scholarly journals Micro-morphological descriptions on Cenchrus species from Rajasthan (India)

2018 ◽  
Vol 7 (3) ◽  
pp. 2141
Author(s):  
Sunita Arora ◽  
Ganesh Kumar
Keyword(s):  
Environmental Conditions ◽  
Bundle Sheath ◽  
Extreme Conditions ◽  
Vascular Bundles ◽  
Thar Desert ◽  
C4 Plant ◽  
Starch Grains ◽  
Bulliform Cells ◽  
Famine Food ◽  
Large Vessels

Present investigation was carried out to screen micro-morphological features of Cenchrus species (C4 plant) belonging to family Poaceae. This is an important medicinal, fodder as well as crop plant and traditionally used as famine food during drought. It is best suited for desert environmental conditions.  In extreme conditions when food is in scarce, seeds of this grass are consumed by tribals. The microscopical illustrations revealed several interesting features i.e. presence of cuticle, bulliform cells, trichomes, lysigenous cavity, more amount of chlorenchyma, Y- shaped vascular bundles, double layered bundle sheath, large vessels and starch grains that support its assimilation efficacy and survival in typical conditions of Thar Desert. This study helps in referential identification, authentication, standardization and detection of adaptation strategies to understand biology of this plant.

scholarly journals Leaf blade and midrib anatomy of two sugarcane cultivars of Bangladesh

1970 ◽  
Vol 18 ◽  
pp. 66-73 ◽  
Author(s):  
N Joarder ◽  
AK Roy ◽  
SN Sima ◽  
K Parvin
Keyword(s):  
Leaf Blade ◽  
Bundle Sheath ◽  
Vascular Bundles ◽  
Abaxial Epidermis ◽  
Sugarcane Cultivar ◽  
Mestome Sheath ◽  
Bulliform Cells ◽  
Kranz Anatomy ◽  
Bundle Sheath Cells ◽  
Sheath Cells

Context: Kranz anatomy of locally developed sugarcane cultivars were studied in relation to C4 vascular arrangement.   Objective: The objective of this study was to make gross cross-sectional anatomy and quantitative assessment of the anatomic traits of the leaf-blade and midrib of the sugarcane cultivars.   Materials and Methods: Leaf blade and leaf sheath of two sugarcane cultivars Ishurdi 20 and Ishurdi 32 were used as the materials. Free hand section with appropriate stain were used. Sections were studied using an advanced biological system microscope fitted with motic camera. Anatomic traits were studied through motic image plus J 1.0 software using Macintosh computer.   Results: Three sized vascular bundles and significant differences in distance between those vascular bundles were noted. Ishurdi 32 possessed two sized vascular bundles. Large vascular bundles characters by two large metaxylem vessels on either side of protoxylem. Phloem well developed. Intermediate and small bundles lack metaxylem vessels and protoxylem, but have metaphloem with thick and thin walled sieve tubes. Bundle sheaths have extended to upper and lower epidermis but for small bundle it is extended to abaxial epidermis. Vascular bundles are almost completely surrounded by chlorenchymatous bundle sheath and associated with hypodermal sclerenchyma on both abaxially and adaxially except small blade bundles which associated with the abaxial sclerenchyma. Bundle sheath cells were smaller in large and larger in other two types of vascular bundle. An inner mestome sheath with thickened walls is always present round the phloem and metaxylem around all or part of the xylem in large and intermediate bundles. In small bundles mestome sheath is altogether absent. Bulliform cells with varied area were present on the adaxial epidermis opposite to small vascular bundles. Midrib anatomy consists of central large vascular bundles lacking bundle sheath cells pushed deep inside parenchymatous hypodermis from abaxial hypodermal sclerenchyma girders. Lack of Kranz traits, and bundle sheath cells have transformed into sclerenchymatous bundle cover. Central mid-rib large bundle flanked by 3-10 small bundles on either side of midrib which have Kranz system of anatomy. Midrib region have continuous hypodermis consists of sclerenchyma cells and it is few layer (Ishurdi 32) to multilayer (Ishurdi 20).   Conclusion: Kranz system with well developed bundle sheath associated with Kranz mesophil in the leaf blade were observed but Kranz tissue absent in midrib region. Large and small vascular bundles alternate all alone the leaf blade. Bulliform cell well develop indicates zeric adaptation. Two cultivars differ in respect of quantitative expression of Kranz tissue.   Keywords: Sugarcane cultivar; Kranz tissue; bulliform cells; mestome sheath. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8778 JBS 2010; 18(0): 66-73

scholarly journals Cross-sectional anatomy of leaf blade and leaf sheath of cogon grass (Imperata cylindrica L.)

2018 ◽  
Vol 25 ◽  
pp. 17-26
Author(s):  
SN Sima ◽  
AK Roy ◽  
MT Akther ◽  
N Joarder
Keyword(s):  
Vascular Bundle ◽  
Leaf Blade ◽  
Leaf Sheath ◽  
Bundle Sheath ◽  
Imperata Cylindrica ◽  
Saline Stress ◽  
Vascular Bundles ◽  
Bulliform Cells ◽  
Kranz Anatomy ◽  
Adaxial Epidermis

Histology of leaf blade and sheath of cogon grass (Imperata cylindrica L.) Beauv., indicated typical C4 Kranz anatomy. Cells of adaxial epidermis were smaller and bulliform cells were present on the adaxial epidermis. The shape of bulliform cells was bulbous; 3-7 cells were present in a group and 3-5 folds larger than epidermal cells. Three types of vascular bundles in respect of size and structure were extra large, large and small and they were part of leaf blade histology. These three sizes of vascular bundles were arranged in successive manner from midrib to leaf margin. Leaf sheath bundles were of two types: large and small. Extra large bundles were flanked by five small and four large bundles but small bundles were alternate found to be with large typed bundles. Extra large bundles were of typical monocotyledonous type but the large type had reduced xylem elements and the small typed was found to be transformed into treachery elements. Small be bundles occupied half the thickness of the flat portion of leaf blade topped by large bulliform cells of the adaxial epidermis. Extra large and large bundle had been extended to upper and lower epidermis. Kranz mesophyll completely encircled the bundle sheath and radiated out into ground tissue. Midrib was projected in abaxial direction and had a central vascular bundle with large and small bundles on either side of it along the abaxial regions. The midrib vascular bundle was devoid of chlorenchymatous bundle sheath and was of non-Kranz type. Continuous sub-epidermal sclerenchyma girders were noted as adaxial hypodermis. Anatomical traits exhibited an important adaptive defense against draught and saline stress of the plant. Quantitative measurement of various anatomical traits indicated strong variations among them.J. bio-sci. 25: 17-26, 2017

scholarly journals ESTUDO FARMACOBOTÂNICO DE FOLHAS DE CAPIM-LIMÃO: Cympobogon citratus (DC.) STAPF, POACEAE

2004 ◽  
Vol 5 (2) ◽  
Author(s):  
M. do R. Duarte ◽  
C. C. Zaneti
Keyword(s):  
Glandular Trichomes ◽  
Microscopic Analysis ◽  
Anatomical Study ◽  
Double Bundle ◽  
Bundle Sheath ◽  
Perennial Herb ◽  
Vascular Bundles ◽  
Cymbopogon Citratus ◽  
Bulliform Cells ◽  
Subsidiary Cells

Cymbopogon citratus (DC.) Stapf, Poaceae é uma erva aromática perene, conhecida popularmente como capim-limão. As folhas frescas ou dessecadas e o óleo extraído das mesmas são amplamente empregados na medicina tradicional e se lhes atribuem atividades sedativa, estomáquica, analgésica, antiespasmódica e antimicrobiana. Com o objetivo de complementar informações farmacognósticas, realizou-se estudo morfológico foliar externo (macroscópico) e anatômico (microscópico) da planta medicinal. Observou-se que as folhas apresentam formato linear-lanceolado, são planas, eretas e alternas, com bainha larga e nervação paralela. A epiderme é uniestratificada e constituída por células parenquimáticas e lignificadas; em vista frontal, apresentam formato retangular e paredes anticlinais levemente onduladas; ao longo da lâmina foliar são encontrados tricomas tectores unicelulares e bicelulares, e estômatos em formato de halteres, acompanhados de duas células subsidiárias. Células buliformes, clorênquima regular e feixes vasculares colaterais com estrutura Kranz, envoltos por bainha simples ou dupla estão presentes. Morpho-anatomical study of lemongrass leaVES: Cymbopogon citratus (DC.) STAPF, POACEAE Abstract This species is an aromatic perennial herb, commonly known as lemongrass. Their fresh or dried leaves and essential oil are largely employed in the traditional medicine as sedative, stomachic, analgesic, antispasmodic and antimicrobial. Aiming to contribute to pharmacognostical studies, morphological (macroscopic) and anatomical (microscopic) analysis were carried out. It was observed that the leaves have got linear-lanceolate shape; they are plain, erect and alternate, with a large sheathing base and parallel venation. The epidermis is composed by one layer of parenchymatic and sclerenchymatic cells, which shows elongated shape and slightly waved anticlinal walls; also present are uni- and bicellular non-glandular trichomes, and stomata surrounded by two subsidiary cells. Bulliform cells, homogeneous chlorenchyma and collateral vascular bundles, showing a wreath (Kranz structure) encircled by simple or double bundle sheath are described.

Modern problems of regionalization of territories and human adaptation in regions with extreme natural and climatic conditions

2021 ◽  
Author(s):  
A.L. Maksimov
Keyword(s):  
Environmental Factors ◽  
Environmental Conditions ◽  
Allostatic Load ◽  
Climatic Conditions ◽  
Extreme Conditions ◽  
Human Adaptation ◽  
Nonspecific Resistance ◽  
Key Words Adaptation ◽  
High Level ◽  
Selection Of

The paper considers modern approaches to the zoning of territories and the selection of people for life in extreme environmental conditions, taking into account modern geopolitical challenges. It is shown that it is possible, based on the allostasis concept, to conduct not only the selection of persons with a high level of nonspecific resistance, but also to quantify the degree of extremity of environmental factors using the standard represpiration test. Key words: adaptation, extreme conditions, selection, hypoxia, cold, rerespiration, allostatic load.

The distribution and ultrastructure of chloroplasts in leaves differing in photosynthetic carbon metabolism. I. Wheat, Sorghum, and Aristida (Gramineae)

1969 ◽  
Vol 47 (1) ◽  
pp. 15-21 ◽  
Author(s):  
T. Bisalputra ◽  
W. J. S. Downton ◽  
E. B. Tregunna
Keyword(s):  
Carbon Dioxide ◽  
Bundle Sheath ◽  
Vascular Bundles ◽  
Photosynthetic Pathway ◽  
Low Carbon ◽  
Mesophyll Cells ◽  
Cytological Evidence ◽  
Bundle Sheath Cells ◽  
Photosynthetic Carbon Metabolism ◽  
High Carbon Dioxide

The ultrastructure of the chlorenchymatous tissues around the vascular bundles of three different types of grass leaves is described. In the temperate grass leaf, as exemplified by wheat, the inner mestom sheath contains proplastids. Normal chloroplasts are found only within the mesophyll cells. Smaller chloroplasts occur in cells of the ill-defined parenchymatic bundle sheath. This type of leaf has the photosynthetic pathway described by Calvin and a high carbon dioxide compensation value. In the tropical grasses, Sorghum and Aristida, the new photosynthetic pathway proposed by Hatch et al. and low carbon dioxide compensation are correlated with development of the parenchymatic bundle sheath. Cytological evidence indicates that cells of the bundle sheath are much more active than the surrounding mesophyll tissue. The specialized chloroplasts of the bundle sheath cells may be responsible for the physiological and biochemical differences between leaves of tropical and temperate grasses.

Photosynthesis in Phosphoenolpyruvate Carboxykinase-Type C4 Species: Properties of Nad-Malic Enzyme From Urochloa panicoides

1987 ◽  
Vol 14 (5) ◽  
pp. 517 ◽  
Author(s):  
JN Burnell
Keyword(s):  
Malic Enzyme ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Bundle Sheath ◽  
Photosynthetic Pathway ◽  
C4 Plant ◽  
C4 Species ◽  
Absolute Requirement ◽  
Pep Carboxykinase ◽  
Fructose 1,6 Bisphosphate ◽  
Regulatory Properties

NAD-malic enzyme (EC 1.1.1.39) was purified from bundle sheath strands of Urochloa panicoides (a phosphoenolpyruvate carboxykinase-type C4 plant) and its kinetic and regulatory properties were investigated. The native enzyme has a molecular weight of about 470 000 and is an octomer composed of two slightly different monomers which occur in a 1 : 1 ratio. The enzyme has an absolute requirement for Mn2+, is stimulated by CoA, acetyl CoA, fructose 1,6-bisphosphate and SO42- and is inhibited by HCO3, oxaloacetate, 2-oxoglutarate and pyruvate. The enzyme is shown to be localised in the mito- chondria. The purified NAD-malic enzyme is unable to catalyse the carboxylation of pyruvate according to the reverse reaction. These findings are discussed in relation to the C4 photosynthetic pathway and its possible role in PEP carboxykinase-type C4 plants.

scholarly journals EFFECT OF SETHOXYDIM HERBICIDE IN THE LEAF ANATOMY AND PHYSIOLOGY OF BRACHIARIA GRASS UNDER WATER STRESS

2017 ◽  
Vol 35 (0) ◽  
Author(s):  
M.R.R. PEREIRA ◽  
A.R. MARTINS ◽  
D. MARTINS ◽  
G. SASSO ◽  
A.C. SILVA JR
Keyword(s):  
Water Stress ◽  
Leaf Anatomy ◽  
Room Temperature ◽  
Dry Mass ◽  
Negative Influence ◽  
Vascular Bundles ◽  
Bulliform Cells ◽  
Anatomy And Physiology ◽  
Urochloa Decumbens ◽  
Parenchymal Cells

ABSTRACT The goal of this study was to analyze the leaf anatomy and physiological behavior of Brachiaria grass plants (Urochloa decumbens) under different water conditions and with the application of sethoxydim herbicide. The used experimental design was the completely randomized one, with four replications, consisting of a 3 x 2 factorial scheme, with the combination of three water managements (-0.03, -0.07 and -1.5 MPa) with and without the application of sethoxydim herbicide + Assist mineral oil, at the recommended dose for the species (184 g a.i. ha-1). The assessed physiological and anatomicalal parameters were photosynthetic rate, stomatal conductance, transpiration, difference between leaf and room temperature, dry mass of plants, thickness of bulliform cells, adaxial and total epidermis. Under the conditions in which the experiment was conducted, it appears that Brachiaria grass leaves showed uniseriate epidermis, homogenous mesophyll, with radiated distribution of parenchymal cells around the vascular bundles. The adaxial epidermis presented bulliform cells; the vascular bundles are collateral and are present in different sizes. Water stress had a negative influence on herbicide effectiveness and decreased all physiological parameters. The application of the herbicide caused anatomical changes in plants with no water stress (-0.03 MPa), such as limitations in the growth of epidermic and bulliform cells, and in the total leaf thickness. However, in treatments with stress (-0.07 and -1.5 MPa), there were no differences in leaf anatomy, but an increase in the total thickness of leaves, probably as a result of the water stress conditions to which plants were submitted..

scholarly journals What are extreme environmental conditions and how do organisms cope with them?

2011 ◽  
Vol 57 (3) ◽  
pp. 363-374 ◽  
Author(s):  
John C. Wingfield ◽  
J. Patrick Kelley ◽  
Frédéric Angelier
Keyword(s):  
Environmental Conditions ◽  
Acute Stress ◽  
Extreme Environment ◽  
Target Cells ◽  
Extreme Conditions ◽  
Alpine Regions ◽  
The Individual ◽  
The Brain ◽  
Pituitary Adrenal Axis ◽  
Interaction With Receptors

Abstract Severe environmental conditions affect organisms in two major ways. The environment may be predictably severe such as in deserts, polar and alpine regions, or individuals may be exposed to temporarily extreme conditions through weather, presence of predators, lack of food, social status etc. Existence in an extreme environment may be possible, but then to breed or molt in addition can present major bottlenecks that have resulted in the evolution of hormone-behavior adaptations to cope with unpredictable events. Examples of hormone-behavior adaptations in extreme conditions include attenuated testosterone secretion because territoriality and excess courtship may be too costly when there is one opportunity to reproduce. The individual may even become insensitive to testosterone when target areas of the brain regulating reproductive behavior no longer respond to the hormone. A second example is reduced sensitivity to glucocorticoids following acute stress during the breeding season or molt that allows successful reproduction and/or a vital renewal of the integument to endure extreme conditions during the rest of the year. Reduced sensitivity could involve: (a) modulated response of the hypothalamo-pituitary-adrenal axis, (b) reduced sensitivity to high glucocorticoid levels, or (c) a combination of (a) and (b). Moreover, corticosteroid binding proteins (CBP) buffer responses to stress by reducing the movement of glucocorticoids into target cells. Finally, intracellular enzymes (11β-hydroxysteroid dehydrogenase and variants) can deactivate glucocorticoids entering cells thus reducing interaction with receptors. These mechanisms have important implications for climate change and increasing extremes of weather.

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