Convergence of glandular trichome morphology and chemistry in two montane monkeyflower species

Abstract

11Two distantly-related North American montane monkeyflower species, Mimulus lewisii and 12 Mimulus tilingii, possess glandular trichomes. In this study, we characterized the 13 morphological and histochemical features of these glandular trichomes. For each species, we 14 used traditional light microscopy and scanning electron microscopy (SEM) to examine 15 morphological characteristics, and determined the main components of the secretory products 16 using histochemical and thin layer chromatography (TLC) staining techniques. We identified 17 type VI glandular trichomes on leaf surfaces in both species of monkeyflowers. These 18 trichomes exhibited stalk-cell lengths and head-cell counts that varied across adaxial and 19 abaxial leaf surfaces, stems, and sepals. Both species contained secretory products within the 20 cuticle of the trichome head, which releases the subcuticular metabolites when ruptured. 21 Histochemical tests in both M. lewisii and M. tilingii confirmed that secretions contained 22 lipids and polysaccharides. TLC plate staining indicated the presence of UV active 23 compounds with polyalcohols, lipids, and amines. The common morphology and chemistry 24 of the glandular trichomes suggests an analogous response to similar environmental 25 conditions in these evolutionary distant montane monkeyflowers. 26 27

A method for the identification and evaluation of Glycyrrhiza germplasm based on DNA barcodes and leaf micromorphology

“…However, this study detected bristles in the lower leaf epidermis in all tested species and hybrids, and glandular trichomes were more or less present in all other species and hybrids except for G. prostrata (moniliform pod species). Trichomes can control transpiration, improve frost tolerance, and protect tissues from UV damage and extreme temperatures, and glandular trichomes, which synthesize, store, or secrete a variety of bioactive metabolites, such as terpenes, phenylpropion, aliphates, alkaloids, and acyl sugars, affect rodents' predation, pollination, seed dispersion, and interplant signaling (Eguiguren et al, 2020;Mershon et al, 2015;Schilmiller et al, 2008). There are a large number of glandular trichomes in the epidermis of Glycyrrhiza plant leaves, and the components and functions of the secretions need to be further studied.…”

The effect of organic fertilizers on the leaf morphology and stomatal density of Pogostemon cablin Benth

“…The morphology, function and density of the trichomes are varies among the plant species. There are two types of trichomes; glandular that able to excreting the secondary metabolite such as patchouli oil and non-glandular trichomes with has not able to do the mentioned function [17]. The essential oils produced from glandular trichome has function in protecting plants from the herbivore and pathogens [18]…”