Effects of water stress and nitrogen nutrition on regulation of Catharanthus roseus alkaloids metabolism

OBJECTIVE: Under various drought conditions and nitrogen application, the content of vindoline, catharanthine, vincristine and vinblastine in the leaf of Catharanthus roseus were illustrated to improve the content of alkaloid theoretically. METHOD: Six groups were set in the experiment, which included: CK (natural control), CN (natural control + nitrogen), LK (low drought), LN (low drought + nitrogen), HK (high drought), HN (high drought + nitrogen) to discuss the change characteristics of total nitrogen, the activity of alkaline POD and TDC, the content of four alkaloids under the different conditions were measured. RESULT: Under LK condition, the activity of POD, TDC were enhanced. In the early stage of stress (0-21 d), vindoline, catharanthine, vincristine and vinblastine accumulated, and reduced in the later stage (28-35 d). For all groups, adding exogenous nitrogen could improve the total content of nitrogen, vindoline and vinblastine, meanwhile the activity of POD and TDC were enhanced as well. The LN, HN treatments were beneficial to accumulating catharanthine and vinblastine. CONCLUSION: Drought stress or additional nitrogen have an influence on both of the activities of POD and TDC, and the four alkaloids were affected as well. Thereinto, the LN condition was the most effective treatment for accumulating the four alkaloids (vindoline, catharanthine, vincristine and vinblastine), which were regulated by improve nitrogen content and enzymatic activity.