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.

Structure and development of Pinus banksiana – Wilcoxina ectendomycorrhizae

1991 ◽  
Vol 69 (10) ◽  
pp. 2135-2148 ◽  
Author(s):  
Pamela F. Scales ◽  
R. L. Peterson
Keyword(s):  
Electron Microscopy ◽  
Pinus Banksiana ◽  
Cortical Cell ◽  
Root Surface ◽  
Cell Plasma Membrane ◽  
Cortical Cells ◽  
Hartig Net ◽  
Transmission Electron ◽  
Cell Plasma ◽  
Wilcoxina Mikolae

Seedlings of Pinus banksiana were grown in growth pouches and inoculated with Wilcoxina mikolae var. mikolae, Wilcoxina mikolae var. tetraspora, and Wilcoxina rehmii. Ectendomycorrhizae formed between P. banksiana and W. mikolae var. mikolae developed rapidly following inoculation. The mantle was of variable width, and a large amount of mucigel was evident on the root surface. Intracellular penetration of the cortical cells by hyphae occurred one to two cells distal to Hartig net formation. Both light and transmission electron microscopy revealed labyrinthic growth of Hartig net hyphae that were densely cytoplasmic during early penetration stages but became vacuolate as the association aged. Intracellular colonization of the cortex was extensive, with the hyphae highly branched and surrounded by an interfacial matrix and cortical cell plasma membrane. The external morphology and anatomy of ectendomycorrhizae formed between W. mikolae var. tetraspora and W. rehmii and P. banksiana were similar to those described for W. mikolae var. mikolae. Key words: ectendomycorrhizae, Wilcoxina, Pinus banksiana, intracellular, Hartig net, E-strain.

scholarly journals Chemical and Structural Changes in White Sauces Thawed by Microwave or Conventional Oven

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S290-S292
Author(s):  
L. M Guardeño ◽  
E. Llorca ◽  
I. Pérez-Munuera ◽  
A. Quiles ◽  
I. Hernando
Keyword(s):  
Soluble Protein ◽  
Protein Fraction ◽  
Structural Changes ◽  
Lipid Fraction ◽  
Confocal Scanning Laser Microscopy ◽  
Fat Globules ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Total Crude Protein ◽  
Conventional Oven

Proteins, lipids and structural changes in white sauces after being stored at –18°C and thawed by microwave and conventional oven were studied in this work. The total crude and soluble protein fractions were quantified by N-Kjeldahl. The acidity grade and oxidation spectrophotometric parameters (k<sub>232</sub> and k <sub>270</sub>) were used to analyse the lipid fraction. In addition, confocal scanning laser microscopy (CSLM) was used to study the structure of the sauce. The results showed that the total crude protein fraction increased in the thawed samples if compared to the freshly-prepared samples, mainly when microwave oven was used. However, the soluble protein fraction did not vary significantly (<I>P</I> < 0.05) among the different samples. Regarding the lipid changes, the acidity index did not show significant differences among the samples. K<sub>232</sub> values of the microwave-thawed samples differed significantly from the freshly-prepared and the conventional-thawed samples. Furthermore, k<sub>270</sub> values were significantly different between the samples thawed using the conventional oven and the freshly-prepared ones. CSLM images showed degradation of the starch granules and an increase of size in the fat globules due to thawing.

Differences in the colonization of Pinus banksiana roots by sib-monokaryotic and dikaryotic strains of ectomycorrhizal Laccaria bicolor

1989 ◽  
Vol 67 (6) ◽  
pp. 1717-1726 ◽  
Author(s):  
Ken K. Y. Wong ◽  
Yves Piché ◽  
Diane Montpetit ◽  
Bradley R. Kropp
Keyword(s):  
Pinus Banksiana ◽  
Intraspecific Variability ◽  
Root Cell ◽  
Laccaria Bicolor ◽  
Cortical Cells ◽  
Aseptic Culture ◽  
Hartig Net ◽  
Cell Layers ◽  
The Mean ◽  
Root Surfaces

First-order laterals of Pinus banksiana seedlings were inoculated with variant strains of ectomycorrhizal Laccaria bicolor in an aseptic culture system. Macroscopic observations of 10 fungal strains indicated that 6 are mycorrhizal and 4 are apparently nonmycorrhizal. Furthermore, light microscopic examinations revealed significant intraspecific variation in mycorrhizal structures. The mean mantle thickness, mean mantle density, and mean Hartig net penetration of the six mycorrhizal strains ranged from 2.5 to 13.4 hyphae, 278 to 411 hyphae/mm and 2 to 2.8 root cell layers, respectively. Three of these strains formed fewer macroscopically observable mycorrhizae and developed significantly thinner mantles but their Hartig nets usually separated cortical cells more extensively. Three of the four apparently nonmycorrhizal strains showed infrequent and poor Hartig net development (mean penetration of 0.3 to 0.8 root cell layer), poor surface colonization, and no mantle development. These three strains were better able to colonize long roots. Only one strain could be considered truly nonmycorrhizal because it only colonized root surfaces poorly and never showed mantle or Hartig net formation. The observed intraspecific variability raises questions concerning the determinants of mycorrhiza development and structure.

Ontogeny of Alnus rubra – Alpova diplophloeus ectomycorrhizae. I. Light microscopy and scanning electron microscopy

1989 ◽  
Vol 67 (1) ◽  
pp. 191-200 ◽  
Author(s):  
H. B. Massicotte ◽  
R. L. Peterson ◽  
L. H. Melville
Keyword(s):  
Outer Layer ◽  
Lateral Root ◽  
Lateral Roots ◽  
Root Hairs ◽  
Fungal Colonization ◽  
Alnus Rubra ◽  
Cortical Cells ◽  
Lateral Root Primordia ◽  
Hartig Net ◽  
Fungal Hyphae

Ectomycorrhizae synthesized between Alpova diplophloeus and Alnus rubra are of two morphological types: one with a mantle formed along the entire length of the lateral roots and the other, the clavate type, with the mantle confined to the apical portion of the laterals. The morphology of the mycorrhiza is dependent on the stage of lateral root elongation at the time of colonization by fungal hyphae. Clavate mycorrhizae form on lateral roots that have already elongated at the time of fungal colonization. Fungal hyphae interact with root hairs at the base of clavate mycorrhizae. Mantles of both types are fairly compact with few extramatrical hyphae. Hartig net hyphae, which branch profusely primarily in the radial direction, are confined to the epidermis and midway along the radial walls of the outer layer of cortical cells. Second-order lateral root primordia are initiated in the mature Hartig net zone. Cells in the outer layer of the cortex of mycorrhizal roots collapse during fixation, indicating the possible presence of a barrier in the cell wall blocking the ingress of fixative.

The cholinergic, serotoninergic and peptidergic components of the nervous system of Moniezia expansa (Cestoda, Cyclophyllidea)

Parasitology ◽  
1993 ◽  
Vol 106 (4) ◽  
pp. 429-440 ◽  
Author(s):  
A. G. Maule ◽  
D. W. Halton ◽  
C. Shaw ◽  
C. F. Johnston
Keyword(s):  
Nervous System ◽  
Chemical Elements ◽  
Close Association ◽  
Confocal Scanning Laser Microscopy ◽  
Neurokinin A ◽  
Nerve Fibres ◽  
C Terminus ◽  
Confocal Scanning ◽  
Moniezia Expansa ◽  
Confocal Scanning Laser

SUMMARYThe central (CNS) and peripheral (PNS) nervous systems of the cyclophyllidean tapeworm, Moniezia expansa, were examined for the presence of cholinergic, serotoninergic and peptidergic elements using enzyme cytochemical and immunocytochemical techniques in conjunction with light and confocal scanning laser microscopy. Cholinesterase activity and 5-hydroxytryptamine- and regulatory peptide-immunoreactivities (IRs) were localized to the nerve fibres and cell bodies of all of the major neuronal components in the CNS of the worm, including the cerebral ganglia and connecting commissure, the 10 longitudinal nerve cords and associated transverse ring commissures. Although each of the 3 systems appeared well developed and comprised a significant portion of the nervous system, the serotoninergic constituent was the most highly developed, consisting of a vast array of nerve fibres and cell bodies distributed throughout the strobila of the worm. A close association of cholinesterase reactivity and peptide-IRs was evident throughout the CNS, indicating the possible co-localization of acetylcholine and neuropeptides. Within the PNS, cholinergic activity and serotoninergic- and peptidergic-IRs occurred in the subtegumental network of nerve fibres and somatic musculature. Although all 3 neuro-chemical elements were present in the acetabula, they were found in different nerve fibres; only cholinergic and peptidergic cell bodies were found. The common genital opening, vagina and ootype regions of the reproductive system displayed a rich innervation of all 3 types of neuronal populations. Within the peptidergic system, immunostaining with antiseraraised to the C-terminus of the neuropeptide Y superfamily of peptides and the invertebrate peptides, neuropeptide F (M. expansa) and FMRFamide was the most prevalent. Limited positive-IR for substance P and neurokinin A were also recorded in the CNS of the worm.

A structural study of the interaction between the ectomycorrhizal fungus Pisolithus tinctorius and Pinus strobus roots

1983 ◽  
Vol 61 (4) ◽  
pp. 1185-1193 ◽  
Author(s):  
Y. Piché ◽  
R. L. Peterson ◽  
Melanie J. Howarth ◽  
J. André Fortin
Keyword(s):  
Light And Electron Microscopy ◽  
Cortical Cell ◽  
Middle Lamella ◽  
Pinus Strobus ◽  
Ectomycorrhizal Fungus ◽  
Pisolithus Tinctorius ◽  
Cortical Cells ◽  
Root Cells ◽  
Hartig Net ◽  
Limited Digestion

Stages in ectomycorrhizal development between the fungus Pisolithus tinctorius (Pers.) Coker & Couch and short roots of Pinus strobus L. were followed in growth pouches. Short roots from preinoculation through Hartig net formation were processed for light and electron microscopy. Fungal hyphae approaching the surface of roots have Thiéry-positive substances in their modified walls and in lomasomes, indicating the possibility of extracellular polysaccharide secretion. Hyphae grow between and beneath the flattened, tannin-filled superficial root cells and subsequently into the intercellular region of the cortex. A Hartig net several hyphae wide is formed, isolating the cortical cells from each other. Plasmodesmata were not observed in these cortical cells. Middle lamella material is always present around the intercellular hyphae, suggesting limited digestion by the hyphae. Cortical cell cytoplasm becomes necrotic in regions of mature Hartig net formation.

Computer-Assisted Analysis of Multi-Color Confocal Microscopic Datasets: Automated Light Microscopic Discrimination of Synaptic Relationships

1996 ◽  
Vol 54 ◽  
pp. 284-285
Author(s):  
M Wessendorf ◽  
A Beuning ◽  
D Cameron ◽  
J Williams ◽  
C Knox
Keyword(s):  
Nerve Fibers ◽  
Confocal Scanning Laser Microscopy ◽  
Computer Assisted ◽  
Nerve Terminals ◽  
Neuronal Somata ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Entire Cell ◽  
Confocal Scanning Laser ◽  
Assisted Analysis

Multi-color confocal scanning-laser microscopy (CSLM) allows examination of the relationships between neuronal somata and the nerve fibers surrounding them at sub-micron resolution in x,y, and z. Given these properties, it should be possible to use multi-color CSLM to identify relationships that might be synapses and eliminate those that are clearly too distant to be synapses. In previous studies of this type, pairs of images (e.g., red and green images for tissue stained with rhodamine and fluorescein) have been merged and examined for nerve terminals that appose a stained cell (see, for instance, Mason et al.). The above method suffers from two disadvantages, though. First, although it is possible to recognize appositions in which the varicosity abuts the cell in the x or y axes, it is more difficult to recognize them if the apposition is oriented at all in the z-axis—e.g., if the varicosity lies above or below the neuron rather than next to it. Second, using this method to identify potential appositions over an entire cell is time-consuming and tedious.

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