Immunogold–silver staining of extracellular ligninases secreted by Phanerochaete chrysosporium

1991 ◽  
Vol 37 (9) ◽  
pp. 665-668 ◽  
Author(s):  
Richard Lackner ◽  
Ewald Srebotnik ◽  
Kurt Messner

The secretion of ligninases by Phanerochaete chrysosporium was investigated with polyclonal antibodies, followed by immunogold–silver staining and light microscopy. After growing fungal mycelium on nitrocellulose, extracellular ligninases were detected around old, plasmaless hyphae, but not at arthrospores, chlamydospores, or blastoconidia. Labeling of fungal hyphae on cover-slip cultures was observed only when the cell wall was highly porous and translocation of cell material occurred. These experiments suggested that there is a correlation between hyphal lysis and the release of extracellular ligninases from hyphae. Key words: ligninase secretion, immunogold–silver staining, Phanerochaete chrysosporium.

2009 ◽  
Vol 69 (2) ◽  
pp. 263-269 ◽  
Author(s):  
LT. Maranho ◽  
M. Dziedzic ◽  
GIB. Muñiz ◽  
YS. Kuniyoshi ◽  
F. Galvão

Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) is native and a member of the Pinophyta (Gymnosperm) of southern Brazil, locally known as "pinheiro-bravo". The present work aims to investigate the effects of petroleum on the tracheids dimensions. Wood samples from twenty individuals were studied along the stem, ten being exposed to pollution and ten used as a control set. The wood samples were collected from incisions at three levels: at the ground level, and one and two metres above the ground level. From these samples, sub-samples were selected at the border of the growth layers in the vascular cambium-medulla direction. The methodology followed that traditionally recommended for plant anatomy studies, with analyses done by light microscopy (OLYMPUS - BX41) assisted by the software Image Pro-plus for measurements. Comparison of the individuals exposed to petroleum with the control set, showed that the length, diameter and cell wall width of the tracheids of the former were smaller, a trend which was statistically significant according to the Student's t-test. These traits were observed mainly on the tracheids of the last growth layer, corresponding to the year in which the individuals were exposed to petroleum.


1998 ◽  
Vol 78 (4) ◽  
pp. 719-722
Author(s):  
A. D. Iwaasa ◽  
K. A. Beauchemin ◽  
S. N. Acharya ◽  
J. G. Buchanan-Smith

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents


1997 ◽  
Vol 75 (5) ◽  
pp. 762-768 ◽  
Author(s):  
Masatoshi Saikawa ◽  
Masami Oguchi ◽  
Rafael F. Castañeda Ruiz

Infection of nematodes by Meristacrum asterospermum and Zygnemomyces echinulatus was initiated by conidia adhering to the nematode's cuticle. Each conidium developed an infection peg to penetrate the nematode after adhesion. In M. asterospermum, an infection peg just under the penetration was found in ultrathin sections, in which the peg's cell wall was broken into several lobes that were covered entirely with an amorphous mass of electron-opaque substance. Septa formed in the apical portion of aerial conidiophore under conidiation. The septal wall was nonperforate and often contained electron-opaque inclusions. Vegetative hyphae of Z. echinulatus had typical bifurcate septa, but septa at both ends of the pedicel of conidia were often slightly deformed. Key words: infection of nematodes, Meristacrum asterospermum, septum, Zygnemomyces echinulatus.


1994 ◽  
Vol 72 (10) ◽  
pp. 1489-1495 ◽  
Author(s):  
X. XuHan ◽  
A. A. M. Van Lammeren

Microtubular cytoskeletons in nuclear, alveolar, and cellular endosperm of bean (Phaseolus vulgaris) were analyzed immunocytochemically and by electron microscopy to reveal their function during cellularization. Nuclear endosperm showed a fine network of microtubules between the wide-spaced nuclei observed towards the chalazal pole. Near the embryo, where nuclei were densely packed, bundles of microtubules radiated from nuclei. They were formed just before alveolus formation and functioned in spacing nuclei and in forming internuclear, phragmoplast-like structures that gave rise to nonmitosis-related cell plates. During alveolus formation cell plates extended and fused with other newly formed walls, thus forming the walls of alveoli. Growing wall edges of cell plates exhibited arrays of microtubules perpendicular to the plane of the wall, initially. When two growing walls were about to fuse, microtubules of both walls interacted, and because of the interaction of microtubules, the cell walls changed their position. When a growing wall was about to fuse with an already existing wall, such interactions between microtubules were not observed. It is therefore concluded that interactions of microtubules of fusing walls influence shape and position of walls. Thus microtubules control the dynamics of cell wall positioning and initial cell shaping. Key words: cell wall, cellularization, endosperm, microtubule, Phaseolus vulgaris.


1999 ◽  
Vol 12 (10) ◽  
pp. 862-871 ◽  
Author(s):  
Pascal Laurent ◽  
Catherine Voiblet ◽  
Denis Tagu ◽  
Dulcinéia de Carvalho ◽  
Uwe Nehls ◽  
...  

Development of the ectomycorrhizal symbiosis leads to the aggregation of fungal hyphae to form the mantle. To identify cell surface proteins involved in this developmental step, changes in the biosynthesis of fungal cell wall proteins were examined in Eucalyptus globulus-Pisolithus tinctorius ectomycorrhizas by two-dimensional polyacrylamide gel electrophoresis. Enhanced synthesis of several immunologically related fungal 31- and 32-kDa polypeptides, so-called symbiosis-regulated acidic polypeptides (SRAPs), was observed. Peptide sequences of SRAP32d were obtained after trypsin digestion. These peptides were found in the predicted sequence of six closely related fungal cDNAs coding for ectomycorrhiza up-regulated transcripts. The PtSRAP32 cDNAs represented about 10% of the differentially expressed cDNAs in ectomycorrhiza and are predicted to encode alanine-rich proteins of 28.2 kDa. There are no sequence homologies between SRAPs and previously identified proteins, but they contain the Arg-Gly-Asp (RGD) motif found in cell-adhesion proteins. SRAPs were observed on the hyphal surface by immunoelectron microscopy. They were also found in the host cell wall when P. tinctorius attached to the root surface. RNA blot analysis showed that the steady-state level of PtSRAP32 transcripts exhibited a drastic up-regulation when fungal hyphae form the mantle. These results suggest that SRAPs may form part of a cell-cell adhesion system needed for aggregation of hyphae in ectomycorrhizas.


1984 ◽  
Vol 133 (1) ◽  
pp. 99-102 ◽  
Author(s):  
José Fernandez-Piqueras ◽  
Carlos Sentis Castaño ◽  
E. Rojo Garcia ◽  
A. Rodriguez Campos

1995 ◽  
Vol 73 (6) ◽  
pp. 862-866 ◽  
Author(s):  
Carla D. Zelmer ◽  
R. S. Currah

Corallorhiza trifida Châtelain, or pale coral root orchid, is a heterotrophic, leafless, rootless, terrestrial orchid with a circumboreal distribution. Because of its relative inability to photosynthesize, the orchid obtains energy through the digestion of fungal hyphae that grow within the cells of its contorted, yellowish, coralloid rhizomes. Recently, we isolated and cultured strains of a slow-growing basidiomycete with bright yellow, clamped hyphae that are typical of the fungal cells present in C. trifida endomycorrhizas from different treed habitats at widely distributed locations in the northern hemisphere. By inoculating the roots of Pinus contorta Douglas ex Loudon seedlings with this fungus we were able to demonstrate its ability to form distinctive ectomycorrhizas with an ectotrophic, woody plant. The formation of endomycorrhizas with C. trifida and ectomycorrhizas with P. contorta indicates that in nature a triple symbiosis, with a circumboreal distribution, exists among certain trees, the coral root orchid, and this yellow basidiomycete that links the two and functions as a mycorrhizal symbiont in both. Key words: Corallorhiza trifida, orchid mycorrhiza, triple symbiosis, ectomycorrhiza, Pinus contorta.


2011 ◽  
Vol 24 (6) ◽  
pp. 421 ◽  
Author(s):  
Ann Bohte ◽  
Andrew N. Drinnan

Developmental anatomy of eucalypt flower buds from flower to mature fruits was investigated using light microscopy. Several important features contribute to the maturity of flower and fruit. The epidermis of the flower in many species is replaced by periderm in the fruit. Brachysclereid idioblasts develop in the parenchymatous zone beneath the epidermis; fibres develop from cambium-like activity in the vascular bundles located in the mid-region of the ovary wall; and cells adjacent to the locule lining mature as transversely oriented filiform sclereids. The initiation of these features in relation to anthesis varies among taxa, and this influences flower and fruit anatomy and morphology. In taxa where sclereids and fibres are initiated following anthesis, there is substantial post-anthesis growth and fruits are larger than flowers. When these features are developed before anthesis, the flowers are essentially pre-fruits that exhibit little or no further growth in the fruit stage apart from additional cell-wall lignification. Several other anatomical features, such as oil ducts and the distribution of oil glands and crystal layers, are not developmentally variable, but are phylogenetically informative within the eucalypt group.


2000 ◽  
Vol 79 (5) ◽  
pp. 2382-2390 ◽  
Author(s):  
Salomon Bartnicki-Garcia ◽  
Charles E. Bracker ◽  
Gerhard Gierz ◽  
Rosamaría López-Franco ◽  
Haisheng Lu

2004 ◽  
Vol 82 (8) ◽  
pp. 1074-1088 ◽  
Author(s):  
R. Larry Peterson ◽  
Hugues B Massicotte

The roots or other subterranean organs of most plants develop symbioses, mycorrhizas, with fungal symbionts. Historically, mycorrhizas have been placed into seven categories based primarily on structural characteristics. A new category has been proposed for symbiotic associations of some leafy liverworts. An important feature of mycorrhizas is the interface involved in nutrient exchange between the symbionts. With the exception of ectomycorrhizas, in which fungal hyphae remain external to plant cell walls, all mycorrhizas are characterized by fungal hyphae breaching cell walls but remaining separated from the cell cytoplasm by a plant-derived membrane and an interfacial matrix that forms an apoplastic compartment. The chemical composition of the interfacial matrix varies in complexity. In arbuscular mycorrhizas (both Arum-type and Paris-type), molecules typical of plant primary cell walls (i.e., cellulose, pectins, β-1,3-glucans, hydroxyproline-rich glycoproteins) are present. In ericoid mycorrhizas, only rhamnogalacturonans occur in the interfacial matrix surrounding intracellular hyphal complexes. The matrix around intracellular hyphal complexes in orchid mycorrhizas lacks plant cell wall compounds until hyphae begin to senesce, then molecules similar to those found in primary cell walls are deposited. The interfacial matrix has not been studied in arbutoid mycorrhizas and ectendomycorrhizas. In ectomycorrhizas, the apoplastic interface consists of plant cell wall and fungal cell wall; alterations in these may enhance nutrient transfer. In all mycorrhizas, nutrients must pass into the symplast of both partners at some point, and therefore current research is exploring the nature of the opposing membranes, particularly in relation to phosphorus and sugar transporters.Key words: interface, apoplastic compartment, Hartig net, arbuscule, intracellular complex, nutrient exchange.


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