[Accumulation and localization of camptothecin in young shoot of Camptotheca acuminata].

The developmental of young stems and leaves were investigated using optical, fluorescence and scanning electron microscopy and the camptothecin content in Camptotheca acuminata was analyzed by HPLC. Secretory structure, especially secretory canals were found. A linear relationship (r(2)=0.9257) was found between CPT content and secretory canal density of stem. The secretion in canals and glandular trichomes showed intense blue autofluorescence under 360 nm UV light. The results showed that camptothecin was primarily accumulated in glandular trichomes and secretory canals of stems and leaves.