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PubMed1988

Common features of three inversions in wheat chloroplast DNA.

We have determined the DNA sequences of regions involved in two of the three inversions known to have occurred during the evolution of wheat chloroplast DNA. This establishes the extent of the second largest of the three inversions. Examination of these sequences suggests that although short repeated sequences are present, the endpoints of the second and third inversions are not associated with repeated sequences as long as those associated with the first inversion. However the endpoints of all three inversions are all adjacent to at least one tRNA gene, and there is evidence that three of the tRNA genes have been subjected to partial duplication, possibly at the time of inversion. This suggests that tRNA genes might be involved with rearrangements of chloroplast DNA, as has also been postulated for mitochondrial DNA.

Base Sequence↗
PubMed1971

The role of peroxidase isozymes in resistance to wheat stem rust disease.

In common with other disease situations, rust-resistant wheat leaves show a large increase in peroxidase activity during infection. Peroxidase isozymes from healthy or infected lines of wheat (Triticum aestivum L.) near isogenic for resistance and susceptibility to race 56 of Puccinia graminis tritici were separated by gel electrophoresis and the activity of each was estimated by photometric scanning. In order to ensure that the activity of isozymes observed on gels reflected the changes found in peroxidase enzymes assayed spectrophotometrically in extracts, a study was made of extraction procedures, substrates, and reaction conditions for both types of enzyme measurements. Of the 14 isozymes detected in both healthy and infected leaves, increases in only 1 (isozyme 9) were associated consistently with the development of resistant disease reaction at 20 C. Additional evidence was obtained to show that this isozyme can account for the increased peroxidase activity observed in extracts from resistant plants. When plants with high induced peroxidase activity due to resistance at 20 C were treated with ethylene or transferred to 25 C, they reverted to complete susceptibility. However, the disease-induced activity of isozyme 9 did not fall. The data suggest that, in this case, the association of peroxidase with resistance was a consequence of, not a determinant in, resistance.

Journal Article↗
PubMed1975

Agglutination of leukemic and 2,4-dinitrophenyl-tagged normal human lymphocytes by wheat germ agglutinin.

The present study was undertaken to determine if leukemic and 2,4-dinitrophenyl (DNP)-tagged normal human lymphocytes shared common receptors for Wheat Germ Agglutinin (WGA), a lectin capable of reacting with malignant cells. Normal peripheral blood lymphocytes were tagged with 2,4-dinitrofluorobenzene (DNFB) at a ratio of 10-11 molecules/cell. Various concentrations of WGA were added to leukemic or tagged or untagged normal lymphocytes and incubated for 20 minutes at 37 degrees C, after which agglutination was scored visually. A readily discernible quantitative difference in the agglutinability of leukemic and DNP-tagged versus untagged normal cells was seen at all concentrations of WGA in the range of 50-800 mug/ml. The reaction was maximal when a ratio of 10-11 molecules of DNFB/cell was used for tagging and decreased progressively with 10-8, 10-6, 10-4, 0r 10-2 molecules. The agglutination of leukemic and DNP-tagged normal lymphocytes by 200 mug/ml of WGA was completely blocked by 0.1 M N-acetylglucosamine (GlcNAc) while as low a concentration as 0.001 M GlcNAc inhibited the reactivity of untagged cells. Since the agglutination of leukemic and DNP-tagged normal lymphocytes was equally inhibited by GlcNAc, this suggests that the same or similar receptor sites were involved in the two reactions. On the basis of our observations we propose that the initial step in the agglutination of leukemic and DNP-tagged normal lymphocytes by WGA IS THE BINDING OF THE LECTIN TO SPECIFIC RECEPTORS RATHER Than to DNP residues on the cell surface, since leukemic cells tagged with DNFB did not show increased agglutinability.

Acetylglucosamine↗
PubMed2000

[Molecular proof of wheat transformed by total DNA of Leymus racemosus].

Four repetitive DNA sequences (pHv7161, pHv7179, pHv7191 and pHv7293) cloned from barley (Hordeum vulgare) genome were used for a molecular hybridization in the genome of Leymus racemosus (donor), Spring wheat 761 (receptor) and the wheat transformed by total DNA of Leymus racemosus (donor) through pollen tube pathway. Our results indicate that some bands are common in Leymus racemosus and the transformed wheat but absent in Spring wheat 761. The HindIII fragments which are common in Leymus racemosus and the transformed wheat have been cloned. The clone of Leymus racemosus was nominated as pLR980. pLR980 contains the homologous sequences to the four repetitive sequences of barley. The pLR980 cloned from Leymus racemosus was used as probe to study Leymus racemosus, Spring wheat 761 and the transformed wheat. This study demonstrate that pLR980 is homologous in both genome of Leymus racemosus and wheat. Common bands absent in the Spring wheat 761 were also showed in Leymus racemosus and the transformed wheat. pLR980 was proved to be associated with the transform of wheat by total DNA of Leymus racemosus through pollen tube pathway. This provides a direct witness to the exogenous DNA introduction.

DNA, Plant↗
PubMedDate not supplied

[Population of Fusarium spp. in soils from the arid regions and effect of water potential on their growth].

In trials of wheat establishment in irrigated areas in the Patagonian valleys (Picún Leufú), sectors with plants showing symptoms of typical foot-rot were detected. In order to investigate the phytopathogenic mycoflora of these soils (arid zone), the population of Fusarium spp was analysed quali- and quantitatively and its tolerance to water stress by measuring the mycelial growth in the presence of different water potentials. Fusarium spp detected in that type of soil did not coincide with those commonly present in traditional wheat zones. In 100% of the samples analysed the predominant fungus present vas Fusarium equiseti. This species was the one isolated from wheat plants with foot-rot. It was isolated in soil sown with wheat as well as in soils free of wheat. In none of the samples, was the number less than 10,000 propagules/g of soil. In sporadic cases F. moniliforme and F. oxysporum appeared. When comparing, in different water potentials, the growth capacity of isolated species in the arid zone with respect to the other phytopathogenic species common in wheat (F. graminearum an F. poae), it was noted that F. equiseti showed the greatest tolerance to water stress. This species had the capacity to grow in water potentials as low as -12 MPa. This physiological characteristic was manifest in the strains of F. equiseti found in the arid zone and also in those isolated in a wet zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Fusarium↗
PubMed2002

The use of skin prick tests and patch tests to identify causative foods in eosinophilic esophagitis.

BACKGROUND: Eosinophilic esophagitis is a disease entity in which patients have (1) elevated eosinophils on esophageal biopsy and (2) symptoms of gastroesophageal reflux. The symptoms do not improve on aggressive acid blockade but do improve on elimination diet or corticosteroid treatment, which tentatively links food allergies to this disorder. OBJECTIVE: The purpose of this study was to identify potential food antigens in eosinophilic esophagitis. METHODS: Patients with eosinophilic esophagitis were identified by biopsy. Potential food antigens were identified prospectively by skin prick testing and patch testing, which were performed through use of standard methods. Atopic tendencies, demographics, and potential food allergies were identified. Repeat esophageal biopsies were reviewed when possible. RESULTS: A total of 26 patients (22 male, 4 female) with a biopsied-confirmed diagnosis of eosinophilic esophagitis underwent both skin prick testing and patch testing to identify potential causative foods. Milk and egg were the most common positive foods with skin prick testing. Wheat was the most common positive food with patch testing. The patients were advised to avoid positive foods as identified by skin prick testing and patch testing. In all, 18 patients had resolution of their symptoms, 6 patients had partial improvement, and 2 were lost to follow-up. Overall, after intervention, esophageal eosinophil counts improved from 55.8 to 8.4 eosinophils per high-power field. The foods most commonly identified by patients as causing symptoms were milk and egg. CONCLUSION: The combination of skin prick testing and patch testing can identify potential causative foods that might contribute to the pathogenesis of eosinophilic esophagitis.

Adolescent↗
PubMed2004

IgE binding to pepsin-digested water soluble and insoluble wheat proteins.

BACKGROUND: Positive skin prick tests to wheat are a common finding among atopic patients, but only a minor fraction of these patients show immediate clinical symptoms after wheat ingestion. The aim of this study was to evaluate the allergenicity of wheat proteins after pepsin treatments. METHODS: Six patients with positive specific IgE and/or skin prick test to soluble wheat proteins and to gluten were studied. Five of them had no symptoms after wheat ingestion and showed a negative oral challenge test. All sera were analysed with extracts obtained after pepsin hydrolysis during different time periods of water-soluble and insoluble wheat proteins by IgE immunoblotting. RESULTS: A pepsin-sensitive allergen of around 35 kDa was recognized by the five atopic negative wheat oral challenge patients in the undigested water-insoluble extract. A patient showing immediate urticaria after wheat ingestion detected a pepsin-resistant allergen with similar molecular weight. Finally, an inhalation-induced asthma patient recognized water-soluble proteins (of around 14 kDa) that could correspond to the alpha-amylase inhibitors. CONCLUSIONS: Our immunoblotting method shows better correlation with the clinical symptoms than skin prick test and CAP results. Pepsin resistance of the acetic acid-soluble wheat proteins may be responsible for the immediate symptoms of the patient who presented immediate urticaria.

Adolescent↗
PubMed1977

[Purification of peroxidases and separation of isoperoxidases from various plant species (author's transl)].

The partial purification of peroxidase (EC.1.11.1.7) and separation of isoperoxidases by disc electrophoresis from Cucurbita Pepo L., Phaseolus vulgaris L., Cicer arietinum L. and Hordeum, Secale and Triticum sp., have been studied. Peroxidase from fruit of pumpkin and from 6-day-old coleoptiles of French bean and chick pea has been partially purified, 128-, 174-, and 140-fold, respectively. The apparent Km at the optimum pH were: pumpkin (epicarp.), 2.7 X 10(-4) M; barley, common rye and wheat (primary leaves, in all cases), 1.4 X 10(-5), 1.2 X 10(-5) and 3.1 X 10(-5) M, respectively. Isoperoxidases have been separated by disc electrophoresis on 7% polyacrylamide gel and stained with p-phenylenediamine. Differences in patterns of anodic and cathodic isozymes were observed: 3 isozymes from fruits of pumpkin, 4 from French bean, 4 from chick pea, 11 from leaves of barley, 10 from leaves of common rye and 9 from leaves of wheat.

Fruit↗
PubMedDate not supplied

[Molecular marker mapping of the gene resistant to common bunt transferred from Aegilops cylindrica into bread wheat].

Introgression lines 5/55-91 and 378/2000 of bread wheat contain the gene of resistance to Tilletia caries (DC.) Tul. transferred from Aegilops cylindrica Host. Using bulked segregant analysis with ISSR and SSR PCR the lincage of microsatellite locus Xgwm 259 with the gene of common bunt resistance has been identified in F2 population of 378/2000 x Lutestens 23397. DNA mapping made it possible to localize this highly effective gene in the intercalary region of the long arm of wheat chromosome 1B at the distance of 7.6-8.5 cM of the microsatellite Xgwm 259 locus which thus can be used in wheat breeding for selection of genotype resistance to common bunt.

Crosses, Genetic↗
PubMed1998

Wheat sensitization and work-related symptoms in the baking industry are preventable. An epidemiologic study.

A cross-sectional study was conducted among 393 workers from 21 bakeries to study the relationship between wheat allergen exposure and wheat sensitization and work-related allergic symptoms. Exposure to wheat allergens was characterized by a recently developed and validated immunoassay. Specific IgE antibodies against wheat flour and common allergens were measured by immunoassays, and work-related allergic symptoms were registered by questionnaire. A strong and positive association was found between wheat flour allergen exposure and wheat flour sensitization. This relationship was steepest and strongest in atopics. Prevalence ratios for high and medium wheat allergen exposure were 5.2 (95% confidence interval [CI], 1.6-16.2), and 2.7 (0.5-14.5) for atopic workers, and 2.5 (0.8-7.5) and 1.4 (0. 3-6.4) for nonatopics, compared with workers with low wheat allergen exposure. In sensitized bakers those with an elevated allergen exposure had more often work-related symptoms, with prevalence ratios for high and medium wheat allergen exposure of 3.5 (CI 1.6-7. 5) and 2.6 (CI 0.9-7.8), respectively, compared with workers with low wheat allergen exposure. The existence of exposure-sensitization gradients suggests that work-related sensitization risk will be negligible when exposure levels will be reduced to average exposure concentration of 0.2 microgram/m3 wheat allergen or approximately 0.5 mg/m3 inhalable dust during a work shift.

Adult↗
PubMed2005

[Features of crossability, haploidy and polyembryony in hybrid combinations between common barley Hordeum vulgare L. (2n = 14) and wheat-rye substitution lines Triticum aestivum L., cultivar Saratovskaya 29/Secale cereale L., cultivar Onokhoiskaya].

The role of individual chromosomes of rye in the manifestation of crossability and seedling development in hybrid combinations between common barley Hordeum vulgare L., cultivar Nepolegayushchii (2n = 14) and five wheat-rye substitution lines Triticum aestivum L., cultivar Saratovskaya 29/Secale cereale L., cultivar Onokhoiskaya (2n = 40 wheat + 2 rye chromosomes). Crossability, which was measured by two parameters--frequency of set grains and frequency of grains with embryos--was shown to be significantly affected by each of the five rye chromosomes examined: 1R, 2R, 3R, 5R, and 6R; the development of barley haploids was affected by rye chromosomes 1 R, 3R, and 5R. We were the first to demonstrate that polyembryony could be induced by mutual effects of barley cytoplasm and rye chromosome 1R. Possible mechanisms controlling the development of haploids and twins in hybrid combinations H. vulgare x T. aestivum/S. cereale are discussed. The conclusion is drawn that hybrid combinations between common barley and wheat-rye substitution lines can serve as new models for studying incompatibility mechanisms in distant crosses and genetic control of parthenogenesis.

Chimera↗
PubMed1998

Chicken meat induces oral allergy syndrome: a case report.

BACKGROUND: The term oral allergy syndrome (OAS) describes an IgE-mediated reaction that takes place minutes after ingestion of some food to which the organism is previously sensitised. The clinical manifestations are typically localized to the mouth and throat. Oral allergy syndrome is commonly elicited by fresh fruits and vegetables, especially in subjects with hypersensitivity to pollens. METHODS: We report a patient with OAS following intake of chicken meat. We performed (1) skin prick test to chicken meat, egg, milk, and wheat and to common inhalants, (2) determination of serum specific IgE, (3) histamine release test, and (4) in vitro antigen-specific production of sulphidoleukotrienes and challenge test with chicken meat. RESULTS: Skin prick test was positive only for chicken meat. The patient had serum specific IgE, positive histamine release test, and specific production of sulphidoleukotrienes to chicken meat. We confirmed these findings by means of the challenge test.

Administration, Oral↗
PubMed1995

Delayed neuropathy in pigs induced by isofenphos.

In 1990 an outbreak of ataxia occurred in over 700 pigs in the north of England. Epidemiological studies demonstrated that the disorder was associated with the consumption of feed from a particular supplier and that one component (wheat screenings) was common to the batch of feed with which the ataxia was associated. An analysis of the feed demonstrated the presence of an organophosphorus pesticide, later identified as isofenphos, a pesticide not approved for use in the United Kingdom. The wheat screenings had been imported from France and the warehouse in which they had been stored was contaminated with isofenphos, which is approved for restricted use in France. Isofenphos is known to cause delayed neuropathy. The dose to which the pigs were theoretically exposed would be expected to have resulted in neuropathy (manifested as ataxia).

Acetylcholinesterase↗
PubMed2006

Quantification of genetic relationships among A genomes of wheats.

The genetic relationships of A genomes of Triticum urartu (Au) and Triticum monococcum (Am) in polyploid wheats are explored and quantified by AFLP fingerprinting. Forty-one accessions of A-genome diploid wheats, 3 of AG-genome wheats, 19 of AB-genome wheats, 15 of ABD-genome wheats, and 1 of the D-genome donor Ae. tauschii have been analysed. Based on 7 AFLP primer combinations, 423 bands were identified as potentially A genome specific. The bands were reduced to 239 by eliminating those present in autoradiograms of Ae. tauschii, bands interpreted as common to all wheat genomes. Neighbour-joining analysis separates T. urartu from T. monococcum. Triticum urartu has the closest relationship to polyploid wheats. Triticum turgidum subsp. dicoccum and T. turgidum subsp. durum lines are included in tightly linked clusters. The hexaploid spelts occupy positions in the phylogenetic tree intermediate between bread wheats and T. turgidum. The AG-genome accessions cluster in a position quite distant from both diploid and other polyploid wheats. The estimates of similarity between A genomes of diploid and polyploid wheats indicate that, compared with Am, Au has around 20% higher similarity to the genomes of polyploid wheats. Triticum timo pheevii AG genome is molecularly equidistant from those of Au and Am wheats.

DNA Fingerprinting↗
PubMed2002

Factors affecting capture of Cryptolestes ferrugineus (Coleoptera: Laemophloeidae) in traps placed in stored wheat.

Cryptolestes ferrugineus (Stephens), the rusty grain beetle, infests grain externally and is a common pest of stored wheat throughout the world. Detection and population estimation of this insect are important in avoiding discounts at the point of sale. Laboratory experiments compared number of insect captures in the WNB II probe and PC trap in stored grain with a known insect density. Capture rates were strongly related to insect densities in wheat. In a simultaneous test of insect density, ranging from one to three insects per kilogram, and temperatures between 20 and 40 degrees C, insect captures in WB II probe traps increased linearly with insect density in the grain but had a quadratic response to temperature. Hole density, ranging from 40 to 120 holes along a 15-cm stretch of the trap body, was unrelated to number of insect captures. Probe trap diameters ranging from 26 to 60 mm were also unrelated to insect captures. Finally, dead rusty grain beetles were recovered in probe traps. The recovery of dead insects increased with insect density when insects were found in an aggregated dispersal pattern, such as would be found following phosphine fumigation of grain. Experiments discussed here will help grain managers understand how probe traps may be used in C. ferrugineus population estimation.

Animals↗
PubMed1994

Intestinal transport and fermentation of resistant starch evaluated by the hydrogen breath test.

OBJECTIVE: To study fermentability of different samples of resistant starch (RS), compared to one another and to lactulose, and to study the effect on gastric emptying of addition of RS to test meal. Finally to study if adaptation to RS results in a measurable change in fermentation pattern, (H2/CH4 production). Sources of RS: Raw potato starch (RPS), 58% RS; corn flakes (CF), 5% RS; hylon VII high amylomaize starch, extrusion cooked and cooled (HAS) 30% RS; highly retrograded hylon VII high amylomaize starch (HRA) 89% RS. DESIGN: (1) Fermentation: seven healthy volunteers ingested in randomized order 50 g RPS, 100 g CF, 75 g HAS, 25 g HRA. End-expiratory H2/CH4 was measured every 30 min for 12 to 22 hours post-ingestion as a measure of fermentation. A dose-response study of RPS, 5, 10, 25, 50, 75 and 100 g was performed. (2) Adaptation: In five 3-week periods seven volunteers added daily to their usual diet 50 g of either RPS, HAS, oat bran, wheat bran or common maize starch. The polysaccharides were administered in randomized order. The test periods were separated by 1 week's wash out. Basic end-expiratory H2/CH4 was measured once a week prior to and during the test periods. (3) Gastric emptying: The rate of increase in blood glucose was measured after test meals consisting of 50 and 100 g of RPS, 50 g HAS and 50 g glucose dissolved in a gel, alone, and mixed with 25 g of RPS. As controls we chose wheat bran and oat bran. RESULTS: (1) We found that RPS is fermentable, although the cumulated excessive H2 production after 50 g RPS corresponding to 29 g RS was clearly less than after 10 g lactulose. The time from ingestion of RPS to a sustained increase in end-expiratory H2 (apparent transit time; 5-11 h) was longer than lactulose (1-4 h), indicating either a slow passage through the small intestine or a slow fermentation rate. 100 g of corn flakes (4.6 g RS) resulted in a measurable increase in H2 production, equivalent to 10-20 g RPS, whereas neither of the two samples of hylon VII high amylomaize resulted in any significant increase in H2 production. The dose-response study with RPS showed that even 5 g of RPS resulted in a measurable increase in end-expiratory H2, and increasing doses from 5 g to 100 g resulted in a seemingly exponential increase in H2 production. (2) 3 weeks' daily administration of HAS resulted in a slightly elevated increase in basic end-expiratory H2, although the increase did not reach statistical significance. RPS resulted in a sustained increase in basic end-expiratory H2. Both RS samples increased measurable end-expiratory CH4 in volunteers with measurable CH4 production after a lactulose load, but 3 weeks' daily challenge with these slowly fermentable substrates did not increase measurable CH4 in volunteers, who prior to the study only produced CH4 intermittently. (3) The rate of increase in blood sugar was unaffected by addition of RS or non-starch-polysaccharides to the test meal, indicating that addition of the polysaccharides does not affect gastric emptying. CONCLUSIONS: A fraction of RPS is resistant to digestion in the small intestine, and it is fermentable by the colonic microbial flora. RS from CF, HAS and RPS give very different H2 responses, either due to differences in digestion patterns or fermentation patterns. Short-term adaptation (3 weeks) to HAS or RPS does not change the H2/CH4 response. RS does not affect gastric emptying of a test meal consisting of glucose dissolved in a gel.

Adaptation, Physiological↗