@conference{
author = "Tošić, Svetlana and Stojičić, Dragana and Slavkovska, Violeta and Zlatković, Bojan and Budimir, Snežana and Uzelac, Branka",
year = "2017",
abstract = "Morphology and structure of Micromeria croatica glandular trichomes in relation to the secretory process were characterized using scanning electron microscopy (SEM) and light microscopy, and their secretion was histochemically analyzed. SEM and histochemical analysis revealed that leaf indumentum of in vitro grown M. croatica consisted of non-glandular and glandular trichomes (Figure 1a). The main types of glandular trichomes observed in M. croatica leaves were peltate and capitate (Figure 1b-d). Peltate trichomes consisted of a broad basal cell embedded in the epidermis, a single-celled stalk, and a large round multicellular head (Figure 1e, h). Two types of capitate trichomes, differing in size and structure, could be distinguished. Type I capitate trichomes were positioned at an angle to the leaf surface and composed of one basal epidermal cell, short cutinized stalk and unicellular ellipsoidal head (Figure 1f). Type II capitate trichomes comprised of one basal cell, unicellular stalk and one apical secretory cell (Figure 1g). Apical cell of mature type II capitate trichomes had well developed round subcuticular space (Figure 1d). Plant extracts secreted from glandular trichomes are a valuable source of biologically active compounds. Phytochemical analysis identified up to 37 compounds in the essential oils (EOs) of wild-growing and micropropagated plants, and revealed differences in both content and the composition of the EOs obtained from different samples. EOs from both native plant material and in vitro cultivated plants showed very high percentages of total monoterpenoids, dominated by oxygenated monoterpenes.
Borneol was the main essential oil component detected in wild-growing plants (25.28%) and micropropagated plants grown on plant growth regulator-free medium (20.30%). Micropropagated plants cultivated in the presence of 0.3 µM kinetin had the highest yield of the EO, with geranial (33.53%) and cis-p-mentha-1(7),8-dien-ol (23.69%) being the main EO components. The percentage of total sesquiterpenoids in micropropagated plant material was considerably lower than in wild-growing plants. Sesquiterpene hydrocarbons accounted for the majority of detected sesquiterpenoids and were dominated by alpha-cadinene and beta-vetivenene. Some of the volatiles were found only in plant material obtained by micropropagation but not in wild-growing plants. Differences in both content and the composition of the essential oils obtained from different samples indicated that in vitro culture conditions and plant growth regulators significantly influence the essential oils properties.",
publisher = "Zagreb: Ruđer Bošković Institute and Croatian Microscopy Society",
journal = "Book of Abstract: 13th Multinational Congress on Microscopy; 2017 Sep 24-29; Rovinj, Croatia",
title = "Glandular trichomes and essential oil characteristics of in vitro propagated Micromeria croatica (Pers.) Schott (Lamiaceae)",
pages = "302-303",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_6735"
}
