Cellular differentiation in small clumps of Lotus corniculatus callus

1983 ◽  
Vol 61 (2) ◽  
pp. 507-517 ◽  
Author(s):  
Melanie J. Howarth ◽  
R. L. Peterson ◽  
D. T. Tomes
Keyword(s):  
Cellular Differentiation ◽  
Morphological Changes ◽  
Callus Cultures ◽  
Leaf Primordia ◽  
Tracheary Elements ◽  
Apical Meristems ◽  
Suberin Lamellae ◽  
Phenolic Substances ◽  
Vacuolated Cells ◽  
Physiological Isolation

Lotus callus cultures were studied in an attempt to determine, at the cellular and subcellular levels, what morphological changes precede and accompany differentiation. Small clumps of homogenized callus were plated onto a medium containing benzyladenine, which was known to induce differentiation in this system. Initially callus was yellowish and consisted of large, vacuolated cells with deposits of starch. Marked changes occurred in these cells; peripheral and endogenous meristematic areas were initiated giving rise to shoots and either groups of tracheary elements or roots, respectively. Roots developed within 5 day s, while shoot apical meristems with leaf primordia formed by day 9. Many of the cells surrounding meristematic areas developed suberin lamellae in their walls, while others, both within and on the periphery of meristematic areas, accumulated phenolic substances. Cells within meristematic areas had large nuclei with prominent nucleoli, plastids with thylakoids but little or no starch, many mitochondria, and dictyosomes. Morphological observations tend to support the view that physiological isolation of tissue may precede differentiation.

scholarly journals Morphological Study of the Structure and Development of Longan Inflorescence

2005 ◽  
Vol 130 (6) ◽  
pp. 793-798
Author(s):  
Miki Nakata ◽  
Nobuo Sugiyama ◽  
Tanachai Pankasemsuk
Keyword(s):  
Morphological Study ◽  
Floral Induction ◽  
Leaf Primordia ◽  
Cool Season ◽  
Developmental Patterns ◽  
Apical Meristems ◽  
Naked Eye ◽  
Foliage Leaf ◽  
Dimocarpus Longan ◽  
Terminal Shoot

The structure and developmental patterns of inflorescence of longan (Dimocarpus longan Lour.) were studied microscopically and by the naked eye. In inflorescence of longan, compound dichasia are arranged on three to four orders of monopodial axes without the formation of terminal flowers, indicating that longan inflorescence is pleiothyrse; cymose partial inflorescences are arranged on more than two monopodial axes. Most of the monopodial axes had differentiated by the end of November just before the cool season. The first sign of inflorescence formation was the appearance of bract primordia at apical meristems of the preformed monopodial axes, with lateral axes preceding the main axes. Dichasia were formed in the axils of bract primordia, and the formation of bracts and dichasia continued. Bract appearance can be detected by the naked eye 1 week after microscopically detected bract appearance. Shoots with intermediate characteristics between the inflorescence and the vegetative shoots were formed; dichasia were formed on the lateral axes, but not on the main axes in intermediate shoots. These results suggest that apical meristems on the terminal shoot produce monopodial axes, together with foliage leaf primordia, before floral induction, but produce bract primordia and compound dichasia, which are composed of sympodial axes, after floral induction.

scholarly journals Graphene Oxide reinforced Agarose-Hydroxyapatite Bioprinted 3-D Scaffolds for Bone Regeneration

2021 ◽  
Author(s):  
Umakant Yadav
Keyword(s):  
Graphene Oxide ◽  
Cellular Differentiation ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Human Mesenchymal Stem Cells ◽  
3D Bioprinting ◽  
Promising Strategy ◽  
Morphogenetic Protein ◽  
Enhanced Expression ◽  
3D Printed

Three-dimensional (3D) bioprinting is an emerging technology for fabricating cells, biomaterials and extracellular matrix (ECM) into customized shapes and patterns. Here, we report additive manufacturing to create a customized 3D bioactive constructs for regenerative medicine. We have attempted to emphasize the use of agarose and graphene oxide as a promising material for the conceptualization of bioink unpaid to its unique physicochemical properties. The 3D printed structure is able to regenerating bone tissues and regulates the cellular differentiation without any significant morphological changes. The presence of graphene oxide enhances the osteoinductive behavior of the developed scaffolds, which is further supplemented by encapsulating human mesenchymal stem cells (hMSCs) on the 3D printed scaffolds. A significant enhanced expression of early osteogenic markers like morphogenetic protein (BMP), Runx-2, collagen-1, osteopontin, osteocalcin as well as mineralized ECM are observed on agarose-hydroxyapatite and graphene oxide 3D printed scaffolds compared to agarose-hydroxyapatite 3D printed scaffolds. Thus, the outcomes of the developed 3D bioprinted scaffolds provide a promising strategy for development of personalized bone grafts for tissue regeneration.

Enhancement of Submicroscopic Damage of the Nasal Epithelium by Topic Al Allergen Challenge in Patients with Perennial Nasal Allergy

2001 ◽  
Vol 110 (3) ◽  
pp. 236-242 ◽  
Author(s):  
Hideaki Motosugi ◽  
Kazuto Ohno ◽  
Hiroshi Nagata ◽  
Akiko Sanai ◽  
Tsutomu Numata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
Allergen Challenge ◽  
Nasal Epithelium ◽  
Nasal Allergy ◽  
Intercellular Spaces ◽  
Cytoplasmic Vacuoles ◽  
Nasal Hyperreactivity ◽  
Characteristic Features ◽  
Vacuolated Cells

The purposes of this study were to clarify whether damage of the nasal epithelium exists in patients with nasal allergy, and how the morphology of the epithelium changes after topical allergen challenge. Electron microscopy revealed 2 characteristic features in the nasal epithelium of patients with perennial nasal allergy — an increase in the number of epithelial cells with cytoplasmic vacuoles, and markedly widened intercellular spaces — although these changes were unclear under light microscopy. The density of vacuolated cells significantly increased 24 hours after allergen challenge. Further, the number of eosinophils that were associated with vacuolated cells was significantly higher in patients with nasal allergy than in controls. These morphological changes, thus, were considered to be types of damage to the nasal epithelium associated with nasal allergy. Such changes may be among the causes of nasal hyperreactivity, which is an important feature of nasal allergy.

Structure of a stem-derived callus of Ruta graveolens: meristems, leaves, and secretory structures

1978 ◽  
Vol 56 (21) ◽  
pp. 2717-2729 ◽  
Author(s):  
R. L. Peterson ◽  
M. G. Scott ◽  
B. E. Ellis
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Walls ◽  
Light And Electron Microscopy ◽  
Middle Lamella ◽  
Subsequent Development ◽  
Callus Cultures ◽  
Ruta Graveolens ◽  
Secretory Structures ◽  
Apical Meristems ◽  
Secretory Glands

Differentiation in a stem-derived callus of Ruta graveolens was studied by correlated light and electron microscopy. Shoot apical meristems, some of which initiated leaves, differentiated randomly at the surface of the callus. Some of the apical meristems had a tunica–corpus organization. Cells of the tunica and corpus had large nuclei with prominent nucleoli, small vacuoles, mitochondria, endoplasmic reticulum cisternae, and leucoplasts. The leaves were radial and had well developed stomata and chloroplasts of two types, one storing large starch grains and the other with no starch but with well developed grana. Lysigenous and schizolysigenous secretory glands were initiated in the leaves and towards the periphery of the callus. Central cells in the lysigenous glands underwent lysis forming a gland lumen into which lipid-like material from the degenerating cells was released. During early stages of cell lysis, breakdown of the middle lamella occurred, followed by the degeneration of cell walls. The lipid-like deposits are thought to be the essential oils known to be produced by these callus cultures. Schizolysigenous glands are formed by the separation of gland cells along the middle lamella and the subsequent development of an epithelial layer or layers surrounding a gland lumen. The cytology of epithelial cells was characterized by numerous ribosomes and the presence of plastids with lipid-like deposits, rough endoplasmic reticulum which occurred either as sheets of cisternae or tubular profiles, and osmiophilic deposits in the cytoplasm. Changes in the epithelial cell walls bordering on the gland lumen indicated that these cells were probably undergoing lysis in older stages of gland development.

scholarly journals Anatomical-morphological changes in Glyceria aquatica (L.) Wahlb. and Phalaris arundinacea L. growing in the zone inundated by the Kwiecko lake

2014 ◽  
Vol 56 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Eugeniusz R. Śpiewakowski ◽  
Maria Wielicka ◽  
Józef Piasecki
Keyword(s):  
Internal Structure ◽  
Hydroelectric Plant ◽  
Morphological Changes ◽  
Phalaris Arundinacea ◽  
Anthropogenic Factors ◽  
Vascular Bundles ◽  
Anatomical Changes ◽  
Apical Meristems ◽  
Lower Reservoir ◽  
Air Channels

Morphological-anatomical changes are described in the shoots of <em>Glyceria aquatica</em> and <em>Phalaris arundinacea</em>. These grasses encroach upon the zone inundated by the lake Kwiecko which is the lower reservoir of the Hydroelectric Plant Żydowo. The interaction of habitat and anthropogenic factors causes disturbances in the physiology of reproduction in the above mentioned plants and produces changes in their external and internal structure. Both species form in the zone inundated by the lake vegetative shoots exclusively, with profuse aerial tillering at the apical meristems. The morphological changes consist in shortening of the shoots and multiplication of the internodes. In the internal structure a narrowing of the ring of sclerenchyma, a shift of the vascular bundles into the sclerenchyma and an increase of its layer and air channels are observed.

scholarly journals FUSARIUM LATERITIUM CAUSES SWEETPOTATO CHLOROTIC LEAF DISTORTION.

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 855b-855
Author(s):  
C. A. Clark ◽  
R. A. Valverde ◽  
J. A. Wilder-Ayers ◽  
P. E. Nelson
Keyword(s):  
Leaf Primordia ◽  
Apical Meristems ◽  
Fusarium Lateritium ◽  
Leaf Surfaces ◽  
Meristem Tip Culture ◽  
Chlorotic Leaf ◽  
Sunny Weather ◽  
Leaf Distortion ◽  
White Material ◽  
Fungal Mycelia

Symptoms of chlorotic leaf distortion (CLD) develop on vigorously growing sweetpotato (Ipomoea batatas) plants during sunny weather. They include chlorosis and twisting of young, expanding leaves and the appearance of white material on the adaxial leaf surfaces. The white material consisted of extramatrical fungal mycelia and Fusarium macroconidia. Fusarium lateritium Nees was isolated from surface-sterilized vine segments, leaf primordia, apical meristems, flower parts and true seeds of plants with CLD. Meristem-tip-culture-derived plants (mericlones) did not develop symptoms when grown for extended periods under disease-conducive conditions in the greenhouse. The fungus was not isolated from mericlones or other plants which had remained symptomless in the greenhouse but was isolated from lower nodes of symptomless plants from growers' fields. Symptoms developed on 84% of 185 mericlones of nine sweetpotato genotypes inoculated with F. lateritium isolated from CLD-affected plants. The pathogen was reisolated only from inoculated mericlones.

scholarly journals Adventitious Bud Formation from Callus Cultures of Japanese Persimmon

HortScience ◽  
1992 ◽  
Vol 27 (3) ◽  
pp. 259-261 ◽  
Author(s):  
Ryutaro Tao ◽  
Akira Sugiura
Keyword(s):  
High Frequency ◽  
Callus Cultures ◽  
Leaf Primordia ◽  
Adventitious Bud ◽  
Diospyros Kaki ◽  
Naphthaleneacetic Acid ◽  
Adventitious Buds ◽  
Japanese Persimmon ◽  
Adventitious Bud Formation ◽  
Young Leaves

Callus cultures were initiated in the dark from leaf primordia, stem internodes, and young leaves of adult Japanese persimmon (Diospyros kaki L.) to induce adventitious buds. A high frequency of regeneration occurred on Murashige and Skoog medium (MS) with half the normal NH4NO3 and KNO3 concentration (1/2N) and containing 10 μm zeatin or 1 μm 4PU-30 in combination with 0.1 μm IAA, or MS(1/2N) medium containing 0.03 to 0.1 μ m IAA or 0.01 to 0.03 μm NAA combined with 10 μm zeatin. No significant differences in the capacity of regeneration were observed among the calli from different explant sources. Only eight of 16 cultivars formed adventitious buds on MS(1/2N) medium containing 10 μm zeatin and 0.1 μm IAA, with the percentage of explants forming adventitious buds ranging from 2% to 72%. Chemical names used: indole3-acetic acid (IAA); 1-naphthaleneacetic acid (NAA); N-phenyl-N'-(2-chloro-4-pyridyl)urea (4PU-30).

ANALYSIS OF THE HISTOCHEMICAL LOCALIZATION OF PEROXIDASE RELATED TO THE DIFFERENTIATION OF PLANT TISSUES

1959 ◽  
Vol 37 (3) ◽  
pp. 449-458 ◽  
Author(s):  
D. S. Van Fleet
Keyword(s):  
Cell Division ◽  
Nucleic Acids ◽  
Future Development ◽  
Continuous System ◽  
Leaf Primordia ◽  
Plant Tissues ◽  
Spiral Pattern ◽  
Adult Tissue ◽  
Bud Formation ◽  
Apical Meristems

Peroxidase is detectible in all tissues but is most reactive, in the basophilic cells of the histogens. Oxidation of applied phenols and aminophenols by peroxidase produces quinones and quinonediimines that are adsorbed by nucleic acids and other basophilic substances in the formative centers of primordia. Localized reactions for peroxidase occur in the axils of leaf primordia prior to bud formation and on the surface of apical meristems in a spiral pattern marking the points for the future development of leaf primordia. Peroxidase is detectible in advance of or accompanying cell division and declines after the division phase; decline of peroxidase at the end of the division phase is related to the increase of phenols, naphthols, and phenolases. Peroxidase declines in all tissues except the phloem; a continuous peroxidase system in the phloem connects primordia with adult tissue. The hypothesis is offered that the cellular units of the phloem peroxidase constitute a continuous system between primordia and adult tissue and is functional in catalyzing the reduction of hydrogen acceptors essential to cell division and the initiation of primordia.

Morphological Changes in the Rat Granulosa Cell Surface During Differentiation Induced by Estradiol and Gonadotropins

1977 ◽  
Vol 35 ◽  
pp. 484-485
Author(s):  
P. Bagavandoss ◽  
JoAnne S. Richards ◽  
A. Rees Midgley
Keyword(s):  
Cell Surface ◽  
Granulosa Cell ◽  
Morphological Changes ◽  
Follicular Development ◽  
Female Rats ◽  
Functional Changes ◽  
Group 4 ◽  
Group 3 ◽  
Group 5 ◽  
Group 2

During follicular development in the mammalian ovary, several functional changes occur in the granulosa cells in response to steroid hormones and gonadotropins (1,2). In particular, marked changes in the content of membrane-associated receptors for the gonadotropins have been observed (1).We report here scanning electron microscope observations of morphological changes that occur on the granulosa cell surface in response to the administration of estradiol, human follicle stimulating hormone (hFSH), and human chorionic gonadotropin (hCG).Immature female rats that were hypophysectcmized on day 24 of age were treated in the following manner. Group 1: control groups were injected once a day with 0.1 ml phosphate buffered saline (PBS) for 3 days; group 2: estradiol (1.5 mg/0.2 ml propylene glycol) once a day for 3 days; group 3: estradiol for 3 days followed by 2 days of hFSH (1 μg/0.1 ml) twice daily, group 4: same as in group 3; group 5: same as in group 3 with a final injection of hCG (5 IU/0.1 ml) on the fifth day.

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