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.

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.

Vegetative interactions among mycelia of Laccaria bicolor in pure culture and in symbiosis with Pinus banksiana

1995 ◽  
Vol 73 (11) ◽  
pp. 1768-1779 ◽  
Author(s):  
Paul Y. de la Bastide ◽  
Yves Piché ◽  
Bradley R. Kropp
Keyword(s):  
Pure Culture ◽  
Pinus Banksiana ◽  
Dna Analysis ◽  
Agar Medium ◽  
Intraspecific Variability ◽  
Nuclear Migration ◽  
Laccaria Bicolor ◽  
Soil Medium ◽  
Mycelial Interactions ◽  
Ectomycorrhizal Colonization

Mycelial interactions of Laccaria bicolor strains were studied in pure culture and after inoculation onto mycorrhizal hosts. Monokaryon–monokaryon and dikaryon–monokaryon crosses were performed on an agar medium that enhanced nuclear migration to study mating events. The first observance of clamped hyphae, their location, evidence of nuclear migration, and the occurrence of dikaryon–monokaryon matings varied among crosses. One monokaryon–monokaryon and two dikaryon–monokaryon combinations were selected for seedling inoculation to compare their mycorrhizosphere interactions with those observed on agar medium. Seedlings of Pinus banksiana were grown for 20 weeks in a mycelium inoculated soil medium. Three seedlings from each treatment were selected at harvest and ectomycorrhizae reisolates were subject to randomly amplified polymorphic DNA analysis to identify genotypes. This analysis was also done for mycelial samples of the same crosses on agar medium. Variation in the mycobiont genotype was observed for different root isolates from the same seedling, which had been initially inoculated with a compatible monokaryon–monokaryon or a dikaryon–monokaryon strain combination. Root isolates from seedlings receiving the latter treatment included a new dikaryotic genotype produced by a dikaryon–monokaryon mating. Seedling growth was reduced with ectomycorrhizal colonization, most likely because of the photosynthate requirements of the mycobiont during this study. The nature of mycelial interactions and the potential value of a genetically variable mycobiont are discussed. Key words: Buller phenomenon, ectomycorrhizae, intraspecific variability, mycelial interactions, RAPD analysis.

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 The Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 Gene Is Involved in Anisotropic Root Growth during Osmotic Stress Adaptation

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 236
Author(s):  
María Belén Cuadrado-Pedetti ◽  
Inés Rauschert ◽  
María Martha Sainz ◽  
Vítor Amorim-Silva ◽  
Miguel Angel Botella ◽  
...  
Keyword(s):  
Osmotic Stress ◽  
Root Growth ◽  
Cell Walls ◽  
Primary Root ◽  
Stress Adaptation ◽  
Elongation Zone ◽  
Cortical Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Mean

Mutations in the Arabidopsis TETRATRICOPEPTIDE THIOREDOXIN-LIKE 1 (TTL1) gene cause reduced tolerance to osmotic stress evidenced by an arrest in root growth and root swelling, which makes it an interesting model to explore how root growth is controlled under stress conditions. We found that osmotic stress reduced the growth rate of the primary root by inhibiting the cell elongation in the elongation zone followed by a reduction in the number of cortical cells in the proximal meristem. We then studied the stiffness of epidermal cell walls in the root elongation zone of ttl1 mutants under osmotic stress using atomic force microscopy. In plants grown in control conditions, the mean apparent elastic modulus was 448% higher for live Col-0 cell walls than for ttl1 (88.1 ± 2.8 vs. 16.08 ± 6.9 kPa). Seven days of osmotic stress caused an increase in the stiffness in the cell wall of the cells from the elongation zone of 87% and 84% for Col-0 and ttl1, respectively. These findings suggest that TTL1 may play a role controlling cell expansion orientation during root growth, necessary for osmotic stress adaptation.

Structure and ontogeny of Betula alleghaniensis – Pisolithus tinctorius ectomycorrhizae

1990 ◽  
Vol 68 (3) ◽  
pp. 579-593 ◽  
Author(s):  
H. B. Massicotte ◽  
R. L. Peterson ◽  
C. A. Ackerley ◽  
L. H. Melville
Keyword(s):  
Root Hairs ◽  
Root Surface ◽  
Pisolithus Tinctorius ◽  
Initial Contact ◽  
Broad Host Range ◽  
Betula Alleghaniensis ◽  
Cortical Cells ◽  
Structural Modifications ◽  
Hartig Net ◽  
Primary Roots

The ontogeny and ultrastructure of ectomycorrhizae synthesized between Betula alleghaniensis (yellow birch) and Pisolithus tinctorius, a broad host range fungus, were studied to determine the structural modifications in both symbionts during ectomycorrhiza establishment. A number of stages, including initial contact of hyphae with the root surface, early mantle formation, and mature mantle formation, were distinguished. Interactions between hyphae and root hairs were frequent. As a paraepidermal Hartig net developed, root epidermal cells elongated in a radial direction, but wall ingrowths were not formed. Repeated branching of Hartig net hyphae resulted in extensive fine branches and the compartmentalization of hyphal cytoplasm. Nuclei and elongated mitochondria were frequently located in the narrow cytoplasmic compartments, and [Formula: see text] thickenings developed along walls of cortical cells in primary roots.

scholarly journals Anatomical investigations of the strawberry (Fragaria grandiflora Ehrh.) receptacle in the initial stages of development

2013 ◽  
Vol 34 (2) ◽  
pp. 195-207
Author(s):  
Jan Szymański
Keyword(s):  
Vascular Bundle ◽  
Apical Part ◽  
Strawberry Fruit ◽  
Cortical Cells ◽  
Anatomical Changes ◽  
Long Day ◽  
The Mean ◽  
Paraffin Method ◽  
Number Of Cells ◽  
Intensive Growth

The anatomical changes occurring in the strawberry fruit in the course of its growth were investigated. Flowers or fruits were collected from the apexes of the inflorescence of plants of the cultivar 'Talisman' cultivated in the glasshouse under long day. A method was developed for embedding the receptacle in a mixture of paraffin, rubber and wax, because the classical paraffin method did not give good results. Three different vascular bundle systems were distinguished in the strawberry, supplying the particular parts of the flower. Most intensive growth of the mean number of cells occurs in the cortex. The number of pith cells, beginning with the 5th day after pollination does not practically increase. Neither does between the 5th and 10th day after pollination, the number of cortical cells increase in the apical part of the fruit.

Evaluation of corallite size as a criterion for species discrimination in favositids

1988 ◽  
Vol 62 (1) ◽  
pp. 32-40 ◽  
Author(s):  
D. J. Lee ◽  
J. P. A. Noble
Keyword(s):  
Cross Section ◽  
Statistical Treatment ◽  
Intraspecific Variability ◽  
West Point ◽  
Species Discrimination ◽  
Cross Sectional ◽  
The Best Approximation ◽  
Computer Based ◽  
The Mean ◽  
Upper Silurian

Of all the morphologic characters used in favositid taxonomy, corallite size has most frequently been given more weight than others because of its relative ease of measurement and because it has been generally believed to be less variable. This study evaluates the reliability of corallite size as a criterion by a statistical treatment of several populations of favositids in the Upper Silurian West Point Reef Complex in Gaspé, Québec. Calculation of corallite cross-sectional area was made feasible by computer-based image analysis which provides a quick and accurate measure of size. The present study shows that the mean of the largest 10 percent corallite areas in mature parts of colonies with a minimum sample size of 100 corallites per cross section is the best approximation available of mean adult corallite size.It is suggested that intraspecific variability of corallite size is often too large for this character to be used in practice, probably due to phenotypic plasticity. The same may be true of most other morphologic characters. In some cases, however, one or two characters remain invariate within a species and can be used diagnostically. The same characters may be extremely variable in other species.

Cortical colonisation is not an absolute requirement for phosphorus transfer to plants in arbuscular mycorrhizas formed by Scutellospora calospora in a tomato mutant: evidence from physiology and gene expression

2010 ◽  
Vol 37 (12) ◽  
pp. 1132 ◽  
Author(s):  
Maria Manjarrez ◽  
Helle M. Christophersen ◽  
Sally E. Smith ◽  
F. Andrew Smith
Keyword(s):  
Gene Expression ◽  
Arbuscular Mycorrhizas ◽  
Physiological Data ◽  
Cortical Cells ◽  
Root Cells ◽  
Absolute Requirement ◽  
Cell Layers ◽  
Mycorrhizal Colonisation ◽  
Hyphal Coils ◽  
Scutellospora Calospora

Arbuscules in Arum-type arbuscular mycorrhizas (AM), formed intracellularly in root cortical cells, are generally believed to be the most important and defining characteristics of the symbiosis as sites for phosphorus (P) and carbon (C) exchange. We used a Pen + Coi– phenotype (penetration of epidermal and exodermal root cells but not arbuscule formation) formed in rmc (reduced mycorrhizal colonisation) mutant tomato (Lycopersicon esculentum Mill.) by Scutellospora calospora (Nicol. & Gerd.) Walker & Sanders to determine whether the fungus is capable of transferring P from soil to plant and whether there is concurrent upregulation of AM-inducible orthophosphate (Pi) transporter gene expression in the roots. Our physiological data showed that colonisation of outer root cell layers is sufficient for P transfer from S. calospora to tomato. This transfer of P was supported by increased expression of the Pi transporter genes, LePT3 and LePT5, known to be upregulated in AM interactions. We conclude that cortical colonisation and formation of arbuscules or arbusculate hyphal coils is not an absolute prerequisite for P transfer in this symbiosis.

Survey and ecological aspects of presumed ectomycorrhizal fungi associated with black spruce in northern Minnesota

1990 ◽  
Vol 68 (4) ◽  
pp. 825-831 ◽  
Author(s):  
Robert L. Doudrick ◽  
Elwin L. Stewart ◽  
Alvin A. Alm
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Picea Mariana ◽  
Selection Criteria ◽  
Black Spruce ◽  
Laccaria Bicolor ◽  
Site Preference ◽  
Geologic History ◽  
Aseptic Culture ◽  
Ecological Aspects ◽  
Spruce Stands

Twenty-two stands of black spruce, Picea mariana (Mill.) B.S.P., in northern Minnesota were surveyed for ectomycorrhizal fungi. Site selection criteria in black spruce stands included geologic history, soil type, stand origin, age, and productivity. Site preference relationships were noted for several of the 46 species of fungi collected during the 2-year study. Twenty-five isolates were tested in aseptic culture for their ability to form ectomycorrhizae with black spruce seedlings. Ectomycorrhizae were produced by Cenococcum sp., Laccaria bicolor (Maire) Orton, Laccaria laccata var. moelleri Singer, Rhizopogon sp., and Suillus cavipes (Opat.) Smith & Thiers.

A Petri dish technique for the aseptic synthesis of ectomycorrhizae

1989 ◽  
Vol 67 (6) ◽  
pp. 1713-1716 ◽  
Author(s):  
Ken K. Y. Wong ◽  
J. André Fortin
Keyword(s):  
Pinus Banksiana ◽  
Petri Dish ◽  
Microbial Interactions ◽  
Laccaria Bicolor ◽  
Larix Laricina ◽  
Hebeloma Cylindrosporum ◽  
First Order ◽  
Whole Plants ◽  
Improved Technique ◽  
Physiological And Biochemical

An improved technique was developed for the aseptic synthesis of ectomycorrhizae in Petri dishes. Within 2 weeks after inoculation of a first-order lateral, ectomycorrhizae were formed on Larix laricina and Pinus banksiana with Hebeloma cylindrosporum, Laccaria bicolor, and Pisolithus tinctorius. The technique should be useful for addressing physiological and biochemical questions concerning microbial interactions with roots of whole plants.

Sign in / Sign up

Export Citation Format

Share Document