scholarly journals Floral Nectary Anatomy and Ultrastructure in Mycoheterotrophic Plant,Epipogium aphyllumSw. (Orchidaceae)

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Emilia Święczkowska ◽  
Agnieszka K. Kowalkowska
Keyword(s):  
Floral Biology ◽  
Tubular Structures ◽  
Dynamic Changes ◽  
Floral Nectary ◽  
Dense Bodies ◽  
Mycoheterotrophic Plants ◽  
Endocrine Secretion ◽  
Colour Form ◽  
Anatomy And Ultrastructure ◽  
Adaxial Cells

Epipogium aphyllumis a European-Asian obligatory mycoheterotrophic orchid containing no chlorophyll. Flowers are not resupinate with a sack-shape spur and cordate lip, which is divided into two parts: the basal (hypochile) and distal one (epichile). The floral analysis provides strong evidence to conclude that nectar is secreted on the upper surface of pink-coloured papillate ridges and epidermal (adaxial) cells at different place in spur, especially at the apex. The exudation on papillae has been observed through the entire anthesis and it has been stained on polysaccharides, proteins, and lipids. The dense cytoplasm of papillae contains profuse endoplasmic reticulum, plentiful vesicles (bigger ones with tannin-like materials), numerous mitochondria, sometimes dictyosomes, starch grains, and plastids with tubular structures. The large electron-dense bodies in cell walls are structurally the same as tannin-like materials from vesicles that are in contact with plasmalemma. The rupture of thin layer of swelled cuticle is caused by pressure of gathered substances exuded due to granulocrine secretion. The idioblasts with raphides occur mainly in tepals tissue. The dynamic changes of the nectar exudation, released through endocrine secretion, have been noticeable during the anthesis: both on the lip and inside the spur. The nectar secretion is not dependent on the colour form ofE. aphyllumblooming shoots. The floral biology and ultrastructure differ from mycoheterotrophic plants known up to date.

Nectary structure and nectar presentation in the Mediterranean geophyte, Urginea maritima (Hyacinthaceae)

Botany ◽  
2008 ◽  
Vol 86 (10) ◽  
pp. 1194-1204 ◽  
Author(s):  
Sharaf Al-Tardeh ◽  
Thomas Sawidis ◽  
Barbara-Evelin Diannelidis ◽  
Stylianos Delivopoulos
Keyword(s):  
Intermediate Stage ◽  
Secretory Cells ◽  
Urginea Maritima ◽  
Floral Nectary ◽  
Hydrolysis Process ◽  
Septal Nectary ◽  
Parenchyma Cells ◽  
Subsidiary Cells ◽  
Hydrolysis Of ◽  
Anatomy And Ultrastructure

The morphology, anatomy, and ultrastructure of the floral nectary of Urginea maritima (L.) Baker were investigated at three stages of nectary development. The plant possesses a typical gynopleural (septal) nectary with secondary presentation. The nectary consists of one layer of epithelium secretory cells and one to four layers of subsidiary cells subtended by two to six layers of parenchyma (subnectary) cells. The nectary releases the nectar at a point two-thirds towards the summit of the ovary by means of carpellary sutures. Nectar secretion appears to depend largely on the hydrolysis of starch grains stored in amyloplasts at the intermediate stage. The hydrolysis process most likely commences in the epithelium layer followed by the subsidiary tissue and then the parenchyma cells of the ovary wall. A symplastic transfer of the secreted nectar occurs by plasmodesmata connecting the subsidiary cells to the parenchyma and the epithelial secretory cells. However, microchannels in the cell wall of the epithelial cells may facilitate the apoplastic transfer of the nectar into the nectary cavity. The old stage of nectary development is characterized by a crystallized form of nectar, collapse of the parenchyma cells, complete starch hydrolysis, and disappearance of the amyloplasts and endoplasmic reticulum.

scholarly journals Pollination and Floral Biology of a Rare Morning Glory Species Endemic to Thailand, Argyreia siamensis

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2402
Author(s):  
Awapa Jirabanjongjit ◽  
Paweena Traiperm ◽  
Tomoki Sando ◽  
Alyssa B. Stewart
Keyword(s):  
Mating System ◽  
Floral Biology ◽  
Morning Glory ◽  
Pollinator Attraction ◽  
Secretory Structures ◽  
Floral Nectary ◽  
Population Sizes ◽  
Nectariferous Tissue ◽  
Effective Pollinators ◽  
Two Populations

Argyreia siamensis is extremely rare, and very little is known about its reproduction. The species has colorful flowers that seem likely to attract pollinators, but population sizes are typically small (<30 individuals). To determine whether poor reproduction contributes to its rarity, we investigated its mating system and potential pollinators in two populations. We also examined the staminal trichomes and floral nectary to investigate their role in pollinator attraction. The mating system was assessed with a bagging experiment and pollinator visits were recorded with action cameras. Additionally, we tested the staminal trichomes and floral nectary for terpenes and flavonoids and examined floral nectary micromorphology via scanning electron microscope and compound light microscope. Our results reveal that A. siamensis is self-incompatible and dependent on pollinators; the western population was pollinated by bees (Meliponini and Amegilla), while the eastern population was mainly pollinated by skipper butterflies (Hesperiidae). Both staminal trichomes and the floral nectary appear to contribute to pollinator attraction through the presence of terpenes and flavonoids (in both secretory structures) and nectariferous tissue and nectarostomata (in the nectary). Our results indicate that A. siamensis has reliable and effective pollinators and that insufficient pollination is likely not a primary cause of its rarity.

Studies on the ‘Incisures’ of Schmidt and Lanterman

1970 ◽  
Vol 6 (3) ◽  
pp. 767-791
Author(s):  
SUSAN M. HALL ◽  
P. L. WILLIAMS
Keyword(s):  
Endoplasmic Reticulum ◽  
Myelin Sheath ◽  
Post Mortem ◽  
Dynamic Changes ◽  
Dense Bodies ◽  
Fibre Growth ◽  
Electron Microscopical ◽  
Initial Description

Since its initial description over a century ago the ‘incisure‘ of Schmidt-Lanterman has usually been regarded as a histological artifact, or a post-mortem change. With the establishment of in vivo discrete zones in the myelin sheath, an ultrastructural study was undertaken and correlation attempted between their electron-microscopical appearances and their range of states seen in vivo and produced in vitro. It was demonstrated that under conditions of hypotonicity the incisure dilates and further that it closes in hypertonic solutions. Such behaviour is reversible within certain limits. Ultrastructurally, the incisural region appears as a highly complex zone in which the repeat characteristics of the compact myelin sheath are drastically altered. At the incisure, the major dense line of the myelin splits to enclose a granular Schwann cytoplasm which frequently contains a single central helical microtubule, dense bodies and small vesicles. The intraperiod line also splits, dilatation of the incisure involving further widening of this intraperiod line gap beyond the normal confines of the incisure. Desmosomoid stacks are a common feature, particularly of the outer layers of incisures of both mature and immature fibres. Surface invaginations, vesicles, longitudinal microtubules, filaments, mitochondria and granular endoplasmic reticulum are typical constituents of peri-incisural Schwann cytoplasm. The incisure may be related to fibre growth, remodelling and degeneration; to dynamic changes of internodal contour--possibly peristaltic; or may operate as a fluid-satellite cell-neuron interchange pathway.

Anatomy and ultrastructure of the floral nectary ofTontelea micrantha(Celastraceae: Salacioideae)

2015 ◽  
Vol 31 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Maria Olívia Mercadante-Simões ◽  
Elder Antônio Sousa Paiva
Keyword(s):  
Floral Nectary ◽  
Anatomy And Ultrastructure

Anatomy and ultrastructure of the floral nectary inPeganum harmalaL. (Nitrariaceae)

2012 ◽  
Vol 28 (3) ◽  
pp. 185-192 ◽  
Author(s):  
MASUMEH ABEDINI ◽  
ALI MOVAFEGHI ◽  
MAHBUBEH ALIASGHARPOUR ◽  
MOHAMMAD REZA DADPOUR
Keyword(s):  
Floral Nectary ◽  
Anatomy And Ultrastructure

scholarly journals Anatomy and ultrastructure of floral nectary of lnula helenium L (Asteraceae)

2011 ◽  
Vol 76 (3) ◽  
pp. 201-207 ◽  
Author(s):  
Aneta Sulborska ◽  
Elżbieta Weryszko-Chmielewska
Keyword(s):  
Secretory Cells ◽  
Secretory Vesicles ◽  
Nectar Secretion ◽  
Golgi Bodies ◽  
Floral Nectary ◽  
Granular Cytoplasm ◽  
Inula Helenium ◽  
Modified Stomata ◽  
Floral Nectaries ◽  
Anatomy And Ultrastructure

Floral nectaries of <em>Inula helenium</em> L. only occurred in disc florets and were situated above the inferior ovary. The shape of the investigated glands (five-armed star with rounded tips and deep incisions - observed from above) clearly differed from the shape of the nectaries of other <em>Asteraceae</em>, also the height of nectary was much lower (129 µm). The glandular tissue of the nectaries of elecampane was composed of a single-layered epidermis and 5--9 layers of secretory cells. Nectar was released through modified stomata, mainly arranged in the top part of the gland. The secretory cells were characterised by granular cytoplasm and the presence of a large, often lobate, cell nucleus. In the cytosol, numerous amoeboid plastids, mitochondria, Golgi bodies and ribosomes were present. In small vacuoles, myelin-like structures, fibrous material and vesicles with the content of substances which can be secretion, were observed. The plastid stroma showed different electron density and the presence of internal tubules and plastoglobules. Vesicular extensions forming bright zones were visible between the membranes of the nuclear envelope. Adjacent to the plasmalemma, as well as between the plasmalemma and the cell wall, secretory vesicles occurred, indicating the granulocrine mechanism of nectar secretion.

scholarly journals The structure of nectary of Platanthera bifolia L. Orchidaceae

2014 ◽  
Vol 66 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Małgorzata Stpiczyńska
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Secretory Cells ◽  
Floral Nectary ◽  
Secretory Tissue ◽  
Characteristic Features ◽  
Anatomy And Ultrastructure

The anatomy and ultrastructure of floral nectary of <em>Platanthera bifolia</em> were studied. The epidermis inside the nectary spur showed characteristic features of secretory tissue. Many cells of this epidermis were protruded forming unicellular hairs. The protoplasts of secretory cells were characterized by few small vacuoles, a lot of mitochondria and leucoplasts, which stored starch before secretion. Numerous vesicles budded off from the endoplasmic reticulum and the Golgi apparatus were accumulated near plasmalemma and fused with it. This fact probably indicates that these structures are involved in secretory processes. Nectar was released onto the surface through the pores in a ruptured cuticle, which covered the walls of secretory hairs.

Ultrastructural Cytopiasmic Changes of Adrenal Cortex During Pregnancy

1969 ◽  
Vol 27 ◽  
pp. 298-299
Author(s):  
T. M. Murad ◽  
Karen Israel ◽  
Jack C. Geer
Keyword(s):  
Adrenal Gland ◽  
Steroid Hormones ◽  
Adrenal Cortex ◽  
Lipid Droplets ◽  
Plasma Cholesterol ◽  
Adrenal Steroids ◽  
Dynamic Changes ◽  
Cortical Cells ◽  
Acetyl Coenzyme A ◽  
Adrenal Cortical Cells

Adrenal steroids are normally synthesized from acetyl coenzyme A via cholesterol. Cholesterol is also shown to enter the adrenal gland and to be localized in the lipid droplets of the adrenal cortical cells. Both pregnenolone and progesterone act as intermediates in the conversion of cholesterol into steroid hormones. During pregnancy an increased level of plasma cholesterol is known to be associated with an increase of the adrenal corticoid and progesterone. The present study is designed to demonstrate whether the adrenal cortical cells show any dynamic changes during pregnancy.

Ultrastructure of Liver in Lactosyl Ceramidosis

1971 ◽  
Vol 29 ◽  
pp. 312-313
Author(s):  
Z. Hruban ◽  
J. R. Esterly ◽  
G. Dawson ◽  
A. O. Stein
Keyword(s):  
Connective Tissue ◽  
Liver Biopsy ◽  
Osmium Tetroxide ◽  
Close Contact ◽  
Multivesicular Bodies ◽  
Bile Canaliculi ◽  
Dense Bodies ◽  
Marginal Plates ◽  
Membranous Material ◽  
Perichromatin Granules

Samples of a surgical liver biopsy from a patient with lactosyl ceramidosis were fixed in paraformaldehyde and postfixed in osmium tetroxide. Hepatocytes (Figs. 1, 2) contained 0.4 to 2.1 μ inclusions (LCI) limited by a single membrane containing lucid matrix and short segments of curved, lamellated and circular membranous material (Fig. 3). Numerous LCI in large connective tissue cells were up to 11 μ in diameter (Fig. 2). Heterogeneous dense bodies (“lysosomes”) were few and irregularly distributed. Rough cisternae were dilated and contained smooth vesicles and surface invaginations. Close contact with mitochondria was rare. Stacks were small and rare. Vesicular rough reticulum and glycogen rosettes were abundant. Smooth vesicular reticulum was moderately abundant. Mitochondria were round with few cristae and rare matrical granules. Golgi complex was seen rarely (Fig. 1). Microbodies with marginal plates were usual. Multivesicular bodies were very rare. Neutral lipid was rare. Nucleoli were small and perichromatin granules were large. Small bile canaliculi had few microvilli (Fig. 1).

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