Conidiogenesis in Oidiodendron periconioides and ultrastructure of ericoid mycorrhizas formed with Rhododendron brachycarpum

1993 ◽  
Vol 71 (11) ◽  
pp. 1481-1485 ◽  
Author(s):  
R. S. Currah ◽  
A. Tsuneda ◽  
S. Murakami
Keyword(s):  
Complex System ◽  
Physiological Role ◽  
Epidermal Cells ◽  
Peat Moss ◽  
Ericoid Mycorrhiza ◽  
Hair Roots ◽  
Oidiodendron Maius ◽  
Ericoid Mycorrhizas ◽  
Scanning Electron

Oidiodendron periconioides was isolated from hair roots of seedlings of Rhododendron brachycarpum growing in pots containing a commercial peat moss in Japan. The unusual process of conidiogenesis in O. periconioides involved the formation of conidia from vesicle-like swellings that developed from vegetative hyphae or from the apex of a mononematous conidiophore. Scanning electron microscope examinations of mature conidia revealed that they were regularly dimpled, giving them the characteristic and previously reported radiate pattern of sculpturing visible with the light microscope. Oidiodendron periconioides formed ericoid mycorrhizas that were morphologically and ultrastructurally similar to previously studied ericoid systems involving Oidiodendron maius and Hymenoscyphus ericae, and a few other species of Rhododendron. Rough-walled hyphae grew appressed to the epidermal cells of young hair roots, penetrated the external walls via narrow penetration tubes, and invaginated the plasma membrane of the host cell during the process of forming a complex system of hyphal loops. Infection was restricted to the zone proximal to the active region of the meristem. Hyphal complexes were short-lived and degenerated as the epidermal cells matured and died. The physiological role of O. periconioides as a mycorrhizal endophyte is unknown. Key words: ericoid mycorrhiza, Oidiodendron periconioides, Rhododendron brachycarpum, conidiogenesis.

scholarly journals The structure of septal nectaries and nectar presentation in the flowers of Allium aflatunense B. Fedtsch.

2012 ◽  
Vol 62 (2) ◽  
pp. 31-41 ◽  
Author(s):  
Beata Żuraw ◽  
Elżbieta Weryszko-Chmielewska ◽  
Halina Laskowska ◽  
Elżbieta Pogroszewska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Epidermal Cells ◽  
Scanning Electron

The location and structure of the septal nectaries in the flowers of <i>Allium aflatunense</i> B. Fedtsch. were studied. Light and scanning electron microscopy were used for examination. It has been shown that the septal nectaries are located in the lower part of the ovary and in the gynophore on which the ovary is borne. Nectar is secreted through the single-layered epidermis surrounding three nectary slits and nectar release occurs through three openings located at the base of the gynophore, which are the outlets of the ducts connected to the nectary slits. The expanded and fused bases of the stamen filaments and the tepals participate in secondary nectar presentation. In the flowers of <i>Allium aflatunense</i>, numerous purple elements: tepals, filaments, style and pedicle, perform the role of a colour attractant. On the intensely green ovary, there occur glistening conical outgrowths of epidermal cells, which may also function as signal attractants.

Ultrastructure of Mycorrhizas of Dracophyllum secundum R. Br. (Ericales:Epacridaceae)

1989 ◽  
Vol 16 (1) ◽  
pp. 147 ◽  
Author(s):  
WK Allen ◽  
WG Allaway ◽  
GC Cox ◽  
PG Valder
Keyword(s):  
Structural Integrity ◽  
Fungal Endophytes ◽  
Mycorrhizal Fungus ◽  
Fungal Endophyte ◽  
Epidermal Cells ◽  
Root Cells ◽  
Hair Roots ◽  
Ericoid Mycorrhizas ◽  
Hyphal Coils ◽  
Plant Plasma Membrane

Dracophyllum secundum R. Br. (Epacridaceae) often possessed ericoid mycorrhizas; fungal endophytes formed coils within cells of the epidermis of hair-roots. The plant plasma membrane extended around the hyphae. In some epidermal cells of hair-roots, both plant and fungal cells retained their structural integrity, both partners showing mitochondrial, vacuolar and lipid droplet profiles, and with much of the plant cytoplasm associated with the hyphal coils. In other epidermal cells of hair-roots, fungal coils were present but cytoplasmic features of both symbionts appeared to have broken down. Some epidermal cells showed no evidence of fungal infection. These three arrangements could occur in root-cells of the same age, and are interpreted as resulting from different stages in the development and degeneration of the infection by the mycorrhizal fungus. Two structural types of fungal endophyte here found in ericoid mycorrhizas in D. secundum: one with simple septa, Woronin bodies and two-layered walls (presumed to be an Ascomycete), and another with dolipore septa with imperforate parenthesomes (presumed to be a Basidiomycete). The possibilities that the mycorrhizas may be seasonal, and that mycorrhizal status varies from place to place, are discussed.

scholarly journals Scanning Electron Microscopic Studies of the Pecten Oculi in the Quail (Coturnix coturnix japonica)

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Aris F. Pourlis
Keyword(s):  
Functional Anatomy ◽  
Physiological Role ◽  
Coturnix Japonica ◽  
Electron Microscopic ◽  
Coturnix Coturnix ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Pecten Oculi ◽  
Scanning Electron

The main purpose of this study is to extend the microscopic investigations of the pecten oculi in the quail in order to add some information on the unresolved functional anatomy of this unique avian organ. The pecten oculi of the quail was studied by scanning electron microscopy. Eighteen- to-twenty two highly vascularised accordion-like folds were joined apically by a heavily pigmented bridge of tissue, which holds the pecten in a fanlike shape, widest at the base. The structure of the double layered limiting membrane was recorded. The presence of hyalocytes with macrophage-like appearance was illustrated. It is assumed that the pecten oculi of the quail resembles that of the chicken. Illustrated morphological features of this species may add information on the active physiological role of the pecten. But still, the functional significance of this organ is a matter of controversies.

The use of scanning electron microscopy in interpreting chenopodium remains from three archaeological sites in northwestern Iowa

1992 ◽  
Vol 50 (2) ◽  
pp. 1112-1113
Author(s):  
Douglas William Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Archaeological Sites ◽  
Late Prehistoric ◽  
Eastern United States ◽  
Chenopodium Berlandieri ◽  
Seed Identification ◽  
Level 2 ◽  
Scanning Electron

Within the past 20 years, archaeobotanical research in the Eastern United States has documented an early agricultural complex before the dominance of the Mesoamerican domesticates (corn, beans, and squash) in late prehistoric and historic agricultural systems. This early agricultural complex consisted of domesticated plants such as Iva annua var.macrocarpa (Sumpweed or Marshelder), Hellanthus annuus (Sunflower) and Chenopodium berlandieri, (Goosefoot or Lasbsquarters), and heavily utilized plants such as Polygonum erectum (Erect Knotweed), Phalaris caroliniana (May grass), and Hordeum pusillum (Little Barley).Recent research involving the use of Scanning Electron Microscopy (SEM) specifically on Chenopodium has established diagnostic traits of wild and domesticated species seeds. This is important because carbonized or uncarbonized seeds are the most commonly recovered Chenopodium material from archaeological sites. The diagnostic seed traits assist archaeobotanists in identification of Chenopodium remains and provide a basis for evaluation of Chenopodium utilization in a culture's subsistence patterns. With the aid of SEM, an analysis of Chenopodium remains from three Late Prehistoric sites in Northwest Iowa (Blood Run [Oneota culture], Brewster [Mill Creek culture], and Chan-Ya-Ta [Mill Creek culture]) has been conducted to: 1) attempt seed identification to a species level, 2) evaluate the traits of the seeds for classification as either wild or domesticated, and 3) evaluate the role of Chenopodium utilization in both the Oneota and Mill Creek cultures.

Physiological Role of Cyclic Electron Flow in Higher Plants

2012 ◽  
Vol 30 (1) ◽  
pp. 100
Author(s):  
Wei HUANG ◽  
Shi-Bao ZHANG ◽  
Kun-Fang CAO
Keyword(s):  
Higher Plants ◽  
Electron Flow ◽  
Physiological Role ◽  
Cyclic Electron Flow

The Renal Outer Medullary Potassium Channel (ROMK): An Intriguing Pharmacological Target for an Innovative Class of Diuretic Drugs

2018 ◽  
Vol 25 (23) ◽  
pp. 2627-2636 ◽  
Author(s):  
Vincenzo Calderone ◽  
Alma Martelli ◽  
Eugenia Piragine ◽  
Valentina Citi ◽  
Lara Testai ◽  
...  
Keyword(s):  
Physiological Role ◽  
Clinical Use ◽  
Diuretic Activity ◽  
First Line ◽  
Potassium Homeostasis ◽  
Diuretic Drugs ◽  
Pharmacological Target ◽  
Diuretic Agents ◽  
Effective Drugs

In the last four decades, the several classes of diuretics, currently available for clinical use, have been the first line option for the therapy of widespread cardiovascular and non-cardiovascular diseases. Diuretic drugs generally exhibit an overall favourable risk/benefit balance. However, they are not devoid of side effects. In particular, all the classes of diuretics cause alteration of potassium homeostasis. <p> In recent years, understanding of the physiological role of the renal outer medullary potassium (ROMK) channels, has shown an intriguing pharmacological target for developing an innovative class of diuretic agents: the ROMK inhibitors. This novel class is expected to promote diuretic activity comparable to (or even higher than) that provided by the most effective drugs used in clinics (such as furosemide), with limited effects on potassium homeostasis. <p> In this review, the physio-pharmacological roles of ROMK channels in the renal function are reported, along with the most representative molecules which have been currently developed as ROMK inhibitors.

scholarly journals Caspase-14—From Biomolecular Basics to Clinical Approach. A Review of Available Data

2021 ◽  
Vol 22 (11) ◽  
pp. 5575
Author(s):  
Agnieszka Markiewicz ◽  
Dawid Sigorski ◽  
Mateusz Markiewicz ◽  
Agnieszka Owczarczyk-Saczonek ◽  
Waldemar Placek
Keyword(s):  
Cell Death ◽  
Physiological Role ◽  
Skin Barrier ◽  
Clinical Aspects ◽  
Clinical Approach ◽  
Search Term ◽  
Caspase Family ◽  
Skin Conditions ◽  
Theoretical Science

Caspase-14 is a unique member of the caspase family—a family of molecules participating in apoptosis. However, it does not affect this process but regulates another form of programmed cell death—cornification, which is characteristic of the epidermis. Therefore, it plays a crucial role in the formation of the skin barrier. The cell death cycle has been a subject of interest for researchers for decades, so a lot of research has been done to expand the understanding of caspase-14, its role in cell homeostasis and processes affecting its expression and activation. Conversely, it is also an interesting target for clinical researchers searching for its role in the physiology of healthy individuals and its pathophysiology in particular diseases. A summary was done in 2008 by Denecker et al., concentrating mostly on the biotechnological aspects of the molecule and its physiological role. However, a lot of new data have been reported, and some more practical and clinical research has been conducted since then. The majority of studies tackled the issue of clinical data presenting the role of caspase in the etiopathology of many diseases such as retinal dysfunctions, multiple malignancies, and skin conditions. This review summarizes the available knowledge on the molecular and, more interestingly, the clinical aspects of caspase-14. It also presents how theoretical science may pave the way for medical research. Methods: The authors analyzed publications available on PubMed until 21 March 2021, using the search term “caspase 14”.

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