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Development, oil storage and dehiscence of peltate trichomes in Thymus vulgaris (Lamiaceae)
Author(s) -
Bruni Alessandro,
Modenesi Paolo
Publication year - 1983
Publication title -
nordic journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.333
H-Index - 33
eISSN - 1756-1051
pISSN - 0107-055X
DOI - 10.1111/j.1756-1051.1983.tb01073.x
Subject(s) - trichome , primordium , biology , botany , cuticle (hair) , polysaccharide , ultrastructure , essential oil , lamiaceae , microbiology and biotechnology , secretion , anatomy , biochemistry , gene
The development, oil storage and dehiscence mechanism of the peltate oil–producing trichome in Thymus vulgaris L. was studied by conventional, fluorescence and electron scanning microscopy. A single epidermal initial forms the glandular trichome whose primordium becomes distinguishable from non–glandular trichomes at its 3–celled stage. The further divisions determine the formation of three functional compartments, (a) a basal reservoir cell, (b) an “endodermal” cell, and (c) a group of secretory head cells. At first, the gland head shows a bowl–like shape with a folded cuticular covering that raises successively assuming a dome–like form. During the differentiation of the gland cells, histochemical tests reveal the occurrence of a precise sequence of metabolic events: synthesis of RNA, proteins, glycoproteins, polysaccharides and, finally osmiophilic substances. At maturity, the cuticular sheath is formed by a non–cellulosic polysaccharide framework on which the cuticle is deposed. Proceeding towards the senescence, the polysaccharide framework disappears and a large crescent shaped pore forms, whereby essential oils are released. Collected results are discussed in order to interpret gland function and essential oil production.