Glycosyltransferases in plant and animal tissues effects of fixation and lead on enzyme activity.

1978 ◽  
Vol 26 (10) ◽  
pp. 772-781 ◽  
Author(s):  
W D Klohs ◽  
C W Goff ◽  
R J Bernacki
Keyword(s):  
Enzyme Activity ◽  
Lead Nitrate ◽  
Initial Step ◽  
Lead Ions ◽  
Fixation Time ◽  
Animal Tissues ◽  
Root Tips ◽  
Cytochemical Localization ◽  
Onion Root ◽  
L1210 Cells

As the initial step toward the cytochemical localization of glycosyl-transferases in situ, biochemical determinations of these enzyme activities from onion root tips and L1210 cells were performed before and after fixation as well as in the presence of lead ions. Glycosyltransferase activity from roots fixed in buffered formaldehyde or glutaraldehyde before homogenization decreased as the concentration of the fixative or fixation time was increased. Formaldehyde fixation was less inhibitory than glutaraldehyde; 35% of the glycosyltransferase activity was retained after 30 min fixation in 2% formaldehyde while 25% of the enzyme activity remained after a similar fixation in glutaraldehyde. Substantially higher levels of L1210 cell glycosyltransferase activity were retained after a 30 min 2% formaldehyde fixation (60% sialyltransferase; 82% galactosyltransferase), but inhibition by glutaraldehyde was similar to that observed for onion root galactosyltransferase. Glycosyltransferase from formaldehyde-fixed roots was inhbited 35% by lead nitrate, but sialytransferase from formaldehyde-fixed L1210 cells was unaffected by lead ions. These findings are encouraging for further studies aimed at the development of cytochemical technique to localize glycosyltransferase in plant and animal tissues.

A CHARACTERIZATION OF NUCLEOSIDE DIPHOSPHATASE IN THE ONION ROOT TIP

1973 ◽  
Vol 21 (5) ◽  
pp. 417-425 ◽  
Author(s):  
W. D. KLOHS ◽  
C. W. GOFF
Keyword(s):  
Enzyme Activity ◽  
Lead Nitrate ◽  
Maximal Activity ◽  
Root Tip ◽  
Uridine Diphosphate ◽  
Onion Root ◽  
Guanosine Diphosphate ◽  
Inosine Diphosphatase ◽  
Triton X ◽  
Nucleoside Diphosphatase

Inosine diphosphatase of a Golgi-enriched fraction of the onion root tip was characterized. Peak enzyme activity occurred at pH 4.8 and 7.0, although considerable activity was present between the peaks. The activity at neutral pH approximately doubled during a 4-day cold storage; no such increase of the pH 4.8 activity occurred under similar conditions. Treatment with deoxycholate or Triton X-l00 also activated the pH 7.0 enzyme. Although magnesium, manganese and calcium all supported inosine diphosphatase activity, 2 mM manganese supported maximal activity. Uridine diphosphate, guanosine diphosphate and inosine diphosphate were hydrolyzed much more rapidly than the other substrates tested. Sodium fluoride, uranyl nitrate, potassium chloride and heat all partially inhibited the enzyme. Glutaraldehyde and lead nitrate, two reagents to which nucleoside diphosphatase is exposed when studied cytochemically, greatly reduced enzyme activity.

scholarly journals NUCLEOSIDE DIPHOSPHATASE IN THE ONION ROOT TIP I. EFFECTS OF FIXATION AND LEAD ON ENZYME ACTIVITY

1974 ◽  
Vol 22 (10) ◽  
pp. 945-951 ◽  
Author(s):  
C. W. GOFF ◽  
W. D. KLOHS
Keyword(s):  
Enzyme Activity ◽  
Root Tip ◽  
Fixation Time ◽  
Onion Root ◽  
Nucleoside Diphosphatase

The terminal 0.2—0.5 mm of 3-day onion roots grown from bulbs were excised and fixed for 1½ hr in various concentrations of cacodylate-buffered glutaraldehyde, formaldehyde or combinations of these. Alternatively, the fixative concentration was held constant while fixation time was varied. Control roots were run in buffer lacking fixative. The roots were then homogenized and in most cases aliquots of the entire homogenate were used to assay for total nucleoside diphosphatase (NDPase). Parallel assays were usually run after treating the homogenate with deoxycholate. Both glutaraldehyde and formaldehyde inhibited NDPase activity, the extent of this inhibition depending upon fixation time, fixative concentration and the particular aldehyde used, although with both fixatives inhibition did not increase beyond a certain level even with further increase in fixation time or fixative concentration. With glutaraldehyde and glutaraldehyde-containing fixatives, this level was normally about 74% inhibition while with formaldehyde it was about the level of non-activated NDPase activity and inhibition could be detected only after deoxycholate treatment. Lead did not appear to inhibit the "fixed" NDPase.

scholarly journals THE CYTOCHEMICAL LOCALIZATION OF ASCORBIC ACID IN ROOT TIP CELLS

1956 ◽  
Vol 2 (1) ◽  
pp. 87-92 ◽  
Author(s):  
William A. Jensen ◽  
Leroy G. Kavaljian
Keyword(s):  
Ascorbic Acid ◽  
Cell Surface ◽  
Silver Nitrate ◽  
Ribonucleic Acid ◽  
Root Tip ◽  
Root Tips ◽  
Cytochemical Localization ◽  
Meristematic Cells ◽  
Tip Cells ◽  
Root Tip Cells

The intracellular distribution of ascorbic acid was studied in frozen-dried root tips of Allium cepa and Vicia faba by the silver nitrate procedure. The sites of the ascorbic acid as indicated by the deposited silver appear as spherical (0.2 to 0.6 µ in diameter) cytoplasmic particles. The site appears to have small amounts of lipides and to be rich in ribonucleic acid. These particles are concluded to be submicroscopic in size and associated, in the elongating cell, with the cell surface. In the meristematic cells they appear fewer in number and are distributed throughout the cytoplasm.

Cellular Respiration in Onion Root Tips

1959 ◽  
Vol 120 (3) ◽  
pp. 131-137 ◽  
Author(s):  
W. E. Norris, ◽  
E. J. Harber ◽  
J. E. Butler
Keyword(s):  
Cellular Respiration ◽  
Root Tips ◽  
Onion Root

scholarly journals THE USE OF BISMUTH AS AN ELECTRON STAIN FOR NUCLEIC ACIDS

1963 ◽  
Vol 17 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Peter Albersheim ◽  
Ursula Killias
Keyword(s):  
Nucleic Acids ◽  
Inorganic Phosphate ◽  
In Vitro Experiments ◽  
Root Tips ◽  
Onion Root ◽  
Cell Structures ◽  
Dividing Cells ◽  
Chromatin Material

Evidence is presented to show that bismuth combines in vitro with the phosphate of nucleic acids in a manner similar to its reaction with inorganic phosphate. When tested under similar conditions, protein exhibited no attraction for bismuth. The results of the in vitro experiments, which are of interest within themselves, may be indirectly applicable to in vivo staining. Dividing cells of onion root tips were fixed in OsO4, stained with bismuth, and examined in the electron microscope. The electron opacity of cell structures known to contain nucleic acids was enhanced by bismuth, while organelles known to lack appreciable quantities of DNA or RNA showed little, if any, change. Bismuth is particularly effective as a stain for the chromatin material during interphase and for the chromosomes during division.

Cytokinins and nuclear RNA levels in onion root tips

Planta ◽  
1972 ◽  
Vol 108 (4) ◽  
pp. 363-368 ◽  
Author(s):  
Nathalie Chaly ◽  
George Setterfield
Keyword(s):  
Root Tips ◽  
Onion Root ◽  
Nuclear Rna ◽  
Rna Levels

scholarly journals Ultrastructural demonstration of cytochrome oxidase via cytochrome C in cerebral cortex.

1979 ◽  
Vol 27 (9) ◽  
pp. 1261-1266 ◽  
Author(s):  
S Y Al-Ali ◽  
N Robinson
Keyword(s):  
Enzyme Activity ◽  
Cerebral Cortex ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Staining Pattern ◽  
Oxidative Polymerization ◽  
Intermembrane Space ◽  
Vascular Perfusion ◽  
Cytochemical Localization ◽  
Perfusion Fixation

A procedure for the ultrastructural cytochemical localization of cytochrome oxidase via cytochrome c in the cerebral cortex is described. Vascular perfusion fixation by formaldehyde and glutaraldehyde of different concentrations and mixtures of the two gave varying results. A mixture of 4% formaldehyde and 0.5% glutaraldehyde gave the best combination of ultrastructural preservation and retention of enzyme activity. Histochemical methods were examined for optimum incubation conditions, based on the oxidative polymerization of 3,3'-diaminobenzidine (DAB) to an osmiophilic product. The reaction product was discretely localized within intercristate and the intermembrane space of mitochondria. The staining pattern was the same in nerve cells and in neuroglia and their processed. The DAB reaction product was also found in mitochondria of the endothelial cells.

scholarly journals Toxic and mutagenic activities of surface water from the Chumysh River

2017 ◽  
Vol 7 (2) ◽  
pp. 104-109
Author(s):  
L. P. Khlebova ◽  
N. N. Chernysheva ◽  
A. P. Kraynov
Keyword(s):  
River Water ◽  
Chromosomal Abnormalities ◽  
Mutagenic Activity ◽  
Tap Water ◽  
Control Sample ◽  
Test System ◽  
Root Tips ◽  
Allium Test ◽  
Temporal And Spatial Distribution ◽  
Onion Root

<p>The Allium test system is worldwide used for biological monitoring of environmental pollutants. We have studied toxic and mutagenic activity of water from the Chumysh River, which is one of the largest tributaries of the Upper Ob. Water samples were taken near industrial settlement Talmenka (Altai Territory of Russia) during the spring flood and low autumn water level in 2015. Root tips of <em>Allium cepa</em> L. was used as a biological model. There were examined 30 samples. Purified tap water of medium hardness served as a control sample. After the synchronizing the cell divisions, the onion bulbs with roots reaching a length of 2-3 mm were transferred to glass cups containing the selected samples of River water and cultured for several days at a temperature of +24 ± 1°C. After exposure, root tips were rinsed in distilled water and fixed in a cold mixture of ethanol and acetic acid (3:1). Fixed samples were used after 12-24 h or transferred to 70% alcohol and stored in refrigerator at a temperature of +4°C until required. The fixed materials were hydrolyzed in 1N HCl at 60°C for 5-8 min and squashed in aceto-orcein.<strong> </strong>Prepared slides were viewed under the microscope at a magnification of ×90.<strong> </strong>The mitotic index (MI), the phase indices, the frequency of abnormal mitosis, and chromosomal aberrations were determined by the examination of 500 cells per a replicate (100 cells per slide). We established that the decreased or increased levels of mitotic activity and the frequencies of pathological mitoses (up to 7.9%, P &lt; 0.05) in onion root tips revealed the presence of mitotoxic and genotoxic agents in the Chumysh River water. We found that the most number of chromosomal abnormalities occurs at the stages of meta- or anaphase. The main abnormalities are chromosome laggings in meta- and anaphase, chromosome bridges, chromosome fragments and micronuclei. Their number increased in 5.0-10.8 times compared with the control value. It has been discovered the temporal and spatial distribution of compounds with different toxicity and genotoxicity within a stream. The greatest level of mitotic depression and the highest frequency of chromosomal mutations were observed in the tissues of the onion root tips germinated on the samples collected in low autumn water. The mechanisms of plant adaptation to unfavorable environmental factors are discussed.</p>

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