Muravnik Lyudmila E, Kostina Olga V, Shavarda Alexey L
Laboratory of Plant Anatomy and Morphology, Komarov Botanical Institute of Russian Academy of Sciences, Professor Popov Street, 2, 197376, St. Petersburg, Russia.
Laboratory of Analytical Phytochemistry, Komarov Botanical Institute of Russian Academy of Sciences, Professor Popov Street, 2, 197376, St. Petersburg, Russia.
Planta. 2016 Sep;244(3):737-52. doi: 10.1007/s00425-016-2539-x. Epub 2016 May 5.
The glandular trichomes are developed on the aerial organs of Tussilago farfara ; they produce phenols and terpenoids. Smooth endoplasmic reticulum and leucoplasts are the main organelles of the trichome secretory cells. The aim of this study was to characterise the morphology, anatomy, histochemistry and ultrastructure of the trichomes in Tussilago farfara as well as to identify composition of the secretory products. Structure of trichomes located on the peduncles, bracts, phyllaries, and leaves were studied by light and electron microscopy. The capitate glandular trichomes consist of a multicellular head and a biseriate long stalk. Histochemical tests and fluorescence microscopy reveal phenols and terpenoids in the head cells. During secretory stage, the head cells contain smooth and rough endoplasmic reticulum, Golgi apparatus, diversiform leucoplasts with opaque contents in lamellae, chloroplasts, mitochondria, and microbodies. In the capitate glandular trichomes of T. farfara subcuticular cavity is absent, unlike glandular trichomes in other Asteraceae species. For the first time, content of metabolites in the different vegetative and reproductive organs as well as in the isolated capitate glandular trichomes was identified by GC-MS. Forty-five compounds, including organic acids, sugars, polyols, phenolics, and terpenoids were identified. It appeared that metabolite content in the methanol extracts from peduncles, bracts and phyllaries is biochemically analogous, and similar to the metabolites from leaves, in which photosynthesis happens. At the same time, the metabolites from trichome extracts essentially differ and refer to the above-mentioned secondary substances. The study has shown that the practical value of the aerial organs of coltsfoot is provided with flavonoids produced in the capitate glandular trichomes.
款冬的地上器官上着生有腺毛；它们能产生酚类和萜类化合物。光滑内质网和白色体是腺毛分泌细胞的主要细胞器。本研究的目的是描述款冬腺毛的形态、解剖结构、组织化学和超微结构，并鉴定其分泌产物的成分。通过光学显微镜和电子显微镜研究了花茎、苞片、总苞片和叶片上腺毛的结构。头状腺毛由多细胞的头部和双列的长柄组成。组织化学测试和荧光显微镜显示头部细胞中含有酚类和萜类化合物。在分泌阶段，头部细胞含有光滑内质网和粗糙内质网、高尔基体、含有不透明内容物的各种白色体、叶绿体、线粒体和微体。与其他菊科植物的腺毛不同，款冬的头状腺毛皮下腔不存在。首次通过气相色谱-质谱联用仪鉴定了不同营养器官和生殖器官以及分离出的头状腺毛中代谢产物的含量。鉴定出45种化合物，包括有机酸、糖类、多元醇、酚类和萜类化合物。结果表明，花茎、苞片和总苞甲醇提取物中的代谢产物在生化性质上相似，且与进行光合作用的叶片中的代谢产物相似。同时，腺毛提取物中的代谢产物与上述次生代谢物有本质区别。研究表明，款冬地上器官的实用价值在于头状腺毛中产生的黄酮类化合物。
