scholarly journals Study of epidermis characters and venation of certain species of Medicago L. in Leguminosae (Fabaceae) family in Iraq

2017 ◽  
Vol 14 (3) ◽  
pp. 479-488
Author(s):  
Baghdad Science Journal
Keyword(s):  
Cell Size ◽  
Guard Cell ◽  
Anatomical Study ◽  
Guard Cells ◽  
Lower Surface ◽  
Diagnostic Value ◽  
Stomatal Complexes ◽  
Vertical Walls ◽  
Subsidiary Cells

The anatomical study of the epidermis leaflet for seven species and variety wild belonging to the genus Medicago L. species are: M. constricta Dur., M. coronata L., M. intertexta L., M. intertexta.var. ciliaris L., M. laciniata L., M. lupulina L., M. minima L. and M. sativa L. were studied, The search included epidermis characters and stomatal complexes addition to venation system in leaflets. It is revealed through the study, epidermis leaflet type Amphistomatic (the stomata spread on the upper and lower surface) as well as the presence of three types of stomatal complexes namely: Anisocytic (the guard cells surrounded by three unequal cell size), Anomocytic (not differential from subsidiary cells in epidermis) and Anomotetracytic (four cells surrounding the guard cell is irregular and varied). The results showed variations in dimensions and forms stomata and nature vertical walls and tangent to the upper and lower surfaces. The venation system distinguish by all the species studied as one of the type Simple craspedodromous in this system all secondary veins and branching ends at the margin of the blade leaflets, this found in all species. But there are clear differences in the Areoles shape and type of vienlets and at the ends, where these characters taxonomic and diagnostic value of the task in the species under study.

A Scanning Electron Microscope Study of Isolated Guard Cells

1973 ◽  
Vol 31 ◽  
pp. 454-455 ◽  
Author(s):  
P. Dayanandan ◽  
P. B. Kaufman
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Three Dimensional ◽  
Guard Cells ◽  
Scanning Electron Microscope Study ◽  
Psilotum Nudum ◽  
Subsidiary Cells ◽  
Welwitschia Mirabilis ◽  
Cycas Revoluta ◽  
Scanning Electron

A three dimensional appreciation of the guard cell morphology coupled with ultrastjuctural studies should lead to a better understanding of their still obscure dynamics of movement. We have found the SEM of great value not only in studies of the surface details of stomata but also in resolving the structures and relationships that exist between the guard and subsidiary cells. We now report the isolation and SEM studies of guard cells from nine genera of plants.Guard cells were isolated from the following plants: Psilotum nudum, four species of Equisetum, Cycas revoluta, Ceratozamia sp., Pinus sylvestris, Ephedra cochuma, Welwitschia mirabilis, Euphorbia tirucalli and Allium cepa.

Osmocytosis and Vacuolar Fragmentation in Guard Cell Protoplasts: Their Relevance to Osmotically-lnduced Volume Changes in Guard Cells

1993 ◽  
Vol 44 (10) ◽  
pp. 1569-1577 ◽  
Author(s):  
WILFRIED DIEKMANN ◽  
RAINER HEDRICH ◽  
KLAUS RASCHKE ◽  
DAVID G. ROBINSON
Keyword(s):  
Guard Cell ◽  
Guard Cells ◽  
Volume Changes ◽  
Guard Cell Protoplasts

Cryogenic thermal insulating and mechanical properties of rigid polyurethane foams blown with hydrofluoroolefin: Effect of perfluoroalkane

2021 ◽  
pp. 0021955X2110626
Author(s):  
Tae Seok Kim ◽  
Yeongbeom Lee ◽  
Chul Hyun Hwang ◽  
Kwang Ho Song ◽  
Woo Nyon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Cell Size ◽  
Thermal Insulation ◽  
Coefficient Of Thermal Expansion ◽  
Lower Surface ◽  
Polyurethane Foams ◽  
Insulation Material ◽  
Pu Foams

The effect of perfluoroalkane (PFA) on the morphology, thermal conductivity, mechanical properties and thermal stability of rigid polyurethane (PU) foams was investigated under ambient and cryogenic conditions. The PU foams were blown with hydrofluorolefin. Morphological results showed that the minimum cell size (153 μm) was observed when the PFA content was 1.0 part per hundred polyols by weight (php). This was due to the lower surface tension of the mixed polyol solution when the PFA content was 1.0 php. The thermal conductivity of PU foams measured under ambient (0.0215 W/mK) and cryogenic (0.0179 W/mK at −100°C) conditions reached a minimum when the PFA content was 1.0 php. The low value of thermal conductivity was a result of the small cell size of the foams. The above results suggest that PFA acted as a nucleating agent to enhanced the thermal insulation properties of PU foams. The compressive and shear strengths of the PU foams did not appreciably change with PFA content at either −170°C or 20°C. However, it shows that the mechanical strengths at −170°C and 20°C for the PU foams meet the specification. Coefficient of thermal expansion, and thermal shock tests of the PU foams showed enough thermal stability for the LNG carrier’s operation temperature. Therefore, it is suggested that the PU foams blown by HFO with the PFA addition can be used as a thermal insulation material for a conventional LNG carrier.

ONTOGENY OF STOMATA IN SOME CRUCIFERAE

1967 ◽  
Vol 45 (4) ◽  
pp. 495-500 ◽  
Author(s):  
G. S. Paliwal
Keyword(s):  
Guard Cells ◽  
Vertical Division ◽  
Subsidiary Cells

The ontogeny of stomata was investigated in 12 species of Cruciferae. The three subsidiary cells as well as the guard cells originate from the same protodermal cell and thus the ontogeny conforms to the syndetocheilic type. The mature stomata are anisocytic. Sometimes, the subsidiary cells undergo a transverse and (or) vertical division and the mature stoma shows four to five subsidiary cells.

Fossil flowers and leaves of the Ebenaceae from the Eocene of southern Australia

1985 ◽  
Vol 63 (10) ◽  
pp. 1825-1843 ◽  
Author(s):  
James F. Basinger ◽  
David C. Christophel
Keyword(s):  
Guard Cells ◽  
Epidermal Cells ◽  
Fossil Leaves ◽  
Extant Species ◽  
Late Tertiary ◽  
The Family ◽  
Fossil Flowers ◽  
Subsidiary Cells ◽  
Clay Lenses ◽  
Coal Measures

Numerous flowers and a diverse assemblage of leaves are mummified in clay lenses in the base of the Demons Bluff Formation overlying the Eastern View Coal Measures. Fossil localities occur in the Alcoa of Australia open cut near Anglesea, Victoria, Australia. Flowers are tubular, less than 10 mm long, and about 5 mm wide. Four sepals are connate forming a cup-shaped calyx. Four petals are fused in their basal third and alternate with sepals. Flowers are all unisexual and staminate. Stamens are epipetalous and consistently 16 in number, arranged in 8 radial pairs. Pollen is subprolate, tricolporate, and about 32 μm in diameter. The exine is smooth to slightly scabrate. A rudimentary ovary occurs in some flowers. Sepals usually have a somewhat textureless abaxial cuticle with actinocytic stomata. Some sepals, however, have frill-like cuticular thickenings over some abaxial epidermal cells and some subsidiary cells with pronounced papillae overarching guard cells. One of the more common leaf types found associated with the flowers is characterized by the same peculiar cuticular thickenings and overarching papillae on subsidiary cells that occur on sepals. This cuticular similarity indicates that flowers and leaves represent a single taxon. Leaves are highly variable in size and shape but are consistently entire margined, with pinnate, brochidodromous venation. The suite of features characterizing the flowers is unique to the Ebenaceae. Flowers of many extant species of Diospyros (Ebenaceae) closely resemble the fossil flowers. Fossil leaves, too, are typical of leaves of extant Diospyros. Both flowers and leaves are considered conspecific and have been assigned the name Austrodiospyros cryptostoma gen. et sp. nov. The Anglesea fossils represent one of the earliest well-documented occurrences of the Ebenaceae and are the earliest known remains of Ebenaceae from Australia. They support the hypothesis of a Gondwanan origin for the family with late Tertiary diversification in the Malesian region.

Anatomy of two species of Plumbago : a traditional medicinal plant and its relevance for taxonomy

2021 ◽  
Vol 27 (2) ◽  
Author(s):  
Smita Chaudhari
Keyword(s):  
Medicinal Plant ◽  
Anatomical Study ◽  
Diagnostic Value ◽  
Epidermal Cells ◽  
Vascular Bundles ◽  
Taxonomic Significance ◽  
Anatomical Features ◽  
Leaf Petiole ◽  
Abundance And Distribution ◽  
Shape And Size

Plumbago is a traditional medicinal plant in Ayurveda. The paper presents anatomical study of leaf, petiole, stem and root of two species of Plumbago namely P. zeylanica, P. auriculata and, its relevance in discrimination of these two species. Anatomical features of leaf which are of diagnostic value in delimitation of both taxa are outline of T. S.,shape and size of epidermal cells, presence of sclerenchyma surrounding the vascular bundles, number of tannins cells. Characters of taxonomic significance in petiole anatomy are outline of T. S, presence of trichomes, shape and size of epidermal cells, abundance of collenchyma, arrangement and number of vascular bundles, presence of sclerenchyma surrounding vascular bundles, number of tannin cells. The diagnostically useful anatomical features of stem to discriminate both taxa of Plumbago are degree of elevation of stem ridges, occurrence of double layered epidermis, size of epidermal cells, distinctness of endodermis, abundance and distribution of pericyclicsclerenchyama, number of vascular bundles. Anatomical features of taxonomic significance in root are width of cortex and abundance of starch grains in cortex cells, abundance and distribution of pericyclics clerenchyama, amount of vascularization, distribution, diameter and density of vessels, width of medullary ray.

scholarly journals Guard Cell Microfilament Analyzer Facilitates the Analysis of the Organization and Dynamics of Actin Filaments in Arabidopsis Guard Cells

2019 ◽  
Vol 20 (11) ◽  
pp. 2753
Author(s):  
Xin Li ◽  
Min Diao ◽  
Yanan Zhang ◽  
Guanlin Chen ◽  
Shanjin Huang ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Dynamic Behavior ◽  
Guard Cell ◽  
Actin Filaments ◽  
De Novo ◽  
Guard Cells ◽  
Stomatal Movement ◽  
Selection Of

The actin cytoskeleton is involved in regulating stomatal movement, which forms distinct actin arrays within guard cells of stomata with different apertures. How those actin arrays are formed and maintained remains largely unexplored. Elucidation of the dynamic behavior of differently oriented actin filaments in guard cells will enhance our understanding in this regard. Here, we initially developed a program called ‘guard cell microfilament analyzer’ (GCMA) that enables the selection of individual actin filaments and analysis of their orientations semiautomatically in guard cells. We next traced the dynamics of individual actin filaments and performed careful quantification in open and closed stomata. We found that de novo nucleation of actin filaments occurs at both dorsal and ventral sides of guard cells from open and closed stomata. Interestingly, most of the nucleated actin filaments elongate radially and longitudinally in open and closed stomata, respectively. Strikingly, radial filaments tend to form bundles whereas longitudinal filaments tend to be removed by severing and depolymerization in open stomata. By contrast, longitudinal filaments tend to form bundles that are severed less frequently in closed stomata. These observations provide insights into the formation and maintenance of distinct actin arrays in guard cells in stomata of different apertures.

scholarly journals Preparation of Rolled Epidermis of Vicia Faba L. So That Stomata are the Only Viable Cells: Analysis of Guard Cell Potassium by Flame Photometry

1973 ◽  
Vol 26 (2) ◽  
pp. 309 ◽  
Author(s):  
WG Allaway ◽  
TC Hsiao
Keyword(s):  
Vicia Faba ◽  
Guard Cell ◽  
Guard Cells ◽  
Flame Photometry ◽  
Viable Cells ◽  
Rolling Technique ◽  
Vicia Faba L

A rolling technique is described with which cells in epidermal strips of V. faba were differentially broken so that only guard cells remained alive and functional. In rolled epidermis potassium was retained only in live guard cells, as judged by staining with cobaltinitrite.

scholarly journals Auxin as an inducer of asymmetrical division generating the subsidiary cells in stomatal complexes ofZea mays

2015 ◽  
Vol 10 (3) ◽  
pp. e984531 ◽  
Author(s):  
Pantelis Livanos ◽  
Eleni Giannoutsou ◽  
Panagiotis Apostolakos ◽  
Basil Galatis
Keyword(s):  
Stomatal Complexes ◽  
Asymmetrical Division ◽  
Subsidiary Cells

The occurrence of functional non-chlorophyllous guard cells in Paphiopedilum spp.

1975 ◽  
Vol 53 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sherman D. Nelson ◽  
James M. Mayo
Keyword(s):  
Fluorescence Microscopy ◽  
Blue Light ◽  
Guard Cell ◽  
Direct Evidence ◽  
Light Response ◽  
Guard Cells ◽  
Epidermal Cells ◽  
Stomatal Response ◽  
Intact Leaves ◽  
Stomatal Functioning

Hypostomatous lady slipper orchids, Paphiopedilum spp., were found to have non-chlorophyllous epidermal cells, including guard cells. The lack of chlorophyll within the guard cells was demonstrated by fluorescence microscopy. A "normal" chlorophyllous mesophyll was present. The leaf resistances of intact leaves were about 5–10 s cm−1 in the light and were greater than 100 s cm−1 in the dark, indicating light opening and dark closure of the stomata. A CO2-dependent stomatal response (i.e., a tendency to close at elevated CO2 levels) was demonstrated, as was a CO2-independent light response (i.e., greater opening in blue light than in red). This provides direct evidence to support the idea that guard cell chlorophyll is not necessary for stomatal functioning.

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