Characteristics of the submicroscopic structure of the leaf epidermis in Hypodematium (Hypodematiaceae) from China and its taxonomic significance

In order to obtain qualitative and quantitative characteristics of leaf epidermal micromorphology and mesophyll structure to evaluate the responses of Elaeagnus angustifolia L.to different environmental factors,epidermal micromorphology was observed by scanning electron microscopy(SEM),and mesophyll structure was studied by light microscopy(LM) and transmission electron microscopy(TEM).Materials were selected from Linze County,Gansu Province(material A) and Qitai County,Xinjiang Uygur Autonomous Region(material B) of China.Results show that lamina thickness was higher in material A,with one layer of epidermal cells in both adaxial and abaxial surfaces,and epidermal cell radial length was significantly longer in the adaxial surface.E.angustifolia leaves are typically bifacial,with a higher ratio of palisade to spongy tissue in material A.The thickness of trichome layer of epidermis was thicker in material A.In contrast,cell wall and cuticular wax of the epidermal cells were thinner in material A than in material B.Chloroplast ultrastructure was different with the approximate spherical chloroplast containing numerous starch grains and osmiophilic granules in material A,while only the spindly chloroplast contained starch grains in material B.Multiple layers of peltate or stellate-peltate trichomes occupied both leaf surfaces in material A and the abaxial surface in material B,while the adaxial surface of material B contained few trichomes.Stomata were not observed on the leaf surfaces in materials A and B by SEM because of trichome obstruction.Our results indicate that the leaf structure of E.angustifolia is closely correlated with environmental factors,and the combination of leaf epidermal micromorphology and mesophyll structure afford resistance to environmental stress.

The foliar micromorphology of Arctotis arctotoides (L.f.) O. Hoffm. a medicinal plant in the Eastern Cape Province, South Africa was investigated using the Scanning Electron Microscope (SEM). The leaf surfaces of the plant were characterized by anisocytic stomata, glandular and non-glandular trichomes. The abaxial surfaces had more stomata and glandular trichomes than the adaxial surfaces of the leaf. Crystal deposits were also observed around the stomata and near the glandular trichomes. Energy dispersive X-ray spectroscopy showed that Na, Mg and Ca were the major constituents of the crystals. Naturally, distinct morphological variations existed among the ultra structures on the leaf surfaces of the plant. The distributions of the stomata and the two types of trichomes on both surfaces also differed both in shape and in structure. The presence of glandular trichomes on the leaf surfaces of this herb may serve as secretory sites where secondary metabolites are produced. Key words: Arctotis arctotoides, foliar micromorphology, stomata, trichomes, crystals.

Plant trichomes constitute a first line of defence against insect herbivores. The pre- and post-ingestive defensive functions of glandular trichomes are well documented and include direct toxicity, adhesion, antinutrition and defence gene induction. By contrast, the defensive functions of non-glandular trichomes are less well characterized, although these structures are thought to serve as physical barriers that impede herbivore feeding and movement. We experimentally varied the density of stellate non-glandular trichomes in several ways to explore their pre- and post-ingestive effects on herbivores. Larvae of Manduca sexta (Sphingidae) initiated feeding faster and gained more weight on Solanum carolinense (Solanaceae) leaves having lower trichome densities (or experimentally removed trichomes) than on leaves having higher trichome densities. Adding trichomes to artificial diet also deterred feeding and adversely affected caterpillar growth relative to controls. Scanning electron and light microscopy revealed that the ingestion of stellate trichomes by M. sexta caterpillars caused extensive damage to the peritrophic membrane, a gut lining that is essential to digestion and pathogen isolation. These findings suggest that, in addition to acting as a physical barrier to deter feeding, trichomes can inhibit caterpillar growth and development via post-ingestive effects.

Effects of saflufenacil in Merremia aegyptia (Convolvulaceae), Luffa aegyptiaca (Cucurbitaceae) and Mucuna aterrima (Fabaceae - Leguminosae) were analyzed by scanning electron microscopy one day before and after application. Stomatal density, stomatal index and length of the stomatal aperture were determined by imprinting the leaf epidermis. These species showed stomata on the adaxial and abaxial epidermis. M. aegyptia showed paracytic stomata, unicellular tector trichomes on the abaxial surfaces, especially around leaf veins, and absence of epicuticular wax crystals. L. aegyptiaca was characterized by having anomocytic stomata, glandular trichomes and multicellular trichomes on both sides of the leaf, and did not have epicuticular wax crystals. M. aterrima showed anisocitic stomata, glandular and unicellular trichomes on both sides as well as a large amount of epicuticular wax crystals. The herbicide saflufenacil promoted dispersion of waxes, epidermal surface roughness and depletion of trichomes on L. aegyptiaca and M. aterrima plants. There were significant differences in the stomatal index, density and length of stomatal aperture among the studied species.

Micromorphological characters from fruit surface of 24 species and seed coat of 21 species, 6 subgenera of Rhododendron from China, i.e., Azaleastrum, Hymenanthes, Pentanthera, Rhododendron, Therorhodion and Tsutsusi, were examined under the scanning electron microscope. Ledum palustre was also examined to compare with the species of Rhododendron. The micromorphological characters of fruit surface and seed coat in Rhododendron are described in this paper. Different types are distinguished here on the basis of morphological characters such as scale, trichome, stomatal apparatus of fruit surface, and ornamentation of seed coat. Compared with seeds of extant and fossil Rhododendron species, some new seed types in Rhododendron species from South China are found. R. redowskianum of subgen. Therorhodion has sparse short setas on the fruit surface without stomatal apparatus. Outline of its slightly flattened and unwinged seed is narrowly oblong. Subgen. Rhododendron, the lepidote rhododendron, with scales on fruit surface, as well as brain-line ridge on the seed coat, differs distinctly from the elepidote rhododendron. Fruit surface of the species in subgen. Hymenanthes belongs to R. fortunei-type, which is characterized as the irregular cuticular membrane without trichome, with stomatal apparatus rarely seen. In the species of subgen. Tsutsusi, the type of fruit surface belongs to R. mariae-type, which is characterized as the compact cuticular membrane with thick trichomes. As far as seed coat is concerned, only one type is found in subgen. Hymenanthes (i.e., R. fortunei-type), whereas two types occur in subgen. Tsutsusi (i.e., R. meridionale-type and R. mariae-type). The species of subgen. Azaleastrum show the great divergence on morphological characters. Separately, sect. Choniastrum and sect. Tsutsusi exhibit their own micromorphological characters. According to the morphological characters of fruit surface, R. molle of subgen. Pentanthera differs distinctly from the species of other subgenera. However, its R. molle-type seed is similar to R. fortunei-type seed. The above-mentioned morphological characters support the results frommolecular systematic studies: except for subgen. Therorhodion, the lepidote rhododendron (subgen. Rhododendron) plus Ledum, is monophyletic; subgen. Tsutsusi from China and subgen. Hymenanthes are both monophyletic; subgenera Azaleastrum and Pentanthera are both polyphyletic; and in subgen. Azaleastrum, sect. Choniastrum and Tsutsusi are both monophyletic. Furthermore, the relationships between the closely related taxa are also inferred from micromorphological characters and molecular data. This study provides micromorphological evidence to support the separation of R. bachii from R. ovatum as a distinct species.

Moniliasis of cocoa is an important disease caused by the fungus Moniliophthora roreri (Cif & Park) (Evans et al 1978). A study was conducted on the external features of fruits of two cocoa cultivars with different degrees of susceptibility to M. roreri also a comparative study of the exocarp tissues of healthy fruits was conducted. Scanning Electron Microscopy (SEM) and High Resolution Optical Microscopy (HROM) were used respectively. For SEM, sixty-day-old healthy fruits of cvs Pound-7 (susceptible) and UF-296 (moderately resistant) were collected from CATIE's germplasm collection in Turrialba and La Lola, Costa Rica. Apparently, no external anatomic differences between the fruits of the Pound 7 and the UF-296 (moderately resistant) cultivars exist, except for the star-like trichomes in the latter. Both show an alveolar epidemis on which there are noticeable anomocitic-type stomata and a large number of glandular trichomes. For HROM, healthy Pound-7 and UF-296 fruits from La Lola were used, as well as cv. UF-273 resistant to the pathogen. The major histological feature of cv UF-273 and UF-296 was a cellular arrangement of the subepidermic parenchyma which was more compact, probably containing larger amounts of phenolic substances in the vacuoles, as compared to the Pound 7.

Abstract. Bersamin AT, Tayaben JL, Balangcod KD, Balangcod AKD, Cendana AC, Dom-Ogen ET, Licnachan LOC, Siadto B, Wong FM, Balangcod TD. 2021. Utilization of plant resources among the Kankanaeys in Kibungan, Benguet Province, Philippines. Asian J Ethnobiol 4: 362-372. The use of plant resources for human basic need dates back to ancient times. Plants have been man’s recourse for natural healing, food, and for cultural practices. This study aimed to document the rich flora of Kibungan, Benguet that the Kankanaey tribe utilizes. Interviews and focused group discussions were used to gather data and it was supplemented with ocular inspection of the locality. Results revealed that there were various uses of plants that could be categorized into medicinal, food, house construction, and others. The leaves of medicinal plants are more frequently used to treat wounds, diarrhea, cough, and skin inflammation. Decoctions for natural remedies include gipas (Sarcandra glabra), gawed (Piper betle), and kutsay (Allium odorum). Plant foods such as fruits, root crops, and vegetables are either cultivated or gathered from the forest. Specifically, plants collected from the wild included pinit (Rubus fraxinifolius), amti (Solanum nigrum), bayabas (Psidium guajava), gatgattang (Sonchus arvensis), galyang (Alocasia macrorrhizos), and pako (Diplazium esculentum), while kamote (Ipomea batatas) and corn (Zea mays) are cultivated. The pine tree (Pinus kesiya) is the main raw material for house construction. Interestingly, dengaw (Acorus calamus) is regarded as an amulet, which is believed to ward off evil spirits.

The leaf epidermis of Japanese honeysuckle (Lonicera japonica Thunb.) and Wild Honeysuckle (Lonicera confusa) in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes (SEM) to study the characteristics of stomata, trichomes and dermal cell, etc.. The results showed that stoma exists only on the lower epidermis and its distribution is irregular, and leaf epidermis consist of epidermis cells, stoma complexes and bushy trichomes including glandular hair and non-glandular hair. On the upper epidermis, anticlinal wall caves in sinuous groove to countercheck the transpiration. Evidences from leaf morphological structures serve as another proof on drought-resistant mechanisms. Some strumaes distributing regularly are hypothesized as oxalic calcium on the lower epidermis under laser scanning confocal microscopy (LSCM) with Fluo-3/AM, which can increase their endurance to drought stress. Therefore, the above characteristics of Flos Lonicerae can reduce the loss of water and make Japanese honeysuckle and Wild Honeysuckle adapt to the droughty environment at Karst area in southwest China. However, there is some difference of the two species. From the SEM (Scanning Electron Microscopy) result, it is shown that on the upper epidermis, some glandular hair regularly present along the midrib of Japanese honeysuckle, but Wild Honeysuckle has no glandular hair on the upper epidermis, which can verify the relationships of Flos Lonicerae species and provide the significance for classification of Flos Lonicerae.

Non-glandular and three types of glandular trichomes localized on a peduncle and the phyllaries of two species (Doronicum orientale and D. macrophyllum) belonging to Senecioneae tribe of Asteraceae were studied by light and electron microscopy, as well as on histochemistry. The plant species differ on the trichome morphology, anatomy and arrangement. Three types of the glandular trichomes are formed on the vegetative and reproductive organs in D. orientale, whereas only one type exists in D. macrophyllum. It was shown by fluorescent microscopy and histochemistry that the phenolic substances, terpenoids and sesquiterpene lactones present in the glandular trichomes. The received results allow assuming that secretion of the trichomes is a chemical barrier to insects and fungi.

In the present study, we aim to explore whether the caspase-3-dependent pathway is involved in the apoptotic cell death that occurs in the hair cells (HCs) of guinea pig cochlea following a salicylate treatment. Guinea pigs received sodium salicylate (Na-SA), at a dose of 200 mg·kg(-1)·d(-1) i.p., as a vehicle for 5 consecutive days. In some experiments, N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone (zDEVD-FMK), a specific apoptosis inhibitor, was directly applied into the cochlea via the round window niche (RWN) prior to salicylate treatment for determination of caspase-3 activation. Alterations in auditory function were evaluated with auditory brainstem responses (ABR) thresholds. Caspase-3 activity was determined by measuring the proteolytic cleavage product of caspase-3 (N-terminated peptide substrate). DNA fragmentation within the nuclei was examined with a terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method. Ultrastructure variation in the target cell was assessed by electron microscopy (EM). Salicylate treatment initiated an obvious elevation in ABR thresholds with a maximum average shift of 60 dB sound pressure level (SPL), and caused significant apoptosis in both inner (IHCs) and outer (OHCs) hair cells resulted from an evident increasing in immunoreactivity to caspase-3 protease. Transmission electron microscopy (TEM) displayed chromatin condensation and nucleus margination accompanied by cell body shrinkage in the OHCs, but not in the IHCs. Scanning electron microscopy (SEM) showed breakdown, fusion, and loss in the stereociliary bundles at the apex of OHCs rather than IHCs. zDEVD-FMK pretreatment prior to salicylate injection substantially attenuated an expression of the apoptotic protease and protected HCs against apoptotic death, followed by a moderate relief in the thresholds of ABR, an alleviation in the submicroscopic structure was also identified. In particular, disorientation and insertion in the hair bundles at the apex of OHCs was exhibited though no classic apoptotic change found. The above changes were either prevented or significantly attenuated by zDEVD-FMK. These findings indicate that salicylate could damage cochlear hair cells via inducing apoptosis associated with caspase-3 activation.

In this study, Minuartia imbricata (M.Bieb.) Woronow, M. aizoides (Boiss.) Bornm., M. circassica (Albow) Woronow of the genus Minuartia L. belonging to the family Caryophyllaceae have been investigated according to their trichome features micromorphology. The trichomes of leaf margins, leaf surfaces, pedicels, and sepals of the three closely related species have been compared and illustrated by using Scanning Electron Microscopy (SEM) and Light Microscopy (LM). M. imbricata and M. aizoides were observed leaf margins as long pubescent of their leaf margins. However, M. circassica was rare puberulous. Although M. aizoides and M. circassica have glandular hairs on pedicel, M. imbricata have not got glandular hairs on pedicel. Also, the taxa have different hair lengths.

The diversity of non‐glandular and glandular hairs of Cannabis sativa L. (marihuana) are described by scanning electron microscopy. The non‐glandular hairs are of two major types, as distinguished by size differences and locations, and all of them are highly silicified. The presence of silica as well as cystoliths of calcium carbonate help in the identification of marihuana even in its ash residues. X‐ray microanalyses of Cannabis hairs are compared with those of Humulus lupulus and Lantana camera, whose hairs have been considered to resemble those of marihuana. Glandular hairs are found to be of two major categories. One group consists of glands whose heads are generally made up of eight cells and the other group whose heads are generally made up of two cells but never more than four cells. All glands of both categories are stalked. Some glands of the first category are massively stalked and these are restricted solely to anthers and bracts of staminate and pistillate plants. The massive stalk is considered to be made up of epidermal and hypodermal cells that have grown in response to some stimulation during anthesis. Fine details of the shoot system of Cannabis, such as cuticular ridges on epidermal cells, warty protuberances on non‐glandular hairs, and surface views of glands in developing stages are also reported. Glandular hairs on the bracts of Humulus lupulus resemble those of Cannabis.

<p>Due to the presence of secondary metabolites exhibiting pharmacological activity, the flowers of <em>Rosa rugosa</em> Thunb. have found application in traditional and folk medicine. The essential oil obtained from them is also considered to be a phytoncide. The morphological and anatomical characters of glandular trichomes located on the sepals of <em>R. rugosa </em>were studied by light and scanning electron microscopy. Using histochemical tests, the type of secretion produced in the trichomes was determined and its contents were compared with the secretion produced by the papillae on the petals.</p><p>It was found that multicellular glandular trichomes, having the features of colleters, and non-glandular trichomes were located on the abaxial epidermis, while only non-glandular trichomes were situated on the adaxial epidermis. The stalk cells of the glandular trichomes are arranged in multiple rows, whereas the epidermal cells of the head are arranged radially. The capitate trichomes were classified into two types: short and long trichomes. The largest density of glandular trichomes was recorded in the basal abaxial epidermis and in the middle part of the sepals. During the initial stages of bud development, the glandular hairs were green colored, whereas in the next development stages they changed the color to red. The histochemical tests used allowed us to find that the trichomes on the sepals and the papille on the petals produced lipid substances, polyphenols, tannins, and flavonoids. Sesquiterpenes were found only in the secretion of the glandular hairs on the sepals.</p>

The microstructure of the organs surface of the water fern Salvinia natans (L.) All. has been studied under scanning electron microscope. It was established that the existence on the border between air and water environments is suported by specific microstructure of floating leaves. The adaxial side of floating leaves has well-developed cuticle and stomata placed below the level of epidermis, while abaxial surface of such leaves and submerged modified leaves are characterized by ultra-thin cell walls of the epidermis and numerous filamentous trichomes. We calculated number of stomata per unit area of leaves and the average diameter of stomata. It is claimed that the structure of wall of the sporocarp promotes the passage of the annual summer-green rhythm. Sporocarp provides diving of mega- and microsporangia to the bottom of the water reservoir in autumn and their raising on the water surface in the spring after destruction of its walls.

1. The selection of transmission or scanning electron microscopes depends on the goal of the investigation and the object investigated. 2. The use of the transmission electron microscope is expedient in studying the characteristics of the fine structure which are revealed at large magnifications and require a high resolving capacity. 3. It is expedient to use the scanning electron microscope to study the characteristics of the structure which can be revealed by the three-dimensional picture in a large range of magnifications. 4. It is possible to determine the character of fracture from the fine structure (ductile, brittle, intergranular, and fatigue fractures) with scanning and transmission electron microscopes, since the microfractographic patterns obtained with both instruments are identical. 5. It is of considerable interest to analyze the characteri of fracture with the scanning electron microscope with use of stereoscopic images, which permit the most complete analysis of the structure. The method of preparing and analyzing stereoscopic images is of great practical interest, since it opens up additional possibilities for quantitative analysis of fractures.