Stomatal Ontogeny Research Articles

Epidermal Structures and Stomatal Ontogeny in Terminalia catappa L. (Combretaceae)

Stomatal ontogeny and epidermal characteristics of Terminalia catappa L., an important tropical economic plant, were studied and described. The central portions of cotyledonary and mature leaves were peeled, stained with acetocarmin, 1% safranin and fast green stains as required, mounted on microscope slides and observed under Olympus photomicroscope for stomata ontogeny and developmental stages. The cells of the epidermis of the species are polygonal, isodiametric or elongated in various directions and arranged irregularly. The anticlinal epidermal walls are sinuous, undulating, straight or arched. Combretaceous eglandular trichomes were observed on the abaxial surface of the cotelydonary leaves. Six types of stomata (anomocytic, tetracytic, stuarocytic, anisocytic, isotricytic, diacytic) and different transitional stages were also observed. Stomata occurrence in cotyledonary leaves was observed to be amphistomatic but hypostomatic in mature leaves. The adaxial stomatal index on the cotyledonary leaves ranged from 3.57-14.29 (9.61±3.15) while on the abaxial surface it varied from 12.50-31.25 (23.50±5.13). The ontogeny of isotricytic stomata is mesogenous; it is however mesoperigenous in anomocytic, tetracytic and anisocytic stomata types. Stomata clusters are frequent on the abaxial surface of mature leaves while contiguous stomata and abnormal stomata with unequal guard cells are rare. Stomatal ontogeny, an important taxonomic character, is described for the species.

The pattern of cuticular blue-fluorescing phenolics deposition during the development of Prunus persica leaves

Although stomatal ontogeny is closely related to the development and maturation of the epidermal tissue, stomatal patterns in relation to cuticle construction and cuticular material deposition during leaf development have not received adequate attention. We observed the deposition of blue-fluorescing cuticular phenolics over guard and epidermal cells, as well as stomatal formation and patterning using the alkali-induced blue fluorescence of the cuticle of Prunus persica leaves. Stomata of different stages of maturity occurred together during leaf development, mainly at the tip of the lamina. The deposition of fluorescing compounds initially appeared over the guard cells of the developing stomata complexes and gradually extended to the neighbouring epidermal cells. Based on the blue fluorescence emitted by the cuticular layers, we constructed digital maps of leaves of different developmental stages, showing the pattern of stomatal formation and deposition of fluorescing compounds. A longitudinal tip-to-base gradient in the formation of stomata, as well as in the deposition of fluorescing compounds was observed in young developing leaves. The deposition of blue-fluorescing phenolic compounds seems to be coordinated with stomatal development.

The Stomatal Ontogeny and Structure of the Liassic Pteridosperm Sagenopteris (Caytoniales) from Hungary.

Stomatal ontogeny is often inferred but rarely documented for extinct fossil plants because it requires observations from young leaves that are rarely preserved as fossils. The discovery of several very young leaves of the Jurassic plant Sagenopteris (Caytoniales) in the Mecsek Mountains (southern Hungary) in a good state of preservation provides the opportunity for studying the stomatal ontogenesis of this genus. The specimens show perigenous anomocytic stomata. This feature confirms the evolutionarily high position of Sagenopteris among fossil gymnosperms and supports the opinion that the ancestors of angiosperms and some groups of pteridosperms might be closely related. Such clear examples of stomatal development have not previously been documented for fossil material.

Stomatal ontogeny and morphology in Phaseolus vulgaris in relation to infection structure initiation by Uromyces appendiculatus

The development and morphology of the stomatal complex in Phaseolus vulgaris was examined by light microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The outer aperture formed between the stomatal guard cells was bordered by cuticular ledges, 1.2–5.3 μm wide. These were composed of a matrix of electron-dense fibrils supporting an autofluorescent amorphous outer layer, homologous to the cuticle. This layer of cuticle lined the ventral walls of the guard cells and extended into the substomatal chamber. During stomatal development, as the guard cells separated, the outer cuticular layer covering the incipient aperture stretched and split, forming stomatal lips. These lips, 0.2–1.4 μm wide, were oriented horizontally, upright, and folded back from the ledge in TEM thin sections. In cryopreserved stomata, the lips were generally oriented upright regardless of whether the outer aperture was open or closed. Previous studies have implicated that stomatal lips may function to signal appressorium formation in urediniospore germlings of Uromyces appendiculatus. This study indicated that dimensions of the lips were within the parameters required to induce appressorium formation on artificial membranes. Other components of the stomatal architecture may also be involved in the induction of appressorium formation. Key words: Uromyces appendiculatus, Phaseolus vulgaris, stomata, cuticle, appressoria.

Observations on the cuticular features and stomatal ontogeny in the leaves of some Papilionaceae from Nigeria

AbstractEpidermal morphology and ontogeny of stomata in the leaves of 21 species of family Papilionaceae have been reported. Stomata are confined on both surfaces in the species of Crotalaria Indigofera and Mucuna and only on a lower surface in the rest of the species. Inspite of stomatal diversity even on the same surface, the most prevalent type observed is paracytic with eumesogenous and hemimesogenous ontogeny. Anisocytic stomata with hemimesogenous ontogeny is typical of Crotalaria and anomocytic with agenous ontogeny is typical of Indigofera.

Phylogenetic and systematic value of stomata in Bicarpellatae (BENTHAM et HOOKER sensu stricto)

AbstractFoliar epidermal morphology and ontogeny of stomata are described for 320 taxa distributed in 13 families of the Bicarpellatae. The epidermal cells are generally straight‐walled in the woody taxa but sinuous in herbs and small shrubs. The different stomata types commonly described in the dicotyledons viz: anomocytic, anisocytic, paracytic and diacytic have been recognized during the present study. The families Acanthaceae and Labiatae are remarkable in showing only diacytic stomata generally regarded as the most advanced. The distribution, size and frequency of stomata could be used to establish systematic divisions and to suggest phylogenetic relationships within the Bicarpellatae. Ontogeny of stomata is uniform only in the family Oleaceae but heterogenous in all the other families. Evidence from stomatal ontogeny therefore appears to be taxonomically important only at the genus level. Single guard‐celled stomata, aborted stomata and contiguous stomata are of regular occurrence in the presently investigated families except the family Scrophulariaceae which showed no stomatal abnormalities. Adjacent stomata with cytoplasmic connections between their guard cells are of rare occurrence and such stomata are recorded in only six taxa distributed in the families Gentianaceae, Oleaceae and Solanaceae.

Observations on the cuticular features and stomatal ontogeny in the leaves of some Papilionaceae from Nigeria

Observations on the cuticular features and stomatal ontogeny in the leaves of some Papilionaceae from Nigeria

Structure and ontogeny of stomata in some tropical ornamental plants (Monocotyledons)

Abstract Stomatal features and ontogeny of stomata of 11 ornamental taxa of monocotyledonous families with Agavaceae (1 species), Amaryllidaceae (1 species), Araceae (3 species), Cannaceae (1 species), Commelinaceae (3 species), Liliaceae (1 species), and Musaceae (1 species) have been studied. Features like stomatal area, leaf area occupied by stomata and per cent leaf area occupied by stomata are reported for these taxa for the first time.

Foliar epidermis and taxonomy in Apocynaceae

Mature epidermis and stomatal ontogeny were studied in the leaves of 10 species (9 genera) belonging to Apocynaceae. Abaxial intercostal cells ofWrightia tinctoria are straight-walled and those of adaxial side inWrightia tinctoria, Cascabela thevetia andCarissa spinarum are sinuous. Adaxial epidermis ofRauvolfia tetraphylla is papillose. Hairs are thin-walled inPlumeria rubra (unicellular) andCarissa spinarum (uniseriate) and thick-walled inRauvolfia tetraphylla, Catharanthus roseus (uni- and multicellular) andCatharanthus pusillus (unicellular). Leaves ofWrightia tinctoria, Ervatamia divaricata andCatharanthus spp. are amphistomatic while those of other species are hypostomatic. Four stomatal types viz. anomo-, aniso-, tetra- and paracytic, occur in different combination patterns. Codominance of two stomatal types and their origin from unilabrate meristemoids isolateCatharanthus from other taxa. Its primitive nature is indicated by the unilabrate meristemoids.

Historical development of the present classification of morphological types of stomates

There is a long-standing confusion between morphologic and ontogenetic classifications of stomates. The earliest scheme, by Vesque (1889) was proposed as basically ontogenetic, but it was soon widely applied to mature leaves. The ontogenetic distinction between haplocheilic and syndetocheilic stomates in gymnosperms, proposed by Florin (1931, 1933) soon suffered a similar fate. Continuing studies over the past half-century have shown that stomatal ontogeny is only poorly correlated with the mature morphology. Efforts to combine ontogenetic and morphologic features in a single scheme have led to classifications so complex as to be impractical. The explicitly morphological classification by Metcalfe and Chalk (1950) is the foundation for the most widely used present scheme, in which some 14 morphological types are recognized. The distinctions among these types are conceptually useful, though often arbitrary in practice.

Stomatal morphology and ontogeny in Spirodela intermedia W. Koch

Stomatal morphology and ontogeny were studied in the epistomatic fronds of Spirodela intermedia W. Koch. Stomata in mature fronds do not form rows, but the orientation of their axis closely follows the veins; stomatal frequency increases gradually from a zone without stomata, near the proximal end, up to the margins all around the frond. Mature stomata are surrounded by between four and nine (generally six to seven) subsidiary cells, forming an irregular ring. They are classified as actinocytic or cyclocytic. Stomatal ontogeny was studied in small fronds, where three zones were delimited from the proximal to the distal end: meristematic, of stomatal initiation and differentiation, and of maturation. The ontogeny of the zone without stomata and of the stomata in the proximal part of the future mature fronds was studied in medium-sized fronds. The positional relationship of developing stomata with respect to the adaxial lobe of a two-lobed membrane covering the proximal part of the frond is established. It was not possible to see unequal divisions in the protodermal cells. Neighbouring cells of the guard-cell mother-cells divide in planes perpendicular and mostly parallel to the outline of the meristemoid. These divisions give rise to perigene subsidiary cells, although one or more of them may possibly be agene cells. The stomatal complex could thus be either euperigenous or hemiperigenous.

The interrelationship of growth substances and stomatal characters inGossypium hirsutum var H-777

Various types of stomatal abnormalities like persistent stomatal initials, single guard cells, degenerated guard cells and contiguous stomata with contiguity in different directions were recorded due to the treatment of different growth substances. Growth substances also altered the stomatal size, epidermal cell size, stomatal frequency, index and length-to-breadth ratio. It seems that the effect of these substances starts from the stomatal ontogeny and continue up to the last phase of development leading to such variations.

Epidermal structure and stomatal ontogeny in some Gymnosperms from Nigeria

Epidermal structure and stomatal ontogeny in some Gymnosperms from Nigeria

Epidermal structure and stomatal ontogeny in some Gymnosperms from Nigeria

Epidermal structure and stomatal ontogeny in some Gymnosperms from Nigeria

Structure and ontogeny of stomata on the vegetative and floral organs in nine species ofVerbena

The structure and ontogeny of stomata on the vegetative and floral organs in nine species ofVerbena are described. The data on stomatal index, density and size and epidermal cell density and size are also tabulated. Nine types of stomata occur side by side on the same surface in different combinations. The stomatal ontogeny is mesogenous, mesoperigenous and perigenous. Stomata with common subsidiary cells, cytoplasmic connections, cuticular striations, unequal guard cells, one guard cell and contiguous stomata are but sparingly observed. An increase in the number of subsidiary cells takes place by wall formation or the neighbouring perigenes assuming their shapes. Epidermal cells with inward projections are observed in the limb region of petals in all species. The taxonomic significance of stomata is also indicated.

Observations on the structure and ontogeny of stomata and trichomes on developing and mature pericarps ofCassia occidentalis L

Paracytic, anisocytic, anomocytic, transitional forms, tetracytic, cyclocytic stomata and partly and completely amphicyclic forms are found, often on the same surface, in nine combinations. The most frequent type is paracytic. A few morphological variations in the basic types and eight types of abnormalities in stomata are recorded. The stomatal ontogeny may be mesogenous, mesoperigenous or perigenous. Trichomes are multicellular glandular club-shaped and unicellular eglandular. The taxonomic significance of stomata is indicated.

Observations on the effects of morphactin EMD 7301 and EMD 7311 on the number, size, morphology and ontogeny of cotyledonary stomata ofAbelmoschus esculentus moench

Stomata on the cotyledons of Morphactin EMD 7301 and EMD 7311 treated seedlings may be anisocytic, anomocytic, paracytic, diacytio, transitional forms and haplocytic. In spite of this diversity, the most frequent type is anisocytic on both surfaces. The stomatal ontogeny may bo perigenous, mesogenous and mesoperigenous. Morphactin EMD 7301 and EMD 7311 increase the size of cotyledons in all concentrations accompanied by an increase in the number of stomata on the adaxial surface in 100, 150, 250 ppm of EMD 7301. The effect of morphactin is promotive to the size of stomata in all concentrations, but it retards the stomatal density and number of epidermal cells. This may be due to an increase in the size of the epidermal cells. The substrates, however, have no effect on the morphology and ontogeny of the stomata; probably they are inherent chracters.

Stomatogenesis in the genus Hibiscus L. (Malvaceae)

In Hibiscus, stomata are anisocytic, anomocytic, paracytic and tetracytic, the first type being the most frequent and occurring in all plant parts in the ten species studied, whereas the others are scarce and have a limited organographic distribution. The stem, petiole, pedicel, staminal tube, ovary and style are stomatiferous; the leaf-blade, stipule, bracteole and sepals are amphistomatic and petals hypostomatic in the species investigated. The stomatal types are often homoplastic, the anisocytic being either mesogenous trilabrate or mesoperigenous dolabrate, the anomocytic, mesoperigenous dolabrate or mesogenous trilabrate, and the tetracytic, mesoperigenous dolabrate or mesoperigenous trilabrate. But the typical paracytic stomata (with the subsidiaries completely enclosing the poles) are constantly mesogenous dolabrate and therefore probably indicate mesogenous dolabrate development. Although several patterns of stomatogenesis are encountered in any specific organ, only one of them is found to be dominant. A new subcategory of stomatal ontogeny, mesoperigenous trilabrate, is proposed in Hibiscus. No significant stomatal variation involving reduction in the divisive capacity of the meristemoid has been observed from the vegetative to floral parts; and stomata functioning as hydathodes have not been noticed in the latter, thus indicating that florogenic factors have no effect on the stomata.

Stomatal features ofHemionites arifolia (Burm.) Moore

Stomatal ontogeny and distribution in the Indian fernHemionites arifolia has been studied for the first time. The stomata conform to the mesoperigenousPlagiogyria type; a few stomata are diacytic.

The Cuticle, Epidermis and Stomatal Ontogeny of Casuarina equisetifolia Forst

The cuticle, epidermis and stomatal ontogeny of Casuarina equisetifolia Forst. is described. The cuticle shows well marked impressions of the epidermal cells and stomata. The epidermis of leaf and stem shows transversely oriented, tetracytic, mesoperigenous stomata with two lateral mesogene subsidiaries and two polar perigene neighbouring cells. Although the epidermal structure of Casuarina shows a good deal of resemblance with that of the Bennettitales, it may not indicate any phylogenetic relationships since there are important differences in the structure and reproduction of the plants of these two groups.