北柴胡分泌道的超微结构及其挥发油分泌的研究

利用透射电子显微镜技术研究了北柴胡营养器官中分泌道的发育以及挥发油的积累.并重点探讨了挥发油的分泌机制.结果显示.分泌道细胞的质体、细胞基质以及线粒体参与挥发油或其前体物质的合成,而内质网参与挥发油向分泌道腔隙的转运.在分泌道发育的后期,大量小泡与分泌细胞相邻壁的质膜融合,并将其内的物质释放入此部分细胞壁中,与此同时,此部分壁在靠近腔隙的位置结构变得松散.然后围绕腔隙的壁在相邻两分泌细胞相接的位置面向腔隙外突形成许多小泡,并将小泡释放入腔隙中.由此可见.北柴胡分泌道中挥发油主要以胞吐方式被排入分泌道的腔隙中.

ULTRASTRUCTURE AND SECRETION OF SECRETORY CANALS IN VEGETATIVE ORGANS OF BUPLEURUM CHINENSE DC

The development of secretory canals in vegetative organs of Bupleurum chinense DC.and the accumulation of essential oils were investigated by transmission electron microscopy (TEM)analysis.The secretion mechanism of the essential oil was also discussed.The results indicate that theplastid,ground substances of cytoplasm and mitochondria took part in the biosynthesis of oil or oil pre-cursor.The endoplasmic reticulum involved in the transport of essential oil to the secretory lumen.Atlatter stages of development of secretory cells,numerous different sized vesicles fused with the plas-malemma along the boundary between two neighbor secretory cells and secreted the substance into thewall. Thus.the wall between two neighbor secretory cells near the lumen became loosely structured.Then,the wall lined the lumen near two neighbor secretory cells extruded numerous grey vesicles withvarious sizes on the side facing the lumen,and released these vesicles into the lumen.As a result. themanner of secretion in secretory canals of Bupleurum chinense DC.appeared to be exocytosis.