Capitate Glandular Hairs Research Articles

Developmental Programmed Cell Death Involved in Ontogenesis of Dictamnus dasycarpus Capitate Glandular Hairs.

Plant glandular trichomes have received much attention due to their commercial and biological value. Recent studies have focused on the development of various glands in plants, suggesting that programmed cell death (PCD) may play an important role during the development of plant secretory structures. However, the development processes and cytological characteristics in different types of plant secretory structures differed significantly. This study aims to provide new data on the developmental PCD of the capitate glandular hairs in Dictamnus dasycarpus. Light, scanning, immunofluorescence labeling, and transmission electron microscopy were used to determine the different developmental processes of the capitate glandular hairs from a cytological perspective. Morphologically, the capitate glandular hair originates from one initial epidermal cell and differentiates into a multicellular trichome characterized by two basal cells, two lines of stalk cells, and a multicellular head. It is also histochemically detected by essential oils. TUNEL-positive reactions identified nuclei with diffused fluorescence or an irregular figure by DAPI, and Evans blue staining showed that the head and stalk cells lost their viability. Ultrastructural evidence revealed the developmental process by two possible modes of PCD. Non-autolytic PCD was characterized by buckling cell walls and degenerated nuclei, mitochondria, plastids, multivesicular body (MVB), and end-expanded endoplasmic reticulum in the condensed cytoplasm, which were mainly observed in the head cells. The MVB was detected in the degraded vacuole, a degraded nucleus with condensed chromatin and diffused membrane, and eventual loss of the vacuole membrane integrity exhibited typical evidence of vacuole-mediated autolytic PCD in the stalk cells. Furthermore, protoplasm degeneration coupled with dark oil droplets and numerous micro-dark osmiophilic substances was observed during late stages. The secretion mode of essential oils is also described in this paper.

Rumohra ponceana (Polypodiales: Dryopteridaceae): a new species from Pampean biogeographic province in Argentina

The fern Rumohra ponceana sp. nov., a narrow endemic of the Austral Pampean district, Pampean biogeographic province in Argentina, is described and illustrated. The species inhabits the Tandilia and Ventania Systems, where it grows in sunny rock crevices. The new species differs from the widespread R. adiantiformis (sensu lato) by the reduced size of all parts of the sporophyte and conspicuous capitate glandular hairs at the margins of petiole and rhizome scales. Also, there are significant differences in the architecture of the laminae, the colour and size of the spores and the ornamentation of the perispore, which is folded in R. ponceana and projects in irregular tubercles throughout its surface.

Macro- and microscopic investigation of leaves and flowers cultivated species genus Primula L. – drumstick primrose

Topicality. Many species of genus Primula L. are valuable medicinal and vitamins plants, but analysis of scientific literature demonstrates a lack of systematic information on morphological and anatomical structure of some species of mentioned genus, especially drumstick primrose, so they still remain objects of investigation as perspective.The aim of these studies was investigation of morphological and anatomical structure above ground organs of drumstick primrose and establishing macro- and microscopic diagnostic features of plants, that are necessary for identification of new plant raw material.Materials and methods. The objects of the study were leaves and flowers of drumstick primrose harvested during the plants flowering. Microscopic analysis was performed using commonly accepted methodologies, microscopes MBS9, MS 10, microphotographs made by the Samsung camera PL50.Results and discussion. As a result of conducted investigation, it was found: 1. The morphological diagnostic features: leaves without leafstalk, reaches 20-40 cm in length, collected in a dense rosette. Leaf plate wide thick, elongated, on the edge finely serrated, light green, pubescence, wrinkled and lumpy. Thick peduncles, covered at the top by yellowish cilia. Small flowers on short pedicel, gathered in dense spherical umbrella diameter of 4-10 cm; corolla violet, blue, purple, red, pink or white. 2. Anatomical features: Leaf – leaf plate dorsoventral, hipostomatic; upper epidermis without stomata; lower epidermis of anomocytic type; many specialized cells with orange secret; on the edge of the plate located the teeth of secreting epidermis; lower epidermis densely covered with hairs of two kinds. Peduncles – cylindrical; anatomical structure transition. Primary bark a multilayer, many secretory cells and milkmen with brown contents; ring of conductive bundles narrow; core parenchyma contains many dark secretory structures. Epidermis covered by capitate glandular hairs. Flower – calyx; stomata and hairs absent; contain frequent dark secretory idioblast, veins with segmented milkmen with a yellowish secret. Corolla with secretory cells.Conclusions. For the first time, has been conducted investigation of morphological and anatomical structure features of leaves and flowers cultivated species genus Primula L. – drumstick primrose, detected their typical macro- and microscopic diagnostic features, that make it possible to identify the flowers and leaves of this species primrose and that used to develop the project of quality control methods for the new medicinal plant raw material.

Leaf anatomy of Mallotus and the related genera Blumeodendron and Hancea (Euphorbiaceae sensu stricto)

The leaf anatomy of Mallotus and Hancea (both subtribe Rottlerinae, tribe Acalypheae) and Blumeodendron (tribe Pycnocomeae) from Euphorbiaceae sensu stricto (subfamily Acalyphoideae) was studied in detail on the basis of 84 specimens belonging to 71 species. Some leaf anatomical features do not show much variation; almost all species have a relatively constant dorsiventral mesophyll, paracytic stomata and collateral bundles in the mesophyll. However, the diversity of other characters is great, especially the hair types, and useful in characterizing infrageneric groups. Capitate glandular hairs are characteristic for Hancea, whereas globular to disc-shaped glandular hairs occur in most Mallotus spp. Glandular hairs are absent in the two other genera. Morphological diversity in globular to disc-shaped hairs in Mallotus also provides taxonomically important information. Hancea is characterized by the presence of brachysclereids and cristarque cells and by an abundance of columnar and fibriform mesophyll sclereids. Blumeodendron shares with Hancea the presence of brachysclereids and fibriform sclereids, but is further characterized by the presence of giant stomata. In this study, leaf anatomy is used to discuss the infrageneric delimitation of Mallotus and Hancea and to compare these genera with the more distantly related Blumeodendron. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, ••, ••–••.

Morphology and histochemistry of the glandular trichomes of Isodon rubescens (Hemsley) H. Hara [Lamiaceae]: A promising medicinal plant of China

Isodon rubescens, a perennial herb indigenous to China, with medicinal application, potentially has economic value. The morphology of the glandular trichomes was investigated with light microscopy. At the same time the chemical content was analyzed by applying chemical reagents and fluorescence microscopy. This morphoanatomical and histochemical study revealed that leaves of I. rubescens possess one type of non-glandular and two types of glandular trichomes, with the latter differing both anatomically and in the composition of their secondary metabolites. Non-glandular trichomes were uniseriate with an ornamented surface. Peltate and capitate glandular trichomes comprised one basal cell, one stalk cell and one head. The head of mature peltate glandular trichomes consisted of four-twelve secretory cells while that of the capitate glandular hairs was comprised of two cells. Peltate glandular trichomes containing compounds of terpenoid nature are probably the main site of oridonin and ponicidin accumulation. The fluorescent stain of peltate and capitate glandular trichomes indicated the possible presence of phenolic compounds. Key words: Isodon rubescens, Lamiaceae, glandular trichomes, microscopy, histochemistry, terpenoids, phenolic.

Ontogenesis of trichome-like cavities in Dictamnus dasycarpus

The ontogeny of a special type of glandular hairs, namely the trichome-like cavities in Dictamnus dasycarpus, characterized by many morphological similarities to non-glandular hairs, capitate glandular hairs, and secretory cavities, was studied using light and electron microscopy. These trichome-like cavities originate from a single, initial epidermal cell that undergoes a periclinal division, with one cell developing into the internal cells and the other into the outer, epidermal cells. A beak-shaped apex is formed on the head of the trichome-like cavity. The histochemical test shows that the trichome-like cavities are important sites for lipid production. By ultrastructural analysis it becomes evident that formation of these trichome-like cavities starts with a disorganization of the cytoplasm that is accompanied by formation of odd shaped nuclei with condensed chromatin. The process continues bringing about plasmolytic processes, and disintegration of the plasma membrane system follows leading finally to autolysis, when mitochondria and degenerated plastids with disorganized membrane systems are engulfed by vacuoles, multivesicular bodies, and double-membranous autophagosomes within the vacuoles. A strong structural twist and swelling of the internal cell walls ultimately leads to complete breakdown of the structures. Nuclei of the inner internal cells within the trichome-like cavity become TUNEL-positive and DAPI-negative first; later this is detected also in the outer internal cells, indicating a centrifugal nuclear degradation process. On the basis of this work, it can be assumed that the lysigenous formation of the trichome-like cavity is a typical programmed cell death process.

Morphological and anatomical studies on two varieties of Phlomis pungens Wild. (Lamiaceae)

In this study, morphological and anatomical features of two varieties of Phlomis pungens Wild. (P. pungens Wild. var. pungens and P. pungens Wild. var. hispidaHub.-Mor.) were investigated and compared. In addition, glandular and eglandular hairs were examined and classified. We observed that hair types of the two varieties were different. Both varieties of P. pungens had Type I capitate glandular hairs while Type III capitate hairs which had a cup-like head cell were only present on P. pungensvar. hispida. Key words: Phlomis pungens, anatomy, morphology.

Multivariate Numerical Taxonomy of Mentha Species, Hybrids, Varieties and Cultivars

A taxonomic study into the anatomical, morphological and phytochemical differentiation of the genus Mentha L (Lamiaceae) in Bosnia & Hercegovina and Slovakia is presented. Following a population-based approach and using hierarchical cluster analyses the following basic species and hybrids corresponding to exclusive branches, i.e. groups, in the constructed hierarchies were recognized: Mentha aquatica, M. spicata, M. arvensis, M. longifolia, M. rotundifolia, M. × piperita, M. × villosa, M. × verticillata, M. × gentillis, M. × gracilis and M. pulegium. These groups were independently found by separate analyses of the sampled anatomical and morphological variation. In contrast, these anatomically and morphologically defined species exhibited a high level of phytochemical polymorphism which was largely inconsistent with the hierarchical classification. Among the analysed characters, the inflorescence type, dentation of the leaf margin, hair density, the type of capitate glandular hairs, and the main containing compound in essential oil proved most useful for the discrimination of taxa. However, most of the observed traits were not exclusive to a particular species and only the combined consideration of traits revealed coherent taxonomic groups. Basic species and hybrids are described in detail based on the anatomical, morphological and phytochemical characters used for their definition. The performed cluster analysis finally supported hypotheses on the parentage of some of the studied hybrids.

Re-shaping Mallotus [Part 1]: Expanded circumscription and revision of the genus Cordemoya (Euphorbiaceae)

A recent phylogenetic study based on DNA sequence data detected a well-supported clade of a number of Mallotus species together with the genus Cordemoya. This clade is distinct from the large Mallotus s.s. clade. In this paper, Cordemoya (formerly monotypic with C. integrifolia from the Mascarene Islands) is expanded with sixteen additional species previously assigned to Mallotus. Taxa transferred to Cordemoya are: Mallotus sections Hancea and Oliganthae from Asia and M. baillonianus, M. capuronii, and M. spinulosus from Madagascar. The genus Cordemoya can be distinguished from Mallotus s.s. by the presence of pollen with areolate ornamentation with scabrae (perforate/microreticulate ornamentation with scabrae in the sample of Mallotus s.s. studied up to now) and of capitate glandular hairs with multicellular stalks and sessile peltate-stellate hairs with a central cell (spherical to disc-shaped multicellular glandular hairs in Mallotus). In the new circumscription of Cordemoya two subgenera are recognized: Cordemoya from Madagascar and Mascarenes and Diplochlamys from Asia. The latter is divided into two sections: Diplochlamys (former sect. Hancea), and Oliganthae. A taxonomic revision of part of these taxa is provided (excl. section Diplochlamys); descriptions, distribution maps, habit drawings and a key are included.

Primula farinosa L.

Perennial rosette hemicryptophyte. Rosettes with a short, up to 5 mm, erect conical/discoid axis, bearing a succession of closely spaced leaves, and giving rise to intercalary primordia which may alternatively differentiate into adventitous roots, inflorescences, vegetative buds, or sessile, tangentially flattened, winter bulbils. Leaves, sometimes fleshy, incurled, 1-5(-10) cm long, 0.3-2 cm broad, oblanceolate, oblong-ovate to elliptic, obtuse or subacute, sometimes narrowing into a petiole-like basal region which may represent almost half of the length, finely toothed or crenulate to entire, green, somewhat glistening above when mature with, in the type subspecies, whiteor sulphur-coloured farina on abaxial surface; farina on both surfaces of unexpanded leaves, and of apetiolate leaves in overwintered newly expanding rosettes; farina sometimes initially present on adaxial surface of expanded leaves but subject to removal by weathering. Cotyledons and leaves with scattered unicellular capitate glandular hairs on upper surfaces; similar hairs also on hypocotyl. Scape(s) (mostly absent in one British population) originating among leaf bases of rosettes, thick striate 0-3 cm tall, or thinner 2-20(-30) cm tall reflecting an intrapopulation genetic polymorphism (a varietal name, acaulis Ahlq., has been applied). Scape sparsely glandular, farinose entirely when young, distally only later, bearing one umbel (or unusually two umbels 'candelabra-like' on the same axis) with few or many (< 30) flowers or flower buds not all of which may mature, flexible during flowering, rigid during fruiting. Pedicels c. 5 mm, slender, slightly spreading, becoming twice as long as bracts, farinose. Bracts 2-8 cm long, narrow lanceolate, to subulate, acute or acuminate, broadened at the markedly gibbous base, more or less farinose. Calyx cylindric or urceolate becoming cuplike in fruit, 3-6 x 2 mm, farinose both within and without; usually five-angled and toothed, with the teeth obtuse, or more rarely acute, often tinged with purple or black. Corolla annulate, with 5-partite limb 8-16 mm across with flat segments mutually distant, but not so in all populations, cuneate, or cordate (with spaces between petals obscured), bifid, coloured lilac, deepest crimson, shades of purple, rarely bluish or white, deep yellow in the throat, and with tube 5-8 mm long, greenish-yellow equalling or slightly exceeding the calyx. Heterostylous; stamens epipetalous set either in the upper part of the tube (thrum-eyed flowers), or in the middle of the tube (pin-eyed flowers), these on separate clones; the former flowers with style half as long as the calyx the latter with the style reaching almost to the annulus. Capsule cylindrical, obtuse, usually much exceeding the calyx, 5-9 mm long, green, farinose becoming shiny brown, opening apically through splitting into five (unusually more) triangular, obtuse 1-mm long segments. Seeds c. 0.5 mm diameter; mean seed weights for populations ranging from 48.4 .Lg to 76.3 [Lg (Tremayne & Richards 2000), borne on axile placenta, may appear coffin-shaped in transverse aspect, ovoid to quadrate angular when released, golden brown when mature, minutely vesicular-surfaced vesicles are single cells, smaller than those of its near relative the Scottish endemic P scotica Hook. Root

Histological Structure of the Anthers and Microsporogenesis inSalvia tomentosaMill. (Labiatae)

ABSTRACT A cytoembryological study of Salvia tomentosa indicates anther walls are 4 layers built of an epidermis, endothecium, middle layer, and secretory tapetum. Peltate and capitate glandular hairs formed on the anther epidermis. Degeneration processes were observed during the microspore- and microgametogenesis, starting at diakinesis.

The Filament Bundle ofMentha piperita

Bundles consisting of 6 to 8 parallel filaments (6 nm thick) are localized in both the cytoplasm and the nucleus - particularly in mesophyll cells and in 3-celled capitate glandular hairs, but not in the 10-celled glandular peltate hairs of the leaves of MENTHA PIPERITA. They are present in as yet 8 investigated species of the genus MENTHA, but not in 8 further genera of the Lamiaceae. The bundles are therefore genus-specific; they consist of protein only. A possible connection with the production of essential oil is discussed.

Sunflower allergy. On the constituents of the trichomes of Helianthus annuus L. (Compositae).

Sesquiterpene lactones (STL) of the sunflower, occurring in fragile multicellular capitate glandular hairs, have been shown to display a remarkable sensitizing capacity when investigated by experimental sensitization in guinea pigs. The strongest response was induced by the hemiketal form of 1-O-methyl-4,5-dihydroniveusin A. The STL content of 50 capitate glands was sufficient to elicit a remarkable response in the guinea pigs. Thus, touching a sunflower plant (with up to 1000 capitate glands per cm2) may lead to the release of sufficient STL to sensitize humans, and these substances can be considered to be responsible for the cases of allergic contact dermatitis described in sunflower growers since 1906.

Capitate Glandular Hairs from Sunflower Leaves: Development, Distribution and Sesquiterpene Lactone Content

Sesquiterpene lactones of the sunflower, Helianthus annuus L., are synthesized and stored in capitate glandular hairs of the epidermis. The amount of two major compounds (niveusin C and 15-hydroxy-3-dehydrodesoxyfruticin) per leaf increases during leaf development, whilst the quantity per cm2 leaf area decreases. This is the result of two contrary processes: increasing synthesis in the glandular hairs and the «dilution» of the trichomes per cm2 leaf area, caused by leaf growth. The formation of capitate glands precedes the development of the other leaf cells and their number seems to be determined at an early stage. The increasing amount of sesquiterpene lactones from basal to apical leaves is due to the number of trichomes per leaf and not different rates of synthesis in the glands. However, the formation of the compounds in the trichomes is influenced by climatic factors. Intense light leads to a high rate of secretion. The phytochrome system is involved in the synthesis of sesquiterpene lactones, whilst the rate of photosynthesis has no primary effect on this metabolism.

Sesquiterpene Lactones in Glandular Trichomes of Sunflower Leaves

Summary Microscopical investigations of the leaf surface of sunflower seedlings (Helianthus annuus L.) revealed the presence of three types of glandular and nonglandular trichomes. A chemical analysis of the mechanically collected hairs established the existence of six sesquiterpene lactones in the resinous content of multicellular capitate glandular hairs. Among the extracted compounds the known sesquiterpene lactones niveusin C, argophyllin B, and 15-hydroxy-3-dehydrodes-oxyfruticin could be identified by means of MS-, 1H-, and 13C-NMR spectroscopic measurements. The amount of niveusin C and 15-hydroxy-3-dehydrodesoxyfruticin in the cuticular globe of a single mature gland was determined by HPLC analysis to be about 6 ng and 43 ng.

Density and Distribution of Erect Glandular Hairs on Annual Medicago Species

Erect glandular hairs on several annual Medicago species are associated with mechanisms that defend the plants against certain destructive insects. To aid in elucidating the resistance mechanism, we investigated the density and distribution of erect glandular hairs on four annual Medicago species: two tetraploids (2n = 4x = 32), M. scutellata (L.) Mill. and M. rugosa Desr., and two diploids (2n = 2x = 16), M. disciformis DC. and M. blancheana Boiss. Erect capitate glandular hairs were present on all vegetative and floral parts of the four species except cotyledons and flower petals. Density was not affected by ploidy level but showed differences, depending on whether the plants had been grown in the field or greenhouse. Both diploids and tetraploids had glandular hairs on margins of leaflets. The glandular hairs were distributed over the entire abaxial leaf surface of tetraploids, and on diploids they were confined to the midrib area. Hairs were densest on the peduncle, followed by the stem, petiole, seed...

MORPHOGENESIS OF CAPITATE GLANDULAR HAIRS OF CANNABIS SATIVA (CANNABACEAE)

The glandular secretory system in Cannabis sativa L. (marihuana) consists of three types of capitate glandular hairs (termed bulbous, capitate‐sessile, and capitate‐stalked) distinguishable by their morphology, development, and physiology. These gland types occur together in greatest abundance and developmental complexity on the abaxial surface of bracts which ensheath the developing ovary. Bulbous and capitate‐sessile glands are initiated on very young bract primordia and attain maturity during early stages of bract growth. Capitate‐stalked glands are initiated later in bract growth and undergo development and maturation on medium, to full sized bracts. Glands are epidermal in origin and derived, with one exception, from a single epidermal initial. The capitate‐stalked gland is the exception and is of special interest because it possesses a multicellular stalk secondarily derived from surrounding epidermal and subepidermal cells. Glands differentiate early in development into an upper secretory portion and a subtending auxiliary portion. The secretory portion, depending on gland type, may range from a few cells to a large, flattened multicellular disc of secretory cells. The secretory portion produces a membrane‐bound resinous product which caps the secretory cells. Capitate‐stalked glands are considered to be of particular evolutionary significance because they may represent a gland type secondarily derived from existing capitate‐sessile glands.