A simple test to detect sulphur deficiency in wheat

1982 ◽  
Vol 33 (3) ◽  
pp. 443 ◽  
Author(s):  
R Moss ◽  
PJ Randall ◽  
CW Wrigley
Keyword(s):  
Phosphate Buffer ◽  
Colour Change ◽  
Simple Test ◽  
Wheat Grain ◽  
Colour Intensity ◽  
Breadmaking Quality ◽  
Sulphur Deficiency ◽  
Highly Correlated ◽  
Low Sulfur ◽  
Colour Classes

Wheat grain from sulfur-adequate plants remains straw yellow in colour when soaked in glutaraldehyde, but grain from sulfur-deficient plants turns brown or purplish brown. This observation is the basis of a proposed test to identify low-sulfur grain samples, and thus to identify sites requiring sulfur fertilizer. The colour formed during treatment with 4% glutaraldehyde in pH 6.8 phosphate buffer is ranked zero (no colour change), 1, 2 or 3 (maximum colour intensity). A glutaraldehyde score is then awarded on the basis of the percentage of grains in each of these four colour classes. Scores range from 0 to 300 with sulfur-deficient samples having scores > 100. The glutaraldehyde score was highly correlated with N/S ratio in the grain (v = 0.88***) and negatively correlated with percentage sulfur in the grain (r = -0.60** *). In a program to identify wheat-grain samples which are deficient in sulfur for breadmaking quality or yield, the glutaraldehyde test could be used in preliminary sorting to identify those samples requiring further testing.

Sulfur and nitrogen fertilizer effects on wheat. II. Influence on grain quality

1981 ◽  
Vol 32 (2) ◽  
pp. 213 ◽  
Author(s):  
HJ Moss ◽  
CW Wrigley ◽  
R MacRichie ◽  
PJ Randall
Keyword(s):  
Grain Quality ◽  
Nitrogen Concentration ◽  
High Mobility ◽  
Nitrogen Supply ◽  
Small Scale ◽  
Dough Quality ◽  
Wide Range ◽  
Highly Correlated ◽  
Nitrogen Treatments ◽  
Low Sulfur

A wide range of grain quality tests (on both a large and a small scale) was performed on samples obtained from a factorial (5 sulfur x 3 nitrogen treatments) field experiment in which Olympic wheat responded in yield of grain to both sulfur and nitrogen. Grain nitrogen concentration responded mainly to nitrogen supply and ranged from 1.38 to 2.56%. Grain sulfur concentration responded to both sulfur and nitrogen supply and varied from 0.08 to 0.18%. Flour sulfur was highly correlated with, but lower than, grain sulfur. Compared with high sulfur grain, low sulfur grain was harder (higher pearling resistance) and the dough had a greater resistance to extension and a lower extensibility. In fact, a restricted supply of sulfur seriously affected grain quality, producing a dough that was excessively tough and umuitable for normal use. These changes in dough quality were accompanied by decreases in the proportions of albumins and of high mobility gliadins in the total protein in the low sulfur grain.

scholarly journals The Sulphur Response in Wheat Grain and Its Implications for Acrylamide Formation and Food Safety

2020 ◽  
Vol 21 (11) ◽  
pp. 3876 ◽  
Author(s):  
Sarah Raffan ◽  
Joseph Oddy ◽  
Nigel G. Halford
Keyword(s):  
Food Safety ◽  
Genetic Control ◽  
Nitrogen Availability ◽  
Regulatory Protein ◽  
Regulatory Compliance ◽  
Asparagine Synthetase ◽  
Human Consumption ◽  
Wheat Grain ◽  
Basic Leucine Zipper ◽  
Sulphur Deficiency

Free (soluble, non-protein) asparagine concentration can increase many-fold in wheat grain in response to sulphur deficiency. This exacerbates a major food safety and regulatory compliance problem for the food industry because free asparagine may be converted to the carcinogenic contaminant, acrylamide, during baking and processing. Here, we describe the predominant route for the conversion of asparagine to acrylamide in the Maillard reaction. The effect of sulphur deficiency and its interaction with nitrogen availability is reviewed, and we reiterate our advice that sulphur should be applied to wheat being grown for human consumption at a rate of 20 kg per hectare. We describe the genetic control of free asparagine accumulation, including genes that encode metabolic enzymes (asparagine synthetase, glutamine synthetase, glutamate synthetase, and asparaginase), regulatory protein kinases (sucrose nonfermenting-1 (SNF1)-related protein kinase-1 (SnRK1) and general control nonderepressible-2 (GCN2)), and basic leucine zipper (bZIP) transcription factors, and how this genetic control responds to sulphur, highlighting the importance of asparagine synthetase-2 (ASN2) expression in the embryo. We show that expression of glutamate-cysteine ligase is reduced in response to sulphur deficiency, probably compromising glutathione synthesis. Finally, we describe unexpected effects of sulphur deficiency on carbon metabolism in the endosperm, with large increases in expression of sucrose synthase-2 (SuSy2) and starch synthases.

Serological Methods and Selective Agars To Enumerate Campylobacter from Broiler Carcasses: Data from Inter- and Intralaboratory Analyses†

2004 ◽  
Vol 67 (5) ◽  
pp. 901-907 ◽  
Author(s):  
GREGORY R. SIRAGUSA ◽  
JOHN E. LINE ◽  
LEONARD L. BROOKS ◽  
TINA HUTCHINSON ◽  
JOEL D. LASTER ◽  
...  
Keyword(s):  
Phosphate Buffer ◽  
Latex Agglutination ◽  
Agglutination Test ◽  
Microscopic Technique ◽  
Test Format ◽  
Routine Procedure ◽  
Serological Tests ◽  
Sample Throughput ◽  
Confirmatory Tests ◽  
Highly Correlated

Routine analytical means to estimate Campylobacter numbers per milliliter of carcass rinses are needed in high-sample-throughput poultry laboratories. We compared three serological confirmatory tests that were amenable to such a setting when used in conjunction with Campy-Line and Campy-Cefex Campylobacter selective agars. Pre- and post-chlorinated chiller carcass rinse samples were obtained and held on ice, then analyzed 24 h later in two separate laboratories. Presumptive counts on both pre- and postchiller samples from between laboratories on individual agars and between both agars were highly correlated. Agreement among the three serological tests was nearly complete. The use of a premeasured and dried latex anti- Campylobacter antibody agglutination test format was superior to that of either a liquid latex agglutination format or a direct phosphate-buffer microscopic technique in terms of practicality as was the inclusion of an unarmed latex control to detect auto agglutination. A routine procedure for Campylobacter level estimation was suggested. This procedure, when used in conjunction with a serological confirmatory step, should provide processors with a means to assess reductions in numbers per milliliter of carcass rinses versus strictly presence-absence testing.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Visualization of Antibody Transport in Rat Visceral Yolk-Sac Placenta

1982 ◽  
Vol 40 ◽  
pp. 246-247
Author(s):  
William P. Jollie
Keyword(s):  
Phosphate Buffer ◽  
Yolk Sac ◽  
Female Rats ◽  
Thin Sections ◽  
Visceral Yolk Sac ◽  
Antibody Complex ◽  
Cytochemical Reaction ◽  
Hind Foot ◽  
Antigen Antibody ◽  
Yolk Sac Placenta

A technique has been developed for visualizing antibody against horseradish peroxidase (HRP) in rat visceral yolk sac, the placental membrane across which passive immunity previously has been shown to be transferred from mother to young just prior to birth. Female rats were immunized by injecting both hind foot pads with 1 mg HRP emulsified in complete Freund's adjuvant. They were given a booster of 0.5mg HRP in 0.1 ml normal saline i.v. after one week, then bred and autopsied at selected stages of pregnancy, viz., 12, 1 7 and 22 days post coitum, receiving a second booster, injected as above, five days before autopsy. Yolk sacs were removed surgically and fixed immediately in 2% paraformaldehye, 1% glutaraldehye in 0.1 M phosphate buffer with 0.01% CaCl2 at pH 7.4, room temperature, for 3 hr, rinsed 3X in 0.1 M phosphate buffer plus 5% sucrose, then exposed to 1 mg HRP in 1 ml 0.1 M phosphate buffer at pH 7.4 for 1 hr. They were refixed in aldehydes, as above, for 1 5 min (to assure binding of antigen-antibody complex). Following buffer washes, the tissues were incubated in 3 mg diaminobenzidine tetrahydrochloride and 0.01% H2O2 in 0.05 M Tris-HCl buffer for 30 min. After brief buffer washes, they were postfixed in 2% OsO4. in phosphate buffer at pH 7.4, 4°C for 2 hr, dehydrated through a graded series of ethanols, and embedded in Durcupan. Thin sections were observed and photographed without contrast-enhancement with heavy metals. Cytochemical reaction product marked the site of HRP (i.e., antigen) which, in turn, was present only where it was bound with anti-HRP antibody.

Ultrastructure of developing visual cortical synapses in the cat superior colliculus

1991 ◽  
Vol 49 ◽  
pp. 156-157
Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce
Keyword(s):  
Superior Colliculus ◽  
Phosphate Buffer ◽  
Receptive Fields ◽  
Visual Cortical Area ◽  
Cortical Synapses ◽  
Visual Cortical ◽  
And Function ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Cat Superior Colliculus

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.

Resolution of Channels in the Exine by Translocation of Colloidal Iron

1971 ◽  
Vol 29 ◽  
pp. 352-353
Author(s):  
John R. Rowley
Keyword(s):  
Phosphate Buffer ◽  
Pollen Development ◽  
Osmium Tetroxide ◽  
Pollen Grains ◽  
Deionized Water ◽  
Colloidal Iron ◽  
Fixed Material ◽  
Epilobium Angustifolium ◽  
Untreated Material ◽  
Microspore Mitosis

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

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