Ultrastructural localization of polyphenoloxidase and peroxidase in roots and hypocotyls of cotton seedlings

1978 ◽  
Vol 56 (14) ◽  
pp. 1579-1587 ◽  
Author(s):  
W. C. Mueller ◽  
C. H. Beckman
Keyword(s):  
Cell Walls ◽  
Ultrastructural Localization ◽  
Endodermal Cell ◽  
Phenolic Metabolism ◽  
Enzyme Systems ◽  
In Cells

Polyphenoloxidase and peroxidase were localized and differentiated from each other in the roots and hypocotyls of cotton when these tissues were treated with dihydroxyphenylalanine (DOPA) and diaminobenizidine (DAB), respectively. The DOPA reaction occurred in the thylakoids of plastids from the endodermis of the root and in plastids from several tissues of the hypocotyl. The reaction was inhibited by diethyldithiocarbamate (DIECA), but catalase had no effect. An intense DAB reaction occurred in the epidermal, subepidermal, and endodermal cell walls of both roots and hypocotyls with a lesser reaction in the cortex and stele. DAB also caused a reaction in the microbodies in cells of all tissues, but a reaction could not be detected in other organelles. Aminotriazole (AT) inhibited the reaction in the microbodies but not in the cell walls, whereas the reaction was prevented entirely if H2O2 was eliminated from the medium. These results indicate that the two enzyme systems are localized in different and discrete areas in the cotton tissue and that the plastids are intimately involved in phenolic metabolism.

scholarly journals Comparative anatomy of the absorption roots of terrestrial and epiphytic orchids

2008 ◽  
Vol 51 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Ana Sílvia Franco Pinheiro Moreira ◽  
Rosy Mary dos Santos Isaias
Keyword(s):  
Cell Walls ◽  
Comparative Anatomy ◽  
Evolutionary Process ◽  
Minas Gerais ◽  
Point Of View ◽  
Endodermal Cell ◽  
Epiphytic Orchids ◽  
Anatomical Characteristics ◽  
Cell Layers ◽  
Casparian Strips

The present study compared roots of terrestrial and epiphytic Orchidaceae, analyzing the anatomical characteristics from an ecological point of view. The material was collected at three different sites in Minas Gerais / Brazil and was fixed in FAA. Transverse sections were obtained by freehand sections or from material previously embedded in Paraplast® or Historesin®. The prominent characteristics of the epiphytic group were: significant smaller perimeter, epidermis with 3 or more cell layers, U-thickened exodermal cell walls, O-thickened endodermal cell walls, and a low ratio between the caliber and the number of protoxylem arches. The terrestrial group presented simple or multiseriate epidermis, and exodermis and endodermis with typical Casparian strips. The anatomical characteristics should have evolved with several adaptations to distinct environments during evolutionary process.

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.

Biosynthesis of α-acetolactate and its conversion to diacetyl and acetoin in cell-free extracts of Lactobacillus casei

1972 ◽  
Vol 18 (4) ◽  
pp. 479-485 ◽  
Author(s):  
A. L. Branen ◽  
T. W. Keenan
Keyword(s):  
Lactobacillus Casei ◽  
Particulate Fraction ◽  
Thiamine Pyrophosphate ◽  
Optimal Activity ◽  
Enzyme Systems ◽  
Cells Cultured ◽  
In Cells

Cell-free extracts of Lactobacillus casei 393 required two enzyme systems for production of acetoin and diacetyl from pyruvate. An enzyme closely associated with the particulate fraction obtained after sonic oscillation produced α-acetolactate, required thiamine pyrophosphate and magnesium for optimal activity, and was inhibited by citrate. Acetolactate was converted to diacetyl and acetoin by both enzymatic and nonenzymatic processes. The enzyme responsible for conversion of acetolactate to diacetyl and acetoin was readily solubilized by sonication of cells. This enzyme required thiamine pyrophosphate or pyridoxalamine for optimal activity and its activity was enhanced in cells cultured in media containing citrate. Results obtained suggested that under conditions which exist in cultures, α-acetolactate was decarboxylated to diacetyl primarily by a nonenzymatic process.

Ultrastructural localization of sialylated glycoconjugates in cells of the salamander olfactory mucosa using lectin cytochemistry

1992 ◽  
Vol 267 (1) ◽  
pp. 113-124 ◽  
Author(s):  
James D. Foster ◽  
Marilyn L. Getchell ◽  
Thomas V. Getchell
Keyword(s):  
Ultrastructural Localization ◽  
Olfactory Mucosa ◽  
Lectin Cytochemistry ◽  
In Cells

scholarly journals Silicification of Root Tissues

Plants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 111 ◽  
Author(s):  
Alexander Lux ◽  
Zuzana Lukačová ◽  
Marek Vaculík ◽  
Renáta Švubová ◽  
Jana Kohanová ◽  
...  
Keyword(s):  
Plant Species ◽  
Cell Walls ◽  
Tissue Concentration ◽  
Essential Element ◽  
Essential Elements ◽  
Endodermal Cell ◽  
High Accumulation ◽  
Root Cells ◽  
Palm Species ◽  
Root Tissues

Silicon (Si) is not considered an essential element, however, its tissue concentration can exceed that of many essential elements in several evolutionary distant plant species. Roots take up Si using Si transporters and then translocate it to aboveground organs. In some plant species, root tissues are also places where a high accumulation of Si can be found. Three basic modes of Si deposition in roots have been identified so far: (1) impregnation of endodermal cell walls (e.g., in cereals, such as Triticum (wheat)); (2) formation of Si-aggregates associated with endodermal cell walls (in the Andropogoneae family, which includes Sorghum and Saccharum (sugarcane)); (3) formation of Si aggregates in “stegmata” cells, which form a sheath around sclerenchyma fibers e.g., in some palm species (Phoenix (date palm)). In addition to these three major and most studied modes of Si deposition in roots, there are also less-known locations, such as deposits in xylem cells and intercellular deposits. In our research, the ontogenesis of individual root cells that accumulate Si is discussed. The documented and expected roles of Si deposition in the root is outlined mostly as a reaction of plants to abiotic and biotic stresses.

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.

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