喜树的分泌结构及其与喜树碱积累的关系

为了揭示喜树碱(camptothecin,CPT)在喜树(Camptotheca acuminata Decne.)中的积累部位及积累规律,运用组织化学技术和高效液相色谱技术对喜树茎、叶中喜树碱的积累部位和含量进行了相关性分析.结果发现两类分泌结构与喜树碱积累密切相关:一类是分布于幼茎和幼叶表面的单细胞腺毛;另一类是分布于喜树幼茎和幼叶中的由1～2层细胞包围而成的分泌道.由此推断,喜树中的分泌结构为喜树碱的主要积累部位.

Secretory Structures and Their Relationship to Accumulation of Camptothecin in Camptotheca acuminata (Nyssaceae)

Camptotheca acuminata Decne. (Nyssaceae) is a major source of the anticancer camptothecin (CPT). It is important to understand how CPT accumulates in C. acuminata in order to improve CPT production strategies. The aim of this study was to anatomically and morphologically characterize the secretory structure in leaves and stems of C. acuminata and determine their relationship to accumulation of CPT. Secretory canals and glandular trichomes were found in young stems and young leaves. Secretory canals consisted of a sub-epidermal canal delimited by one to two layers of cells. Glandular trichomes were unicellular. Fluorescence microscopy and CPT analysis showed that CPT was primarily accumulated in secretory canals and glandular trichomes of leaves and stems.