Analysis of trichome morphology and density in Salvia nemorosa L. (Lamiaceae) of Iran

AbstractSalvia nemorosa L. is an aromatic herb distributed widely in various regions of Iran, and is used in traditional and modern medicine. In the present study, leaf trichome densities and also type were investigated in six populations of the species, because the effective substances of this species exist in essential oil of glandular trichomes. For this, the mature intact leaves of each population were fixed in FAA solution, and then transverse hand sections were double-stained and studied using light microscopy. Leaf indumentum in all of the populations was dense pilose, with the exception of Tehran population that had loose pilose. Thirteen kinds of trichomes were identified, the main of which were peltate and capitate. PCA-biplot showed that each of these populations had prominent trichome trait(s). Furthermore, significant positive/negative correlations were found between some trichome types with main ecological factors of habitat. The studied populations clustered separately in the UPGMA tree, moreover, PCA and also PCO plots produced similar results. Our findings confirmed that ecological parameters of a habitat have strong effects on trichome morphology and density.

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Histochemical and Phytochemical Analysis of Lamium album subsp. album L. Corolla: Essential Oil, Triterpenes, and Iridoids

Molecules ◽

10.3390/molecules26144166 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4166

Author(s):

Agata Konarska ◽

Elżbieta Weryszko-Chmielewska ◽

Anna Matysik-Woźniak ◽

Aneta Sulborska ◽

Beata Polak ◽

...

Keyword(s):

Essential Oil ◽

High Performance ◽

Glandular Trichomes ◽

Gas Chromatography Mass Spectrometry ◽

Phytochemical Analysis ◽

Lipophilic Compounds ◽

Histochemical Tests ◽

Microscopy Techniques ◽

Trichome Types ◽

First Time

The aim of this study was to conduct a histochemical analysis to localize lipids, terpenes, essential oil, and iridoids in the trichomes of the L. album subsp. album corolla. Morphometric examinations of individual trichome types were performed. Light and scanning electron microscopy techniques were used to show the micromorphology and localization of lipophilic compounds and iridoids in secretory trichomes with the use of histochemical tests. Additionally, the content of essential oil and its components were determined using gas chromatography-mass spectrometry (GC-MS). Qualitative analyses of triterpenes carried out using high-performance thin-layer chromatography (HPTLC) coupled with densitometric detection, and the iridoid content expressed as aucubin was examined with spectrophotometric techniques. We showed the presence of iridoids and different lipophilic compounds in papillae and glandular and non-glandular trichomes. On average, the flowers of L. album subsp. album yielded 0.04 mL/kg of essential oil, which was dominated by aldehydes, sesquiterpenes, and alkanes. The extract of the L. album subsp. album corolla contained 1.5 × 10−3 ± 4.3 × 10−4 mg/mL of iridoid aucubin and three triterpenes: oleanolic acid, β-amyrin, and β-amyrin acetate. Aucubin and β-amyrin acetate were detected for the first time. We suggest the use of L. album subsp. album flowers as supplements in human nutrition.

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Petal and Sepal Epidermal Micromorphology of Six Lathyrus Taxa (Fabaceae) and their Systematic Value

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha4017503 ◽

2012 ◽

Vol 40 (1) ◽

pp. 35 ◽

Cited By ~ 8

Author(s):

HÃ¼seyin CILDIR ◽

Ahmet KAHRAMAN ◽

Musa DOGAN

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Light Microscopy ◽

Glandular Trichomes ◽

Systematic Significance ◽

Trichome Types ◽

First Time ◽

Scanning Electron

In this study, the epidermal types and their distribution on dorsal and lateral petals, the trichome types and their density on sepals of Lathyrus chloranthus, L. digitatus, L. laxiflorus subsp. laxiflorus, L. roseus subsp. roseus, L. sativus, and L. tuberosus, belonging to sections Lathyrus, Lathyrostylis, Pratensis, and Orobon of the genus Lathyrus in Turkey were investigated using light microscopy (LM) and scanning electron microscopy (SEM), and the systematic significance of these characters was evaluated. These taxa, except L. sativus, are studied for the first time under aspects of the petal and sepal micromorphology. Three major epidermal types were recognized on the petal: tabular rugose striate cells (TRS), areolate cells with more or less striations (AS), and papillose conical striate cells (PCS). TRS and AS were further subdivided into three subtypes. TRS was found on the dorsal and lateral petals of L. chloranthus, L. sativus, and L. tuberosus: the dorsal petals of L. roseus subsp. roseus and the lateral petals of L. laxiflorus subsp. laxiflorus, while AS was present on the dorsal and lateral petals of L. digitatus and the lateral petals of L. roseus subsp. roseus. PCS was found only on the dorsal petals of L. digitatus. Three main types of trichomes on the sepal were observed: peltate glandular, capitate glandular, and nonglandular trichomes. The capitate glandular and nonglandular trichomes were further subdivided into three subtypes. The peltate glandular trichomes were present only in L. chloranthus, but absent in the others. The capitate glandular trichomes were found in L. chloranthus, L. laxiflorus subsp. laxiflorus, L. roseus subsp. roseus, and L. tuberosus. The nonglandular trichomes were always present in L. chloranthus and L. laxiflorus subsp. laxiflorus. The present results show that the petal and sepal micromorphology can be used in delimitation of the taxa based on petal and sepal micromorphology.

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Leaf trichomes of Portuguese Lavandula species: a comparative morphological study

Microscopy and Microanalysis ◽

10.1017/s143192760999064x ◽

2009 ◽

Vol 15 (S3) ◽

pp. 37-38 ◽

Cited By ~ 3

Author(s):

M. R. Zuzarte ◽

A. M. Dinis ◽

J. Canhoto ◽

L. Salgueiro

Keyword(s):

Morphological Study ◽

Glandular Trichomes ◽

Economic Value ◽

Aromatic Plants ◽

Aerial Parts ◽

Different Types ◽

Leaf Trichome ◽

Trichome Morphology ◽

High Diversity ◽

Scanning Electron

AbstractLavandula species are aromatic plants that produce and accumulate essential oils in different types of glandular trichomes. The oils protect the aerial parts of the plant against herbivores and pathogens, and are of great economic value for fragrance, pharmaceutical, food and flavour industries. In Portugal there are five spontaneous species of Lavandula which are included in three different sections: Section Lavandula (L. latifolia), Section Pterostoechas (L. multifida) and Section Stoechas (L. luisieri, L. pedunculata, L. viridis). Our preliminary observations showed that these species have a high diversity of trichomes. This, associated with the fact that trichome morphology is often referred as an useful characteristic for systematic purposes, led us to investigate leaf trichome morphology in the five Portuguese species, using scanning electron microscopy (SEM).

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Evolution of trichome morphology in Mimosa (Leguminosae-Mimosoideae)

Phytotaxa ◽

10.11646/phytotaxa.119.1.1 ◽

2013 ◽

Vol 119 (1) ◽

pp. 1 ◽

Cited By ~ 6

Author(s):

JULIANA SANTOS-SILVA ◽

ANA MARIA GOULART DE AZEVEDO TOZZI ◽

MARCELO FRAGOMENI SIMON ◽

NAZARETH GUEDES URQUIZA ◽

MATÍAS MORALES

Keyword(s):

Glandular Trichomes ◽

Character State ◽

Optimization Analysis ◽

Ancestral Character State ◽

History Of ◽

Ancestral Character State Reconstruction ◽

Species Groups ◽

Trichome Types ◽

Trichome Morphology ◽

Insight Into

With more than 500 species, Mimosa L. is one of the largest genera of the Leguminosae. It exhibits considerable trichome diversity among species. Trichome types have been used as diagnostic characters, but some are not well known and have been poorly described in taxonomic works, causing some difficulties for species identification and description. The morphology of trichomes of 35 species was studied using scanning electron microscopy and light microscopy to define the types of trichomes precisely. An ancestral character state reconstruction using a densely-sampled phylogeny of the genus was performed in order to investigate the evolution of trichome types in Mimosa. Two basic types of trichomes can be distinguished: glandular and non-glandular. The glandular trichomes can be sessile or stalked. The non-glandular trichomes can be unbranched or branched. Unbranched trichomes are unicellular and conical or cylindrical, whereas branched trichomes are multicellular and verruciform, medusiform, plumose, barbellate, stellate, stellate-lepidote, or lepidote. Character optimization analysis suggests that glandular and branched trichomes are derived and evolved independently in different lineages within Mimosa. The ancestral condition in Mimosa was probably non-glandular and unbranched trichomes, which was retained from piptadenioid ancestors. Our study provides a first insight into the evolutionary history of trichome morphology in the genus. Despite high levels of homoplasy, trichome morphology offers a set of characters that can be used for differentiating species and species groups in combination with other characters.

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Introgression of the sesquiterpene biosynthesis from Solanum habrochaites to cultivated tomato offers insights into trichome morphology and arthropod resistance

Planta ◽

10.1007/s00425-021-03651-y ◽

2021 ◽

Vol 254 (1) ◽

Author(s):

Rodrigo Therezan ◽

Ruy Kortbeek ◽

Eloisa Vendemiatti ◽

Saioa Legarrea ◽

Severino M. de Alencar ◽

...

Keyword(s):

Glandular Trichomes ◽

Pest Resistance ◽

Chromosome 8 ◽

Cavity Size ◽

Solanum Habrochaites ◽

Genetic Components ◽

Internal Storage ◽

In The Wild ◽

Low Levels ◽

Trichome Morphology

Abstract Main conclusion Cultivated tomatoes harboring the plastid-derived sesquiterpenes from S. habrochaites have altered type-VI trichome morphology and unveil additional genetic components necessary for piercing-sucking pest resistance. Abstract Arthropod resistance in the tomato wild relative Solanum habrochaites LA1777 is linked to specific sesquiterpene biosynthesis. The Sesquiterpene synthase 2 (SsT2) gene cluster on LA1777 chromosome 8 controls plastid-derived sesquiterpene synthesis. The main genes at SsT2 are Z-prenyltransferase (zFPS) and Santalene and Bergamotene Synthase (SBS), which produce α-santalene, β-bergamotene, and α-bergamotene in LA1777 round-shaped type-VI glandular trichomes. Cultivated tomatoes have mushroom-shaped type-VI trichomes with much smaller glands that contain low levels of monoterpenes and cytosolic-derived sesquiterpenes, not presenting the same pest resistance as in LA1777. We successfully transferred zFPS and SBS from LA1777 to cultivated tomato (cv. Micro-Tom, MT) by a backcrossing approach. The trichomes of the MT-Sst2 introgressed line produced high levels of the plastid-derived sesquiterpenes. The type-VI trichome internal storage-cavity size increased in MT-Sst2, probably as an effect of the increased amount of sesquiterpenes, although it was not enough to mimic the round-shaped LA1777 trichomes. The presence of high amounts of plastid-derived sesquiterpenes was also not sufficient to confer resistance to various tomato piercing-sucking pests, indicating that the effect of the sesquiterpenes found in the wild S. habrochaites can be insect specific. Our results provide for a better understanding of the morphology of S. habrochaites type-VI trichomes and paves the way to obtain insect-resistant tomatoes.

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Transcriptome Analysis of Light-Regulated Monoterpenes Biosynthesis in Leaves of Mentha canadensis L.

Plants ◽

10.3390/plants10050930 ◽

2021 ◽

Vol 10 (5) ◽

pp. 930

Author(s):

Xu Yu ◽

Xiwu Qi ◽

Shumin Li ◽

Hailing Fang ◽

Yang Bai ◽

...

Keyword(s):

Essential Oil ◽

Transcriptome Analysis ◽

Average Length ◽

Glandular Trichomes ◽

Signal Transduction Pathway ◽

Glandular Trichome ◽

Light Treatment ◽

Light Signal ◽

Environmental Aspect ◽

Underlying Mechanisms

Light is a key environmental aspect that regulates secondary metabolic synthesis. The essential oil produced in mint (Mentha canadensis L.) leaves is used widely in the aromatics industry and in medicine. Under low-light treatment, significant reductions in peltate glandular trichome densities were observed. GC-MS analysis showed dramatically reduced essential oil and menthol contents. Light affected the peltate glandular trichomes’ development and essential oil yield production. However, the underlying mechanisms of this regulation were elusive. To identify the critical genes during light-regulated changes in oil content, following a 24 h darkness treatment and a 24 h recovery light treatment, leaves were collected for transcriptome analysis. A total of 95,579 unigenes were obtained, with an average length of 754 bp. About 56.58% of the unigenes were annotated using four public protein databases: 10,977 differentially expressed genes (DEGs) were found to be involved in the light signaling pathway and monoterpene synthesis pathway. Most of the TPs showed a similar expression pattern: downregulation after darkness treatment and upregulation after the return of light. In addition, the genes involved in the light signal transduction pathway were analyzed. A series of responsive transcription factors (TFs) were identified and could be used in metabolic engineering as an effective strategy for increasing essential oil yields.

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Multi-omics analysis of the bioactive constituents biosynthesis of glandular trichome in Perilla frutescens

BMC Plant Biology ◽

10.1186/s12870-021-03069-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Peina Zhou ◽

Mengjiao Yin ◽

Shilin Dai ◽

Ke Bao ◽

Chenglin Song ◽

...

Keyword(s):

Glandular Trichomes ◽

Glandular Trichome ◽

Perilla Frutescens ◽

Morphological Features ◽

Limited Information ◽

Bioactive Constituents ◽

Edible Plant ◽

Cell Factories ◽

Custom Made ◽

Trichome Types

Abstract Background Perilla frutescens (L.) Britt is a medicinal and edible plant widely cultivated in Asia. Terpenoids, flavonoids and phenolic acids are the primary source of medicinal ingredients. Glandular trichomes with multicellular structures are known as biochemical cell factories which synthesized specialized metabolites. However, there is currently limited information regarding the site and mechanism of biosynthesis of these constituents in P. frutescens. Herein, we studied morphological features of glandular trichomes, metabolic profiling and transcriptomes through different tissues. Results Observation of light microscopy and scanning electron microscopy indicated the presence of three distinct glandular trichome types based on their morphological features: peltate, capitate, and digitiform glandular trichomes. The oil of peltate glandular trichomes, collected by custom-made micropipettes and analyzed by LC–MS and GC–MS, contained perillaketone, isoegomaketone, and egomaketone as the major constituents which are consistent with the components of leaves. Metabolomics and transcriptomics were applied to explore the bioactive constituent biosynthesis in the leaves, stem, and root of P. frutescens. Transcriptome sequencing profiles revealed differential regulation of genes related to terpenoids, flavonoids, and phenylpropanoid biosynthesis, respectively with most genes expressed highly in leaves. The genes affecting the development of trichomes were preliminarily predicted and discussed. Conclusions The current study established the morphological and chemical characteristics of glandular trichome types of P. frutescens implying the bioactive constituents were mainly synthesized in peltate glandular trichomes. The genes related to bioactive constituents biosynthesis were explored via transcriptomes, which provided the basis for unraveling the biosynthesis of bioactive constituents in this popular medicinal plant.

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Glandular trichomes and essential oil constituents ofCalamintha menthifolia (Lamiaceae)

Plant Systematics and Evolution ◽

10.1007/bf00937823 ◽

1991 ◽

Vol 177 (1-2) ◽

pp. 17-26 ◽

Cited By ~ 36

Author(s):

E. Hanlidou ◽

S. Kokkini ◽

A. M. Bosabalidis ◽

J. -M. Bessi�re

Keyword(s):

Essential Oil ◽

Glandular Trichomes

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Changes in Structure and Histochemistry of Glandular Trichomes ofThymus quinquecostatusCelak

The Scientific World JOURNAL ◽

10.1100/2012/187261 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 8

Author(s):

Ping Jia ◽

Ting Gao ◽

Hua Xin

Keyword(s):

Essential Oil ◽

Secretory Pathway ◽

Development Process ◽

Glandular Trichomes ◽

Capitate Trichomes ◽

Different Types ◽

Distribution Structure ◽

Distinctive Difference ◽

Subcuticular Space ◽

Three Components

The types, morphology, distribution, structure, and development process of the glandular trichomes on the leaves ofThymus quinquecostatusCelak had been investigated in this study. Two different types of glandular trichomes were determined in detail, namely, capitate trichomes and peltate ones. Besides, there were distinct differences on morphology, distribution, structure, and development process between the two kinds of trichomes. As the peltate trichome stepping into senium stage, it caved in the epidermis integrally, which was different from the capitate one. The secretion of the capitate trichome contained essential oil, polyphenols, and flavonoids, while, in addition to these three components, the secretion of the peltate one also contained acid polysaccharides. A distinctive difference was also seen in the secretory pathway of the secretion between the two types of trichomes. The secretion of capitate one was extruded through the cuticle of the head cell, but the secretion of the peltate one kept accumulating in the subcuticular space of the head cells until it was released by cuticle rupture.

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Valorization of CBD-hemp through distillation to provide essential oil and improved cannabinoids profile

Scientific Reports ◽

10.1038/s41598-021-99335-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Valtcho D. Zheljazkov ◽

Filippo Maggi

Keyword(s):

Essential Oil ◽

Steam Distillation ◽

Cannabis Sativa ◽

Plant Biomass ◽

Glandular Trichomes ◽

Gas Chromatography Mass Spectrometry ◽

Simple Method ◽

Certified Organic ◽

Secondary Hypothesis ◽

Epidermal Membrane

AbstractHemp (Cannabis sativa L.) synthesizes and accumulates a number of secondary metabolites such as terpenes and cannabinoids. They are mostly deposited as resin into the glandular trichomes occurring on the leaves and, to a major extent, on the flower bracts. In the last few years, hemp for production of high-value chemicals became a major commodity in the U.S. and across the world. The hypothesis was that hemp biomass valorization can be achieved through distillation and procurement of two high-value products: the essential oil (EO) and cannabinoids. Furthermore, the secondary hypothesis was that the distillation process will decarboxylate cannabinoids hence improving cannabinoid composition of extracted hemp biomass. Therefore, this study elucidated the effect of steam distillation on changes in the content and compositional profile of cannabinoids in the extracted biomass. Certified organic CBD-hemp strains (chemovars, varieties) Red Bordeaux, Cherry Wine and Umpqua (flowers and some upper leaves) and a T&H strain that included chopped whole-plant biomass, were subjected to steam distillation, and the EO and cannabinoids profile were analyzed by gas chromatography-mass spectrometry (GC–MS) and HPLC, respectively. The distillation of hemp resulted in apparent decarboxylation and conversion of cannabinoids in the distilled biomass. The study demonstrated a simple method for valorization of CBD-hemp through the production of two high-value chemicals, i.e. EO and cannabinoids with improved profile through the conversion of cannabidiolic acid (CBD-A) into cannabidiol (CBD), cannabichromenic acid (CBC-A) into cannabichromene (CBC), cannabidivarinic acid (CBDV-A) into cannabidivarin (CBDV), cannabigerolic acid (CBG-A) into cannabigerol (CBG), and δ-9-tetrahydrocannabinolic acid (THC-A) into δ-9-tetrahydrocannabinol (THC). In addition, the distilled biomass contained CBN while the non-distilled did not. Distillation improved the cannabinoids profile; e.g. the distilled hemp biomass had 3.4 times higher CBD in variety Red Bordeaux, 5.6 times in Cherry Wine, 9 times in variety Umpqua, and 6 times in T&H compared to the original non-distilled samples, respectively. Most of the cannabinoids remained in the distilled biomass and small amounts of CBD were transferred to the EO. The CBD concentration in the EO was as follows: 5.3% in the EO of Umpqua, 0.15% in the EO of Cherry Wine and Red Bordeaux and 0.06% in the EO of T&H. The main 3 EO constituents were similar but in different ratio; myrcene (23.2%), (E)-caryophyllene (16.7%) and selina-3,7(11)-diene (9.6%) in Cherry Wine; (E)-caryophyllene (~ 20%), myrcene (16.6%), selina-3,7(11)-diene (9.6%), α-humulene (8.0%) in Red Bordeaux; (E)-caryophyllene (18.2%) guaiol (7.0%), 10-epi-γ-eudesmol (6.9%) in Umpqua; and (E)-caryophyllene (30.5%), α-humulene (9.1%), and (E)-α-bisabolene (6.5%) in T&H. In addition, distillation reduced total THC in the distilled biomass. Scanning electron microscopy (SEM) analyses revealed that most of the glandular trichomes in the distilled biomass were not disturbed (remained intact); that suggest a possibility for terpenes evaporation through the epidermal membrane covering the glandular trichomes leaving the cannabinoids in the trichomes. This explained the fact that distillation resulted in terpene extraction while the cannabinoids remained in the distilled material.

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