title: Morphogenesis and developmental ultrastructure of Nicotiana tabacum short glandular trichomes.
abstract: The anatomy and ultrastructure of the short glandular trichomes occurring on young expanding leaves of Nicotiana tabacum were investigated using light and transmission electron microscopy. The objective of the present research was to characterize the cellular changes that occur during morphogenesis of short glandular trichomes, from initiation to senescence. Ultrastructural analysis of their secretory cells revealed characteristics common to gland cells: numerous mitochondria in highly organized cytoplasm, large nuclei, and an elaborate network of endoplasmic reticulum. Initial changes in nuclear and plastidial organization were observed at a more advanced secretory stage, marking the onset of senescence. During trichome senescence, gradual reduction of the cytoplasm density occurred along with structural changes of the plastids and the tonoplast. As a result of inward blebbing of the cytoplasm into the vacuole, membrane bound vesicular structures appeared in the vacuolar space. At the late secretory stage, marked by an increase in vacuolation and extraplasmic space, degenerative changes included further fragmentation of the cytoplasm and deterioration of the tonoplast. Multimembrane myelin bodies observed in the vacuolar space were indicative of membrane digestion although plasma membrane did not appear massively degraded.
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia.
authors.forename: Branka
authors.identifier: http://orcid.org/0000-0002-1332-1626
authors.initials: B
authors.lastname: Uzelac
authors.affiliation: Faculty of Biology, Institute of Botany and Botanical Garden "Jevremovac", University of Belgrade, Takovska 43, Belgrade, 11000, Serbia.
authors.forename: Dušica
authors.initials: D
authors.lastname: Janošević
authors.affiliation: Faculty of Science, University of Niš, Višegradska 33, Niš, 18000, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Stojičić
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, Belgrade, 11060, Serbia.
authors.forename: Snežana
authors.initials: S
authors.lastname: Budimir
mesh_terms: D002462:Cell Membrane / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009024:Morphogenesis; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000166:cytology / Q000648:ultrastructure; D014026:Nicotiana / Q000033:anatomy & histology* / Q000254:growth & development; D064201:Trichomes / Q000502:physiology* / Q000648:ultrastructure*
keywords: gland senescence; tobacco; transmission electron microscopy; trichome development