Distribution of camptothecin and its metabolism-related enzymes in Camptotheca acuminata seedlings

Objective To investigate the distribution of camptothecin(CPT),tryptophan synthase(TSB),and tryptophan decarboxylase(TDC) in Camptotheca acuminata seedlings.Methods The CPT content,TSB and TDC activities in different organs of C.acuminata seedlings subjected to different nitrogen forms treatments by sand culture in greenhouse were determined by HPLC.Results The CPT content in the young leaves of C.acuminata seedlings with different N-forms was significantly higher than that in other organs(P0.01),then in the stem barks and the mature leaves,and the lowest in the roots.Under different N-forms,TSB activity was the highest in the young leaves,and decreased sequentially in the stem barks,the mature leaves,and the roots,which paralleled to CPT content.TDC activity was the highest in the stem barks of the seedlings with different N-forms,then in the young leaves,and the lowest in the mature leaves and the roots,which didn't parallel to CPT content.Conclusion CPT Content,TSB and TDC activities present differently in various organs of C.acuminata seedlings.CPT Content and TSB activity are the highest in the young leaves,TDC activity is the highest in the stem barks among the organs.