贯叶金丝桃叶中分泌细胞团的超微结构

随着贯叶金丝桃（Hypericum perforatum L.)叶中分泌细胞团的发育，其细胞中质体的数量和体积逐渐增大，但一些质体局部出现解体，大量的深色管状结构和小泡出现在退化质体的周围，有些小泡与液泡融合，并将其内容物释放至液泡中，导致液泡中出现大量的多泡结构，多膜结构和嗜锇滴。同时，高尔基体分泌小泡进入液泡。然而，当分泌细胞团发育成熟后，分泌细胞被含有灰色均匀的分泌物（金丝桃素）的大液泡所占据，嗜锇滴消失。表明嗜锇滴可能是金丝桃素的前体物，来源于退化的质体。出现于质体和嗜锇滴之间的内质网和高尔基体可能也参与了金丝桃素前体物的合成和细胞内的转运。

Ultrastructure of the Multicellular Nodules in Hypericum perforatum Leaves

With the development of the multicellular nodules in the leaves of Hypericum perforatum L., plastids increased both in number and volume, and some plastids degenerated and were surrounded by dark tubular elements and vesicles. Some vesicles fused with vacuoles and secreted substances into vacuoles. There are many multivesicles, multimembrane structures and osmiophilic droplets in vacuoles of nodule cells. Meanwhile, dictyosome secreted vesicles into the vacuoles. However, there is a large central vacuole completely filled with secretory materials (hypericin) in matured multicellular nodules. This suggests that the osmiophilic droplets may be a precursor of hypericin originated from the degenerated plastids. There were abundant endoplasmic reticulums and dictyosomes between the plastids and osmiophilic droplets, suggesting that they may be involved in the synthesis and/or transport of the precursor of hypericin.