Development and Structure of Internal Glands and External Glandular Trichomes in Pogostemon cablin (original) (raw)
Figure 1
The development and histochemistry of internal glands in leaves.
(A)The images (SEM) of Pogostemon cablin leaves showing the internal gland (arrow) among palisade cells. (B) The semithin section of leaves showing the morphology of internal gland. (C–F) Semithin sections of internal glands in different developmental phases showing the developmental process: (C) the initial cell of internal glands with the nucleus (arrow); (D) the initial cell with a vacuolate basal cell and a apical cell after apericlinal cell division (arrows); (E) internal glands at three-celled stage with twocytoplasmically dense cells after the apical cell divisions (arrows); (F) mature internal glands with one big secretory cell, one narrow stalk cell and one vacuolate basal cell. (G–L) Bright field and fluorescence micrographs of internal glands in leaves showing histochemical characterization of secretory products. Secretory material reacts positively for total lipids with Neutral Red (G), Sudan III (H) and Sudan Black B (I). The reaction for unsaturated lipids using OsO4 (J) is positive. The essential oil within the sub-cuticular space has reacted positively with the Nadi reagent for terpenes (K). And the staining for flavones with Naturstoffreagent A suggests the presence of flavones in the internal glands of leaves (L).