Laboratory of Plant Anatomy and Morphology, Komarov Botanical Institute of the Russian Academy of Sciences, Professor Popov Street, 2, St. Petersburg, Russia, 197376.
Protoplasma. 2019 May;256(3):789-803. doi: 10.1007/s00709-018-01342-2. Epub 2019 Jan 2.
Two types of glandular tichomes (GTs) develop on the leaves in three Doronicum species. The purpose of the work was to establish common and distinctive morphological, anatomical, histochemical, and ultrustructural features of the trichomes. It turned out that differences between types of trichomes are more significant than interspecific ones. For each Doronicum species, differences between GTs of two types include the dimensions, intensity of coloration by histochemical dyes, as well as ultrastructural features of the cells. The GTs of the first type are higher than GTs of the second type. Two to three upper cell layers of the first trichomes develop histochemical staining, whereas in the second ones, only apical cells give a positive histochemical reaction. In all trichomes, polysaccharides, polyphenols, and terpenoids are detected. In the GTs of the first type, polysaccharides are synthesized in larger quantity; in the GTs of the second type, synthesis of the secondary metabolites predominates. Main ultrastructural features of the GTs of the first type include proliferation of RER and an activity of Golgi apparatus denoting the synthesis of enzymes and pectin; however, development of SER, diversiform leucoplasts with reticular sheaths, and chloroplasts with peripheral plastid reticulum also demonstrate the synthesis of lipid substances. The ultrastructural characteristics of the second type GTs indicate the primary synthesis of lipid components. Secretion is localized in a periplasmic space of the upper cell layers. The secretory products pass through the cell wall, accumulate in the subcuticular cavity, and rupture it.
三种款冬属植物叶片上发育出两种腺毛 (GTs)。本工作旨在确定毛状体的形态、解剖、组织化学和超微结构特征的共同和独特之处。结果表明，毛状体类型之间的差异比种间差异更为显著。对于每种款冬属植物，两种类型的 GTs 之间的差异包括细胞的尺寸、组织化学染料着色的强度以及超微结构特征。第一类 GTs 比第二类 GTs 高。第一类毛状体的 2 到 3 个上层细胞层发生组织化学染色，而在第二类毛状体中，只有顶端细胞呈阳性组织化学反应。在所有毛状体中，均检测到多糖、多酚和萜类化合物。在第一类 GTs 中，多糖的合成量较大；在第二类 GTs 中，次生代谢物的合成占主导地位。第一类 GTs 的主要超微结构特征包括 RER 的增殖和高尔基体的活性，表明酶和果胶的合成；然而，SER 的发育、具有网状鞘的多样白色体和具有周边质体网的叶绿体也表明了脂质物质的合成。第二类 GTs 的超微结构特征表明了脂质成分的初步合成。分泌物定位于上层细胞的周质空间。分泌产物穿过细胞壁，在表皮下腔中积累，并使其破裂。
