Histochemical, micromorphology and ultrastructural investigation in glandular trichomes of Micromeria thymifolia

Abstract

Histochemical, micromorphology, ultrastructural and confocal analyses of the trichomes of Micromeria thymifolia (Scop.) Fritsch, were carried out using light microscopy, confocal laser scanning electron microscopy, scanning electron and transmission fluorescent microscopy. Three types of glandular trichomes - peltate, capitate and digitiform and non-glandular trichomes are described on the abaxial and adaxial leaf surface. Ultrastructural analyses showed the presence of mitochondria, plastids with lipid globules and proliferations of the granular endoplasmatic reticulum in secretory phases of the heads of glandular trichomes. The results of histochemical tests showed a positive reaction to polysaccharides, lipids and to some secondary compounds such as terpenes and phenols in different types of glandular trichomes. A strong red autofluorescence of the secreted material in glandular trichomes was observed with confocal laser scanning microscopy. © 2013 Institute of Botany and Botanical Garden Jevremovac, Belgrade.