Ultrastructural localization of carbohydrate in cell walls of the entomogenous hyphomycete Nomuraea rileyi

1992 ◽  
Vol 38 (5) ◽  
pp. 377-386 ◽  
Author(s):  
J. C. Pendland ◽  
D. G. Boucias
Keyword(s):  
Cell Walls ◽  
Ultrastructural Localization ◽  
Outer Wall ◽  
Nomuraea Rileyi ◽  
Larval Hemolymph ◽  
Gold Conjugate ◽  
Hyphal Bodies ◽  
Hyphal Body ◽  
Host Parasite ◽  
Germ Tubes

Several probes were used in this ultrastructural study to localize polysaccharides in cell walls on conidial germ tubes, hyphal bodies, and mycelia of the entomogenous hyphomycete Nomuraea rileyi. With the exception of galactose, labelling patterns did not vary from one morphological stage to another. Galactose, which was localized by using a monoclonal antibody to a galactose-specific lectin purified from insect larval hemolymph, was absent from cell walls of hyphal bodies and conidia but was present on germ-tube and mycelial surfaces. Chitin (N-acetylglucosamine), labelled with a wheat-germ agglutinin-ferritin conjugate, was present in the middle regions of lateral walls and septa, and β1-4 glucans were located in the middle and inner regions, as indicated by binding of a cellulase-gold conjugate. An anti-laminaribiose antibody was used to label β1-3 glucans present in the outer wall areas and inner regions near the plasmalemma. The location of mannose residues as indicated by concanavalin A - ferritin binding was similar to that of the β1-3 glucans; vesicle-like structures were also labelled. None of the probes labelled the outer conidial pellicle or exocellular sheath surrounding germ tubes, and labelling of mycelial sheath was inconsistent. The absence of galactose from Nomuraea hyphal body walls is discussed in terms of host-parasite interaction. Key words: Nomuraea rileyi, entomopathogenic fungi, glycoconjugates, lectins, monoclonal antibodies.

scholarly journals Processes in the Infection of Barley Leaves by Rhynchosporium Secalis

1970 ◽  
Vol 23 (2) ◽  
pp. 300 ◽  
Author(s):  
EN AYESU-OFFEI ◽  
BG CLARE
Keyword(s):  
Epidermal Cell ◽  
Cell Walls ◽  
Rhynchosporium Secalis ◽  
Barley Leaves ◽  
Germ Tubes

Conidia of R. secalis (Oud.) Davis germinated on barley leaves to produoe , short germ tubes and appressoria. Hyphae below the appressoria penetrated the outicle and formed extensive myoelial mats between the cuticle and the outer epidermal cell walls. Epidermal cell walls beneath the subcuticular hyphae became swollen, lamellate, and collapsed so that the inner and outer walls of the epidermis came together.

Ultrastructural changes in the cell surface of Coelomomyces punctatus infecting mosquito larvae

1976 ◽  
Vol 54 (13) ◽  
pp. 1419-1437 ◽  
Author(s):  
Martha J. Powell
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Granular Material ◽  
Fat Body ◽  
Vegetative Stage ◽  
Ultrastructural Changes ◽  
Anopheles Quadrimaculatus ◽  
Advanced Stages ◽  
Hyphal Bodies ◽  
Hyphal Body

As the fungus Coelomomyces punctatus develops in the coelomic cavity of the mosquito Anopheles quadrimaculatus, the conformation of the plasma membrane and extracellular coat of the fungus changes markedly. The vegetative stage was surrounded by a granular and fibrillar extracellular coat which reacted positively in the silver methenamine procedure for the localization of polysaccharides. Numerous simple, branched or contorted cytoplasmic protuberances covered the irregularly shaped hyphal bodies. The surface of the hyphal body adjacent to the fat body of the mosquito had occasional involutions of the plasma membrane sheathed by cisternae of endoplasmic reticulum. In contrast with these hyphal bodies, cytoplasmic protuberances were spaced at wide intervals along filamentous hyphae. Aborting thalli were contorted and deeply lobed. The plasma membrane was smooth, and cytoplasmic protuberances were absent on other hyphae and hyphal bodies, particularly at advanced stages of infection. Instead unattached vesicles, morphologically similar to the protuberances found on some thalli, were embedded in granular material clustered around the smooth plasma membrane of these thalli. Mosquito hemocytes appeared to engulf these vesicles and granular material. As the vegetative stage was transformed into the reproductive stage, a newly formed, compact extracellular layer surrounded the sporangial initial. Later, a darkly staining wall appeared around the resting sporangium. Cisternae of endoplasmic reticulum consistently subtended thin areas in this pitted wall.

Distribution of Autofluorescence and Esterase and Peroxidase Activities in the Epidermis of Wheat Roots

1979 ◽  
Vol 6 (2) ◽  
pp. 201 ◽  
Author(s):  
MM Smith ◽  
TP O'brien
Keyword(s):  
Cell Walls ◽  
Outer Wall ◽  
Wheat Root ◽  
Root Cell ◽  
Gaeumannomyces Graminis ◽  
Wall Material ◽  
Wheat Roots ◽  
Pig Liver Esterase ◽  
Auto Fluorescence ◽  
Root Cell Walls

In the wheat root, peroxidases and esterases specific for a-naphthyl esters of acetate, propionate and butyrate are concentrated in cell walls, particularly the outer wall of epidermal cells undergoing extension. In contrast esterases specific for β-naphthyl esters of propionate and butyrate were intra- cellular and concentrated in epidermal and outer root-cap cells of the wheat root. Both α-naphthyl and β-naphthyl esters of longer-chain fatty acids proved to be poor substrates. The esterases and peroxidases associated with the outer epidermal wall may well be involved in turnover of phenolic acids cross-linked to polysaccharides. In this regard, ferulic acid and diferulate were shown to be constituents of wheat-root cell walls. The distribution of these substances can also be inferred from autofluorescence. Treatment with a commercial pig-liver esterase was without effect on the auto- fluorescence of the root cell-walls. Culture filtrates from Gaeumannomyces graminis did remove significant amounts of autofluorescent wall material. These preparations contained α-naphthyl acetate esterase as well as many polysaccharide hydrolase activities.

Ascospore germination, growth in culture, and imperfect spore formation in Cookeina sulcipes and Phillipsia crispata

1975 ◽  
Vol 53 (1) ◽  
pp. 56-61 ◽  
Author(s):  
J. W. Paden
Keyword(s):  
Germ Tube ◽  
Outer Wall ◽  
Wall Layer ◽  
Spore Formation ◽  
Spore Surface ◽  
No Formation ◽  
Ascospore Germination ◽  
Germ Tubes

Ascospores of Cookeina sulcipes germinate by one of two modes: (1) by the production of blastoconidia on sympodially proliferating conidiogenous cells which may arise from any point on the spore surface, and (2) by a thick polar germ tube. No ascospores were seen to germinate both ways. The conidiogenous cells are occasionally modified into narrow hyphae. The blastoconidia germinate readily but are evidently very short-lived. Ascospores of Phillipsia crispata germinate by two polar germ tubes; there is no formation of blastoconidia. In both species the inner ascospore wall separated from an outer wall layer during germination. In culture both C. sulcipes and P. crispata form arthroconidia. The arthroconidia are uninucleate; they germinate readily and reproduce the species when transferred to fresh plates.

Wilts caused by Verticillium species. A cytological survey of vascular alterations in leaves

1982 ◽  
Vol 60 (6) ◽  
pp. 825-837 ◽  
Author(s):  
Jane Robb ◽  
Alexandra Smith ◽  
Lloyd Busch
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Sem Analysis ◽  
Disease Symptoms ◽  
Vascular Tissues ◽  
Transmission Electron ◽  
Tem Method ◽  
Cytological Alterations ◽  
Host Parasite ◽  
Leaf Symptoms

Plants that are infected with fungi of the species Verticillium frequently develop foliar disease symptoms which may include one or more of the following: flaccidity, drying, chlorosis leading to necrosis, vascular browning, epinasty, and leaf abscission. A number of ultrastructural and chemical alterations occur in the vascular tissues of such leaves: deposition of brown pigments, coating of xylem vessel walls with abnormal material (i.e., lipid-rich coatings or fibrillar coatings), plugging of xylem vessels with gums, gels or tyloses, degeneration of parenchyma cells, and accumulation of abnormal electron dense materials in primary and secondary cell walls. Different host–parasite combinations exhibit different leaf symptoms and different cytological alterations. The purpose of the present survey was to determine whether the extent of any of the possible vascular alterations in leaves could be correlated with the wilting tendency of the host.Chrysanthemums, snapdragons, eggplants, sunflowers, potatoes, sycamore maples and hedge maples were infected with V. dahliae; alfalfa and hops were infected with V. albo-atrum. When leaf symptoms were well advanced, samples were taken from the major lateral leaf veins and were prepared for light (LM) and transmission electron microscopy (TEM) or scanning electron microscopy (SEM). The various types of alterations in the vascular tissues were identified by a correlated LM–TEM method and (or) SEM analysis and for each sample vein the proportion of vessels affected by each type of alteration was calculated. Four leaf samples, each from different plants, were analysed for each host. The visual symptoms, including vascular browning, were estimated subjectively. The degree of leaf flaccidity was correlated positively with the proportion of lipid-coated vessels and inversely with the degree of vascular browning. No other correlations were observed.

An inexpensive medium for mass fermentation production of Entomophaga aulicae hyphal bodies competent to form conidia

1993 ◽  
Vol 39 (6) ◽  
pp. 588-593 ◽  
Author(s):  
Richard A. Nolan
Keyword(s):  
Growth Medium ◽  
Entomopathogenic Fungus ◽  
Basal Medium ◽  
Fermentation Medium ◽  
Eastern Hemlock ◽  
Developmental Sequence ◽  
Hyphal Bodies ◽  
Hyphal Body ◽  
Hemlock Looper ◽  
Single Medium

A mass fermentation medium for growth and morphogenesis of the entomopathogenic fungus Entomophaga aulicae was developed. This fungus is a major pathogen of larval eastern hemlock looper and spruce budworm. The medium consists of a basal medium plus 0.8% tryptic soy broth and 0.4% calcium caseinate. This medium is a major breakthrough in that (i) the E. aulicae developmental sequence from protoplast inoculum to hyphal bodies competent to form conidia can be carried out in a single medium without adjustment, (ii) by examining the fermentation product it can be determined if conidia can be produced prior to engaging in costly field spraying, (iii) this medium supports the growth of E. aulicae isolates from different geographical areas, (iv) the medium is relatively inexpensive, (v) the hyphal bodies are easily separated from the spent growth medium, and (vi) the hyphal body yield is high.Key words: Entomophaga aulicae, mass fermentation medium, hyphal bodies, conidia, insect biocontrol.

Ultrastructural localization of succinate dehydrogenase in a self-parasitic isolate of Saprolegnia megasperma

1977 ◽  
Vol 23 (5) ◽  
pp. 491-496
Author(s):  
Sharon Faye Murrin ◽  
Richard A. Nolan
Keyword(s):  
Electron Microscopy ◽  
Succinate Dehydrogenase ◽  
Cell Walls ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Mitochondrial Membranes ◽  
Hyphal Cell ◽  
Dense Deposits

The enzyme succinate dehydrogenase (SDH, succinate: (acceptor) oxidoreductase, EC 1.3.99.1) was localized by the combined techniques of cytochemistry and electron microscopy in the hyphae of a self-parasitizing isolate of Saprolegnia megasperma Coker. The enzyme was localized in the mitochondrial membranes; its activity was inhibited by malonate. Electron-dense deposits, whose formation was not prevented by the addition of malonate, appeared outside of the hyphal cell walls. No evidence was found at the ultrastructural level within the vegetative hyphae for any abnormalities which could be linked to the phenomenon of self-parasitism.

Physiological studies with the fungus Entomophaga aulicae during morphogenesis in three different media under fermentation conditions

1993 ◽  
Vol 39 (7) ◽  
pp. 701-708
Author(s):  
Richard A. Nolan
Keyword(s):  
Amino Acid ◽  
Serum Albumin ◽  
Glucose Utilization ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Basal Medium ◽  
Fermentation Conditions ◽  
Hyphal Bodies ◽  
Hyphal Body ◽  
Body Production

The effects of three different media on amino acid uptake and production and glucose and oxygen utilization during protoplast growth and hyphal body production by the fungus Entomophaga aulicae under fermentation conditions were studied. The three media consisted of a basal medium plus either (i) 2.8% fetal calf serum, (ii) 0.8% tryptic soy broth plus 0.4% bovine serum albumin, or (iii) 0.8% tryptic soy broth plus 0.4% calcium caseinate. The protoplasts grew most rapidly (initial peaks on days 2 and 3) and hyphal bodies were detected first (day 3) in the media containing albumin and caseinate. The day 9 hyphal body yields were 3.1 × 107, 7.5 × 108, and 3.1 × 109/10 L in media containing the serum, albumin, and caseinate, respectively. Growth in the albumin and caseinate media also gave the first detectable glucose utilization (days 2 and 3, respectively) and this rapidly increased to 94.9 and 90.6% utilization, respectively, on day 4. Oxygen and glucose utilization were closely related. During protoplast growth prior to hyphal body production, the only common pattern detected was the initial utilization of glutamine in serum- and caseinate-containing media. During the initial period of hyphal body production, cysteic acid, threonine, serine, asparagine, leucine, tyrosine, phenylalanine, and arginine were first utilized and glycine, alanine, and ammonia were first produced in the albumin and caseinate media. At this time (days 3–5), glutamine, proline, cystine, and tryptophan were first utilized and valine and histidine were produced in the albumin medium, and methionine was first utilized and cystathionine produced in the caseinate medium. Four main patterns of overall amino acid utilization and production were identified. The delay in major protoplast growth in the basal medium plus fetal calf serum is felt to result from inhibition by free fatty acids in the serum. Protein utilization was not detected and its main function is considered to be enhancement of protoplast stability against fermentation shear forces.Key words: Entomophaga aulicae, physiology, fermentation growth, protoplasts, hyphal bodies.

Étude en microscopie électronique de Conidiobolus obscurus. I. Formation et germination des azygospores

1982 ◽  
Vol 60 (4) ◽  
pp. 413-431 ◽  
Author(s):  
J. P. Latgé ◽  
M. C. Prévost ◽  
D. F. Perry ◽  
O. Reisinger
Keyword(s):  
Metabolic Pathways ◽  
Spore Wall ◽  
Wall Layer ◽  
Lipid Globule ◽  
Large Numbers ◽  
Microscopie Électronique ◽  
Hyphal Bodies ◽  
Hyphal Body ◽  
Reserve Lipid ◽  
Dormant Spore

The multinucleate hyphal bodies of Conidiobolus obscurus are characterized by a striated wall which does not react with Thiéry's stain used to detect free α glycol groups. In the developing mycelial zone, the protoplasm contains microvesicles and electron-dense corpuscles; during ageing of the mycelium, lipid globules varying in size according to the age of the cell and vesicles with dense inclusions are observed in large numbers, whereas the endoplasmic reticulum shows little development. The onset of sporulation is characterized by protoplasmic condensation at a particular point in the hyphal body through successive accumulations of cicatricial partitions. The young prespore is a spherical organ; its wall has the same structure as that of the mycelium, and it contains more or less the same organelles as the hyphal protoplasm. The first sign that the prespore is developing into a spore is the deposition of a very thick inner wall layer (tripartite layer). The inner makeup of the azygospore has all the features of a dormant spore of low metabolic activity having a huge reserve lipid globule. At the onset of germination, the spore wall and the central lipid globule are progressively digested. A new wall entity is synthesized. There is a proliferation of multivesicular and multilaminate bodies. The emergence of the germ tube results from the rupture of the original outer layer of the spore. Results are compared with those observed in various resistance organs of zygomycetes and oomycetes, and discussed in relation to functional metabolic pathways during sporogenesis or germination. [Journal translation]

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