Isolation of Oidiodendron maius from Rhododendron and ultrastructural characterization of synthesized mycorrhizas

1989 ◽  
Vol 67 (7) ◽  
pp. 2206-2212 ◽  
Author(s):  
G. C. Douglas ◽  
M. C. Heslin ◽  
C. Reid
Keyword(s):  
Close Association ◽  
Calluna Vulgaris ◽  
Interfacial Zone ◽  
Root Cells ◽  
Ultrastructural Characterization ◽  
Mycorrhizal Roots ◽  
Oidiodendron Maius ◽  
Alternative Sources ◽  
Aseptic Conditions ◽  
Host Nucleus

Twelve fungal isolates were obtained from roots of field-grown Rhododendron plants. One of these produced ericoid mycorrhizal roots within 5 days when reassociated with Rhododendron plantlets under aseptic conditions. The organism was identified as Oidiodendron maius. A characteristic feature of this organism was production of conidiophores in both pure culture and in association with root cells of the host. Ultrastructural observations confirmed its mycorrhizal status and showed intracellular hyphae surrounded by an interfacial zone and plasma membrane. Hyphae were found in close association with the host nucleus and cytoplasmic organelles. Pure isolates derived from diverse alternative sources were also tested for mycorrhizal formation with Rhododendron under aseptic conditions. Thus, Pezizella ericae obtained from Calluna vulgaris produced mycorrhizal infections after 10 days of culture, whereas O. maius from Sitka spruce and Oidiodendron griseum from wood pulp failed to form mycorrhizas.

Host microtubules in the Hartig net region of ectomycorrhizas, ectendomycorrhizas, and monotropoid mycorrhizas

2004 ◽  
Vol 82 (7) ◽  
pp. 938-946 ◽  
Author(s):  
Yukari Kuga-Uetake ◽  
Melissa Purich ◽  
Hugues B Massicotte ◽  
R. Larry Peterson
Keyword(s):  
Pinus Banksiana ◽  
Structural Changes ◽  
Close Association ◽  
Confocal Scanning Laser Microscopy ◽  
Fungal Colonization ◽  
Cortical Cells ◽  
Root Cells ◽  
Hartig Net ◽  
Confocal Scanning Laser ◽  
Wilcoxina Mikolae

Various categories of mycorrhizas are recognized primarily by the structural changes that occur between fungi and roots. In all mycorrhiza categories, cytological modifications of root cells accompany the establishment of the functional symbiosis, and among these are alterations in the organization of the cytoskeleton. Using immuno labelling combined with confocal scanning laser microscopy, this study documents changes in microtubules (MTs) in root cells of ectendomycorrhizas and monotropoid mycorrhizas; in addition, ectomycorrhizas were reinvestigated to determine the effect of fungal colonization on host root cells. In Pinus banksiana L. – Laccaria bicolor (Maire) Orton ectomycorrhizas, MTs were present in epidermal and cortical cells adjacent to the Hartig net. The remaining cortical MTs had a different organization when compared with those of cortical cells of control roots. MTs were present in Hartig net hyphae. In ectendomycorrhizas formed when roots of P. banksiana were colonized by the ascomycete, Wilcoxina mikolae var. mikolae Yang & Korf, MTs were present adjacent to intracellular hyphae and host nuclei, but few cortical MTs were present. MTs were present within Hartig net and intracellular hyphae. In field-collected roots of Monotropa uniflora L., MTs were associated with fungal pegs, intracellular extensions of inner mantle hyphae within epidermal cells. The close association between MTs and fungal pegs may be related to the formation of the highly branched host-derived wall that envelops each fungal peg. The development of exchange interfaces in the three systems studied involve changes in the organization of microtubules.Key words: cytoskeleton, microtubules, Hartig net, mycorrhizas, immunolocalization, confocal microscopy.

scholarly journals Active metabolites of the genus Piper against Aedes aegypti: natural alternative sources for dengue vector control

2014 ◽  
Vol 20 (1) ◽  
pp. 61 ◽  
Author(s):  
Andre Marques ◽  
Maria Auxiliadora C. Kaplan
Keyword(s):  
Aedes Aegypti ◽  
Close Association ◽  
Active Metabolites ◽  
Principal Vector ◽  
Tropical Regions ◽  
Hemorrhagic Fevers ◽  
Development Cycle ◽  
Vector Management ◽  
Pure Compounds ◽  
Alternative Sources

The mosquito, Aedes aegypti;, is the principal vector of the viruses responsible for dengue and dengue hemorrhagic fevers. The mosquito is widespread throughout tropical and sub-tropical regions; its prevalence makes dengue one of the most important mosquito-borne viral diseases in the world occurring annually in more than 100 endemic countries. Because blood is essential to their development cycle, the Aedes species maintains a close association with humans and their dwellings. Fittingly, the most widely adopted strategy to decrease the incidence of these diseases is the control of the mosquito larvae population. The emergence of insecticide-resistant mosquitoes has amplified the interest in finding natural products effective against Aedes aegypti; adults, as well as larvae. Plant-derived compounds have played an important role in the discovery of new active entities for vector management as they are safer and have lower toxicity to humans in comparison to conventional insecticides. This review assesses a naturally occurring plant matrix and pure compounds of the Piper species, which have been shown to be active against Aedes aegypti;.

scholarly journals Transcription of a Gene Encoding a Lectinlike Glycoprotein Is Induced in Root Cells Harboring Arbuscular Mycorrhizal Fungi in Pisum sativum

1999 ◽  
Vol 12 (9) ◽  
pp. 785-791 ◽  
Author(s):  
Raffaella Balestrini ◽  
Silvia Perotto ◽  
Elena Gasverde ◽  
Preeti Dahiya ◽  
Lise-Lotte Guldmann ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Mycorrhizal Fungi ◽  
Root Nodules ◽  
Arbuscular Mycorrhizal ◽  
Pcr Primers ◽  
Root Cells ◽  
Hybridization Probes ◽  
Mycorrhizal Roots ◽  
Pea Roots

The gene PsNlec1, which encodes a lectinlike glycoprotein, is strongly expressed in pea nodule tissue. Using gene-specific polymerase chain reaction (PCR) primers, in situ hybridization probes, and specific antisera derived from the PsNlec1 sequence, we investigated gene expression associated with the arbuscular mycorrhizal (AM) symbiosis of pea roots. With the use of reverse transcription (RT)-PCR and cold in situ hybridization, strong expression of the transcript was demonstrated not only in root nodules but also in mycorrhizal roots when the cells were colonized by the endomycorrhizal fungus Glomus versiforme. No transcript was detectable in uninfected pea roots. With an antiserum raised against PsNLEC-1 polypeptide, a single antigenic band (25 kDa) was observed following gel electrophoresis of extracts from mycorrhizal roots. However, the amount of antigen was apparently too low to be detected by immunogold localization in tissue sections of pea mycorrhizal roots.

Study on phosphorus metabolism in growing sheep fed different sources of calcium by using the isotope dilution technique

2003 ◽  
Vol 2003 ◽  
pp. 194-194
Author(s):  
R. S. Dias ◽  
A. P. Roque ◽  
V. F. Nascimento ◽  
L. A. Castilho ◽  
M. R. S. R. Peçanha ◽  
...  
Keyword(s):  
Isotope Dilution ◽  
Close Association ◽  
Animal Nutrition ◽  
Phosphorus Metabolism ◽  
Dilution Technique ◽  
Isotope Dilution Technique ◽  
Lack Of Information ◽  
Alternative Sources ◽  
Different Sources

The close association of calcium and phosphorus in bone, and the narrow relationship between these minerals makes this subject always an important aim of study for researches on animal nutrition (Braithwaite, 1984). The utilization of alternative sources of calcium has been studied in Brazil in the last years however there is a lack of information about the effects of these sources on phosphorus metabolism. The aim of this study was to evaluate phosphorus metabolism in sheep fed four different sources of calcium through determination of true absorption and endogenous faecal loss of phosphorus by using the isotope dilution technique (Vitti et al., 2000).

Immunocytochemical Localization of Amyloid Protein AA in the “Dense Fibrillar Inclusions” of the Reticuloendothelical Cells

1977 ◽  
Vol 35 ◽  
pp. 438-439
Author(s):  
T. Shirahama ◽  
M. Skinner ◽  
A.S. Cohen
Keyword(s):  
Amyloid Fibril ◽  
Close Association ◽  
Gel Filtration ◽  
Fibril Formation ◽  
Amyloid Protein ◽  
Electron Microscopic ◽  
Amyloid Deposits ◽  
Amyloid Fibril Formation ◽  
Electron Microscopic Technique ◽  
Lysosomal System

A1thought the mechanisms of amyloidogenesis have not been entirely clarified, proteolysis of the parent proteins may be one of the important steps in the amyloid fibril formation. Recently, we reported that "dense fibrillar inclusions" (DFI), which had the characteristics of lysosomes and contained organized fibrillar profiles as well, were observed in the reticuloendothelial cells in close association with the foci of new amyloid deposits. We considered the findings as evidence for the involvement of lysosomal system in amyloid fibril formation (l). In the present study, we attempted to determine the identity of the contents of the DFI by the use of antisera against the amyloid protein (AA) and an immuno-electron microscopic technique.Amyloidosis was induced in CBA/J mice by daily injections of casein (l). AA was isolated from amyloid-laden spleens by gel filtration and antibody to it was produced in rabbits (2). For immunocytochemistry, the unlabeled antibody enzyme method (3) was employed.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

Linear Arrays of Helical Polyribosomes in Cells Exposed to Antitumor Drug Vincristine Sulfate

1969 ◽  
Vol 27 ◽  
pp. 358-359
Author(s):  
Awtar Krishan
Keyword(s):  
Close Association ◽  
Annulate Lamellae ◽  
Large Array ◽  
Vincristine Sulfate ◽  
Linear Arrays ◽  
Golgi Membranes ◽  
Related Drug ◽  
Drug Leads ◽  
Lethal Doses ◽  
Vinblastine Sulfate

Earle's L-929 fibroblasts treated with mitosis-arresting but sub-lethal doses of vinblastine sulfate (VLB) show hypertrophy of the granular endoplasmic reticulum and annulate lamellae. Exposure of the cells to heavier doses of vincristine sulfate (VCR), a VLB-related drug, leads to the accumulation of large amounts of helical polyribosomes, Golgi membranes and crystals in the cytoplasm. In many of these cells a large number of helical polyribosomes are arranged in prominent linear rows, some of which may be up to 5 micrometers in length. Figure 1 shows a large array of helical polyribosomes near a crystalline mass (CRS) in an Earle's L-929 fibroblast exposed to VCR (5ϒ/ml.) for 3 hours At a higher magnification, as seen in figure 2, the helical polyribosomes are seen arranged in parallel rows. In favorably cut sections, a prominent backbone like "stalk" of finely granular material, measuring approximately 300Å in width is seen in close association with the linear rows of helical polyribosomes.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

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