent-copalyl diphosphate synthase (CPS) was measured at mRNA level with QRT-PCR. Results: The growth periods of A. paniculata were similar in different areas. It grew fast at vegetative stage while slowly at reproductive stage. The contents of active ingredients in A. paniculata from four areas showed the same change tendency. The content of andrographolide reached the highest level at flowering period. At the same time, the changes of dehydroandrographolide was flatting out. The expression of CPS reached its maximum at bud to flowering period. There was a significant positive correlation between the content of andrographolide and the expression of CPS. Conclusion: The optimal harvest time of A. paniculata should be judged on phenological period and the best harvest period is flowering period.