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PubMed1991

Feed intake and digestion by Holstein steers fed warm or cool season grass hays with corn, dried molasses, or wheat middlings.

This study determined the effects of adding a small amount of dried molasses to supplemental corn and of supplementing with corn, wheat middlings, or corn-wheat middlings mixture on intake and digestion by Holstein steers fed warn or cool season grass hays. Eight steers (175 kg BW), in two simultaneous Latin squares, were fed, once daily, bermuda-grass (72% NDF) or ryegrass-wheat (58% NDF) hay ad libitum, alone or with approximately .05% BW of dried molasses (with 31% roughage), 5% BW of ground corn, or both. Adding dried molasses to corn decreased feed intake but did not affect digestible OM intake. Total tract digestion of fiber from bermudagrass tended to be enhanced by adding dried molasses to corn. Eight steers (193 kg BW) were used in an experiment with the same design in which similar forages were fed alone or with corn (.5% BW), wheat middlings (.63% BW), or .25% BW of corn plus .31% BW of middlings. Feed intake for both grasses was similar among supplements. Wheat middlings depressed total tract fiber digestion more than corn with both forages. Supplementation with corn depressed fiber digestion slightly more with ryegrass-wheat than with bermudagrass, but wheat middlings had a slightly greater depressing effect on fiber digestion with bermudagrass. Associative effects of mixing corn and wheat middlings in OM digestion and digestible OM intake were negative for bermudagrass and positive for ryegrass-wheat. Interaction among characteristics of basal forage and concentrate modulated feed intake and digestion by ruminants.

Animal Feed↗
PubMed1997

Effects on nutrient digestion of wheat processing and methods of tallow addition to the diets of lactating dairy cows.

Five multiparous Holstein cows in midlactation that were fitted with ruminal and duodenal cannulas were used in a 3 x 5 incomplete Latin square. The objective of this study was to examine the effects on nutrient digestion of wheat processing and method of tallow addition to the diets of lactating dairy cows. Diets consisted of 45% forage and 55% concentrate, and each diet contained 20% wheat and 2% tallow (as-fed basis). Treatments were dry-rolled wheat with tallow added to the concentrate, steam-rolled wheat with tallow added to the concentrate, and steam-rolled wheat with tallow added first to the wheat. The dry matter intake; digestion of starch, fiber, and fatty acids; ammonia N concentration; and molar proportions of volatile fatty acids in ruminal fluid were not affected by treatments. The apparent digestibility in the total tract of organic matter and nitrogenous compounds was significantly higher for the steam-rolled treatment with tallow added first to the wheat. Mean ruminal fluid pH was similar across treatments; however, cows fed the diet containing steam-rolled wheat with tallow added first to the wheat had the smallest pH change from 0 to 2 h postfeeding. Milk yield did not differ, regardless of cow diet. Method of tallow addition had marked effects on the apparent digestibility of organic matter and N in the total tract of lactating dairy cows.

Animal Nutritional Physiological Phenomena↗
PubMed1987

Influence of a wheat diet on mortality of broiler chickens associated with necrotic enteritis.

In an experiment to determine methods of incorporating soft winter wheat into broiler diets, a significant increase in mortality was observed in broilers fed wheat in crumbled diets. This increase in mortality was associated with necrotic enteritis with Clostridium perfringens indicated as the causative pathogen and complicated by a coccidiosis outbreak. When yellow corn was used in the diet, mortality was 2.9%. Use of all wheat, ground with a hammer mill, increased mortality to 28.9%. However, roller mill-ground wheat diet resulted in a mortality of 18.1%. When the grain component was approximately 50% wheat and 50% corn, mortality was 12.6% for broilers fed hammer mill-ground wheat and 3.4% for roller mill-ground wheat. Grain and feed were tested for several mycotoxins. Low levels of deoxynivalenol were found in both corn and wheat diets, but no differences between the corn and wheat-based diets were found that would explain the incidence of enteritis.

Animal Feed↗
PubMed2004

Wheat gluten causes dendritic cell maturation and chemokine secretion.

Wheat gluten causes gut inflammation in genetically predisposed individuals. We tested the hypothesis that wheat gluten is not only a target of adaptive immunity, but also modulates the function of APC. Dendritic cells (DC) derived from the bone marrow of BALB/c mice were exposed to chymotrypsin-treated wheat gluten. This induced DC maturation as estimated by all surface markers tested (MHC class II, CD40, CD54, and CD86). The effect was dose dependent, and, at 100 microg/ml gluten matched that caused by 10 ng/ml LPS. A role of endotoxin contamination was ruled out by demonstrating the resistance of wheat gluten effects to LPS antagonist polymyxin B. DC from LPS nonresponder strain C3H/HeJ were affected by wheat gluten, but not by LPS. Proteinase K-digested wheat gluten was unable to stimulate DC maturation. Wheat gluten induced a unique secretion pattern of selected cytokines and chemokines in DC. Classic pro- or anti-inflammatory mediators were not produced, in contrast to LPS. Rather, chemokines MIP-2 and keratinocyte-derived cytokine were secreted in large amounts. We conclude that wheat gluten lowers the threshold for immune responses by causing maturation of APC, by attracting leukocytes and increasing their reactivity state. In the presence of an appropriate genetic predisposition, this is expected to increase the risk of adverse immune reactions to wheat gluten or to other Ags presented.

Animals↗
PubMed2001

An exploratory quantitative risk assessment for high molecular weight sensitizers: wheat flour.

OBJECTIVE: Quantitative risk assessments have been made for wheat dust and allergen exposure and wheat sensitization using classical epidemiological approaches based on simple categorizations in exposure groups. Such analyses suggest the existence of an exposure threshold level for wheat specific sensitization and were used as input in recently conducted risk assessments for wheat flour by the American Conference of Governmental Industrial Hygienists and the Dutch Expert Committee on Occupational Standards. More advanced statistical analyses were applied using generalized additive modeling and smoothed plots to evaluate the shape of the exposure response relationship in greater detail and evaluate the presence of exposure thresholds. METHODS: Data were used from a recently conducted epidemiological study in bakery workers. Information was available on wheat sensitization (IgE antibodies), inhalable dust levels and wheat allergen levels. Initial analyses were based on simple exposure categorizations for inhalable dust and allergen exposure. A more detailed analysis using non-parametric generalized additive models (GAM models) and smoothing plots allowed inspection of the presence of an exposure threshold of evaluation of 'no' or 'lowest observed effect levels' (NOELs, LOELs) using exposure data on the individual level. RESULTS: All analyses showed an increasing sensitization risk with increasing exposure. The classical epidemiological analyses gave evidence for the existence of an exposure threshold or 'no observed effect level (NOEL)' for specific wheat sensitization between 0.5 and 1 mg/m3 of inhalable dust. The more advanced analyses did not suggest any evidence for the existence of an exposure threshold. However, estimates of a LOEL obtained by considering an arbitrary increase in sensitization risk between 1.5 and 2 as undesirable, were close to the NOEL from the classical analyses and would therefore not lead to an essentially different exposure limit. The criterion of an increase in wheat sensitization risk was based on the risk in non-wheat dust exposed populations. CONCLUSION: Exposure response modeling using different classical epidemiological approaches and advanced statistical methods resulted in health based LOEL or NOEL estimates within a relatively close range. But when sensitization accompanied by asthma or rhinitis symptoms was considered as critical endpoint, steeper exposure-response relationships were observed which would lead to lower LOEL values.

Adolescent↗
PubMed2002

[Study of the backcross progeny of barley-wheat hybrids by the RAPD and RAMPO methods].

The genomes of alloplasmic wheat lines were analyzed by PCR-based methods: random amplified polymorphic DNA (RAPD) and random amplified microsatellite polymorphism (RAMPO). Lines L-16(1) and L-17(2) were obtained by three backcrosses and line L-79(10), by four backcrosses of the barely-wheat hybrid Hordeum vulgare (2n = 14) (variety Nepolegayuschii) x Triticum aestivum (2n = 42) (variety Saratovskaya 29) with different common wheat varieties. These lines proved to be euploid (2n = 42). The aneuploid line L-9 (2n = 43 + t) was obtained after a second backcross of the hybrid H. geniculatum All. (2n = 28) x T. aestivum (2n = 42) (Pyrotrix 28) with the variety Pyrotrix 28. The RAPD patterns of L-16(1) and L-17(1) contained fragments present only in the patterns of the parental wheat varieties and, in addition, fragments absent from the latter. This fragment from the pattern of L-16(1) was cloned. Analysis of its primary structure showed that the difference between L-16(1) and the parental wheat genotypes may be related to a mutation that had occurred during the development of the alloplasmic line at the binding site of an arbitrary primer. The genomes of plants of the lines L-79(10) and L-9 contain, in addition to the RAPD fragments of wheat, those characteristic of barley. RAMPO revealed higher polymorphism level among wheat varieties than that detected by RAPD. The hybridization patterns of the lines L-16(1), L-17(1), and L-79(10) contained fragments specific for wheat, and the patterns of L-9 contained both wheat and barley fragments.

Base Sequence↗
PubMed2004

An attempt to protect winter wheat against Gaeumannomyces graminis var. tritici by the use of rhizobacteria Pseudomonas fluorescens and Bacillus mycoides.

Pseudomonas fluorescens strains III107 and II21 and Bacillus mycoides strains JC192 and K184, stimulating growth of winter wheat, were chosen for the studies. The bacterial strains inhibited on agar nutrient medium the growth of Gaeumannomyces graminis var. tritici (Ggt)--the pathogenic fungus causing take-all on wheat. Both strains of pseudomonads synthesized relatively high amounts of Fe3+ chelators. The strains of bacilli were characterized by the very fast spreading on agar media. Furthermore, strain II21 was highly cyanogenic, and strain JC192 highly chitinolytic. Bacterization of winter wheat seeds (especially with strains III107 and JC192) significantly reduced the percentage of the plants infested with the pathogen in the 28 day glasshouse pot experiment. In the plot experiment, the winter wheat seeds were inoculated with a mixture of strains III107, II21 and JC192. Due to the bacterization the yield of wheat grain and straw was higher in comparison to the series with Ggt alone by 122% and 75%, respectively, but it amounted only to 45% and 43% of the control series not contaminated with Ggt. The decrease of percentage of wheat ears with weight less than 500 mg from 61% in Ggt-series to 25% in Ggt-bacterized-series, and especially the decrease of percentage of wheat ears with weight less than 200 mg from 43% to 14% additionally indicate the partial protection of the winter wheat against Ggt by the rhizobacteria. In the experimental series not contaminated with Ggt the percentage of these wheat ears fractions did not exceed 3% and 0.5%, respectively.

Ascomycota↗
PubMed2005

[Influence of PO4(3-) and citrate on REE accumulation and fractionation in wheat].

This paper has studied the influence of phosphate (Pi, one of inorganic ligands) and citrate (Cit, one of organic ligands) on accumulation and fractionation of REEs in wheat based on aqueous culture, added with extraneous mixed REEs (MRE) and ICP-MS analysis technology. The results show that initial phosphate (Pi) solution of different levels followed by exposure to fixed-MRE solution has no significant effects on accumulation of the total concentrations of REEs (sigma REE) in the wheat roots, but it decrease the REE dramatically in the wheat leaves. Simultaneous culture of wheat with mixture of MRE and citrate solution caused obvious decreases of the sigma REE both in wheat roots and leaves. Compared to the control (no Pi or citrate was added), the distribution and fractionation characters of MRE had M-type tetrad effect and MREE enrichment in wheat roots, and W-type tetrad effect and HREE enrichment in wheat leaves. Different levels of Pi had no significant effects on the tetrad effect of MRE, but it notable increased the enrichment of HREE in wheat leaves. Added with citrate of different levels led the fractionation of REE decreasing gradually in wheat roots and leaves, as the concentration of citrate > or = 150 micromol x L(-1), light REE (LREE) enrichment both existed in the roots and leaves.

Citric Acid↗
PubMed1988

Initiation factors that bind mRNA. A comparison of mammalian factors with wheat germ factors.

Three mammalian eukaryotic initiation factors (eIF) are required for the ATP-dependent binding of mRNA to the 40 S ribosomal subunit. These three factors, eIF-4A, eIF-4B, and eIF-4F, have also been isolated from wheat germ. Three assays were used to measure the ability of the wheat germ factors to interact with and/or substitute for the mammalian factors. Two assay systems were used to measure partial reactions involving the interaction of the three factors, ATP, and mRNA: 1) RNA-dependent ATP hydrolysis and 2) cross-linking of the factors to the 5' cap of oxidized mRNA. A third assay system was used to measure the ability of the factors to support initiation of protein synthesis. The results of the ATP hydrolysis and cross-linking experiments indicate that the wheat germ factors can interact with or substitute for the mammalian factors. Wheat germ eIF-4A appears to be functionally equivalent to mammalian eIF-4A. Wheat germ eIF-4B and eIF-4F appear to be isozymes possessing functions similar to mammalian eIF-4F. Wheat germ eIF-4B does not appear to be a functional equivalent to the mammalian eIF-4B. In a complete translation system from wheat germ, mammalian factors partially substitute for wheat germ factors, whereas the wheat germ factors are ineffective in the mammalian system.

Adenosine Triphosphate↗
PubMed1985

A radioimmunoassay for wheat gliadin to assess the suitability of gluten free foods for patients with coeliac disease.

Coeliac disease is a clinical condition characterised by malabsorption secondary to abnormalities of the small intestine. The condition is known to be exacerbated by wheat gliadin, rye, barley and possibly oats. The only assays that are available for testing for the presence of wheat gluten in foods are double diffusion against rabbit anti-gliadin antiserum and measurement of Kjeldahl nitrogen in products derived from wheat flour. We have developed a radioimmunoassay for wheat gliadin with a detection limit of 1 ng. Nominally gluten free foods based on wheat starch have been shown to contain up to 1.9 X 10(-2)% wheat gliadin. Bread made from Nutregen wheat starch which has now been withdrawn contains 6.4 mg gliadin per standard 30 g slice. A radioimmunoassay for wheat gliadin could be used to define standards for the suitability of gluten free products based on wheat starch for patients with coeliac disease.

Celiac Disease↗
PubMedDate not supplied

[Changes in blood eosinophils and nonspecific bronchial reactivity after exposure tests to wheat flour and TDI].

We studied non-specific bronchial responsiveness (NSBR) and blood eosinophils before and 24 hours after a bronchoprovocation test (SBPT) with wheat flour (22 cases) and TDI (32 cases). Twelve patients developed asthma after exposure to wheat flour (7 early and 5 dual/late asthma), and 12 after exposure to TDI (6 early and 6 late/dual asthma). Responders and non responders to wheat flour exposure were similar for all general characteristics except IgE levels (p = 0.036) and NSBR (p = 0.047). A higher degree of airway responsiveness to methacholine was the only characteristic which differentiated responders from non responders to TDI exposure (p = 0.043). Airway responsiveness, assessed 24 hours after the SBPT (44 cases), did not show any change compared to pretest values; the data were similar both among non responders to wheat flour (Wilcoxon p = 0.1) or to TDI (p = 0.2) and responders to TDI (p = 0.6) or wheat flour (p = 0.3); also no significant changes were observed among early and dual/late asthma caused by wheat flour and TDI. Twenty-four hours after the SBPT, blood eosinophils were higher than pretest, but only among the 24 patients with asthma (Wilcoxon p = 0.002); the blood eosinophil increase was statistically significant among patients with early and late/dual asthma caused by wheat flour, and among those with early and late/dual TDI asthma. In our study, NSBR was confirmed as a common feature of occupational asthma, either IgE mediated (wheat flour) or non-IgE mediated (TDI). Twenty four hours after the specific exposure, among patients with asthma induced by wheat flour and TDI, there was an increase in blood eosinophils while in the same time interval no variation in non-specific bronchial responsiveness was observed.

Adolescent↗
PubMed1976

Opposing effects of mitogenic and nonmitogenic lectins on lymphocyte activation. Evidence that wheat germ agglutinin produces a negative signal.

In an effort to clarify the mechanism by which certain plant lectins induce lymphocyte activation, we have studied amino acid (amino[14C]isobutyric acid) uptake in purified human lymphocytes exposed to mitogenic and nonmitogenic lectins. In confirmation of earlier work, mitogenic lectins (concanavalin A and two phytohemagglutinins) produced a dose-related, 2- to 10-fold increase in aminoisobutyric acid transport. Changes occurred as early as 2 hours and reached a maximum after 18 hours. The stimulation by concanavalin A was inhibited by alpha-methyl-D-mannoside but not by other selected monosaccharides, indicating that the effect is modulated through specific carbohydrate receptors. In contrast to the stimulation with concanavalin A and phytohemagglutinin, the nonmitogen wheat germ agglutinin inhibited aminoisobutyric acid transport, both in the presence and absence of the mitogenic lectins. The inhibition was seen over a broad wheat germ agglutinin dose range, was prevented by N-acetylglucosamine, a known inhibitor of wheat germ agglutinin binding, and did not appear to be associated with cytotoxicity. Comparative binding studies with radiolabeled concanavalin A and wheat germ agglutinin demonstrated that differences in transport occurred in cells containing comparable numbers of bound lectin molecules indicating that the failure of wheat germ agglutinin to stimulate a response was not a result of ineffective binding. The lack of stimulation by wheat germ agglutinin was not due to its inability to interact multivalently with membrane receptors since this lectin is divalent, produces capping and agglutination, and continues to inhibit aminoisobutyric acid transport even after the minimum valence was increased to 4 by cross-linking with glutaraldehyde. In contrast both divalent and tetravalent concanavalin A produced stimulation. Competitive binding studies with soluble wheat germ agglutinin or lectin attached to 300 A latex spheres revealed little or no competition for binding sites with radiolabeled concanavalin A, suggesting the two lectins are interacting with different receptors. This was further suggested by kinetic studies of aminoisobutyric acid transport which indicated that wheat germ agglutinin was probably affecting both the Vmax and Km of transport, whereas concanavalin A affected only the Vmax. While the mechanism by which concanavalin A and wheat germ agglutinin produce opposing effects on amino acid transport is not clear, since the two lectins appear to be interacting with different surface receptors we would suggest that they are perturbing microanatomically and functionally different domains on the lymphocyte plasma membrane.

Aminoisobutyric Acids↗
PubMed1986

Structural and conformational features that affect the interaction of polylactosaminoglycans with immobilized wheat germ agglutinin.

We examined the interaction between immobilized wheat germ agglutinin and the large, polylactosamine-containing glycans from human erythrocytes and human K-562 erythroleukemic cells. Three classes of interaction were identified. One class of glycan was merely retarded during chromatography. The other two classes were retained and could be distinguished by their ease of displacement with N-acetylglucosamine (GlcNAc); one was a moderate-affinity fraction displaced by 0.1 M GlcNAc and the other was a high-affinity fraction subsequently displaced by 1.0 M GlcNAc. A relatively small fraction of the K-562 polylactosamines were in the high-affinity class. We explored the role that fucose and sialic acid substitutions play in the strength of the lectin-glycan interaction. Although sialic acid is recognized by wheat germ agglutinin, sialylation was not required for the high-affinity interaction, and the presence of sialic acids actually prevented some glycans from binding with high affinity. In contrast, fucose is not part of the binding determinant, yet the removal of fucose resulted in decreased affinity. The possibility that some of these changes in affinity were the result of conformational changes was explored using matrices that had wheat germ agglutinin immobilized at different densities. At low wheat germ agglutinin densities, adult and fetal erythroglycans and K-562 glycophorin-like glycans were not retained by the matrix. As the density increased, the proportion of glycans that were retarded, and ultimately retained, increased. While these increases in the proportions retained occurred in parallel for the three different glycans, the apparent affinities of the glycan-lectin interactions differed. The glycophorin-like glycans were always readily displaced by 0.1 M GlcNAc, even at higher wheat germ agglutinin densities. In contrast, as the wheat germ agglutinin density increased, the proportion of erythroglycans that could be displaced by 0.1 M GlcNAc decreased; at 10 mg/ml immobilized wheat germ agglutinin, greater than 80% of the erythroglycans exhibited this tighter interaction. We suggest that this higher affinity interaction is the result of the large glycans spanning adjacent wheat germ agglutinin molecules, and is determined by the proximity of these molecules and the conformation of the glycans.

Amino Sugars↗
PubMed2005

Wheat-dependent exercise-induced anaphylaxis in mice is caused by gliadin and glutenin treatments.

Various foods may be associated with food-dependent exercise-induced anaphylaxis (FDEIAn). However, although the most frequently reported cause of FDEIAn has been wheat, the mechanism of FDEIAn for wheat has remained largely uninvestigated. To investigate the effect of wheat-fractionated proteins on FDEIAn, female B10.A mice (16-20 g) were divided into four groups; i.e. salt-soluble (S-group), gliadin-rich (GLI-group), and glutenin-rich (GLU-group)-sensitized mice, and unsensitized mice. The three sensitized groups were run on a treadmill after oral intake of each wheat-fractionated protein. The mice showed a significant increase in serum IgE, especially in the GLI- and GLU-group. After oral administration of each wheat-fractionated protein, the running time until exhaustion was remarkably shorter for the GLI- and GLU-group than for the S-group and unsensitized mice. The level of intestinal erosion was higher in all the sensitized mice than that in the unsensitized ones after exhaustive running. Furthermore, moderate exercise for 30 min after oral ingestion of each wheat-fractionated protein also induced intestinal erosion in the GLI- and GLU-group. In addition, we observed leaking of gliadin and glutenin proteins out of the intestine into the liver. These results indicated that the main factor involved in wheat-dependent exercise-induced anaphylaxis might be the gliadin and glutenin in wheat proteins.

Anaphylaxis↗
PubMed2006

Screening the allergenic repertoires of wheat and maize with sera from double-blind, placebo-controlled food challenge positive patients.

BACKGROUND: Food allergy to wheat and maize is an increasing factor of deterioration of life quality, especially childhood and can, in rare cases, even induce anaphylaxis. Although omega-5 gliadin from wheat and maize lipid transfer protein have been characterized as major cereal allergens on the molecular level, the list of food allergens is far to be complete. METHODS: To identify the IgE-binding repertoires of wheat and maize we screened respective cDNA libraries displayed on phage surface with sera from patients with a confirmed food allergy. The study included six patients with a positive double-blind, placebo-controlled food challenge (DBPCFC) to wheat, nine patients with a positive DBPCFC to maize, and six patients with anaphylactic reactions after ingestion of wheat. RESULTS: The enriched sequences encoding IgE-binding proteins showed heterogeneous repertoires for both, wheat and maize. The selected wheat repertoire yielded 12, the maize repertoire 11 open reading frames. Among these we identified allergens belonging to already characterized allergens families, such as gliadin, profilin and beta-expansin. Besides, we found novel proteins with high cross-reactive potential, such as thioredoxins, as well as sequences that had so far not been related to cereal allergy at all. The IgE-binding capacity of some selected proteins was evaluated in vitro and cross-reactivity was demonstrated by competition ELISA. CONCLUSION: With regard to the heterogeneity of the characterized sequences as well as to the biochemical nature of the new allergens detected we conclude that wheat and maize-related food allergy is more complex than so far anticipated.

Adolescent↗
PubMed1983

A novel protein programmed by the mRNA conserved in dry wheat embryos. The principal site of cysteine incorporation during early germination.

If bulk mRNA from dry wheat embryos (wheat germ) is used to direct cell-free incorporation of [35S]cysteine into proteins, a striking proportion of the total radioactivity is channeled into a single protein. During early postimbibition development, when protein synthesis is directed by the mRNA conserved in dry embryos, incorporation of cysteine is preponderantly (20-25%) directed into synthesis of this one protein: the 'early' cysteine-labeled protein (Ec). When conserved mRNA from the dry embryos has been fully degraded, as when cellular or cell-free protein synthesis is directed by the mRNA in germinated embryos, synthesis of Ec is not detected. Reliable detection of Ec requires prior alkylation of wheat embryo proteins, and it was especially interesting to find that when wheat embryo proteins are alkylated by iodo[14C]acetamide, two proteins co-dominate the distribution of radioalkylated products in dodecylsulphate/polyacrylamide gels: Ec and wheat germ agglutinin. Using co-electrophoresis with the isotopically labeled protein to detect a dye-staining counterpart, Ec has been purified by combined cation-exchange and gel-filtration chromatography of alkylated wheat germ proteins. The purified protein can be recovered in milligram quantity (5-10 mg/100 g wheat germ) and compositional analysis shows that it is unusually rich in cysteine (approx. 15%) and glycine (approx. 17%), as is wheat germ agglutinin.

Alkylation↗
PubMed2026

Wheat breeding during and after the "green revolution" contributed to the reduced use of elite nitrogen metabolism alleles linked to nitrogen use efficiency.

The wheat "Green Revolution (GR)" that occurred from the 1960s to the 1970s significantly enhanced the harvest index and resistance to lodging, thereby increasing grain production, but at the cost of reduced nitrogen (N) use efficiency (NUE) in wheat. The NUE of wheat is mainly regulated by N metabolism genes (NMGs). However, the evolutionary process of NMGs during GR and post-GR wheat breeding, as well as which of them affect NUE, remains unclear. Here, we collected 265 wheat varieties that were released before, during, and after the GR and investigated grain yield per plant and 24 other traits under different N supply conditions. Next, we identified the genotypes of these wheat varieties using a 100 K targeted sequencing array. Then, we systematically analyzed the signatures in the genomes of GR and post-GR released varieties compared with pre-GR released varieties through population divergence (Fst) and nucleotide diversity (π) ratio analyses, and found that 41 NMGs were located within the selective sweep regions during the GR and post-GR breeding. We further identified 118 quantitative trait loci (QTLs) involved in regulating NUE through genome-wide association studies (GWAS). Four NMGs-NRT1 AND PEPTIDE TRANSPORTER FAMILY 2.7-D (TaNPF2.7-D), TaNPF2.3-D, TaNPF2.7 L-D, and QUASIMODO2-B (TaQUA2-B)-were located within overlapping regions of selective sweeps and NUE-related QTLs. Notably, the elite haplotypes of these genes for NUE are less utilized in GR and post-GR released cultivars. Furthermore, we found that TaNPF2.7-D positively regulates nitrate exudation as well as the wheat development. Collectively, our findings uncover an important reason for the reduction in NUE in modern cultivars and provide a valuable resource for improving wheat NUE.

Triticum↗
PubMed1991

Increase in cell surface wheat germ agglutinin binding in a rat hepatoma cell line dRLa 74 treated with concanavalin A.

Wheat germ agglutinin binding to a rat hepatoma cell line dRLa 74 treated with concanavalin A was studied. It increased depending on the concanavalin A concentration in the culture medium. The cells exhibited about twofold increase in wheat germ agglutinin-binding when pretreated with 50 micrograms/ml of concanavalin A for 48 h. The wheat germ agglutinin binding sites were shown to be localized at the cell surface by lectin-histochemistry. Wheat germ agglutinin blotting of microsomal membrane proteins showed a broad wheat germ agglutinin-reactive band with an apparent molecular weight of 90 to 100 kDa. Loss of wheat germ agglutinin binding to dRLa 74 cells and the glycoprotein after neuraminidase treatment suggested that wheat germ agglutinin reacted with cell surface sialyl residues of dRLa 74 cells. The induced change was reversible. Increased wheat germ agglutinin binding returned to the pretreatment level when the concanavalin A-treated cells were subcultured in the absence of concanavalin A. These observations suggest that environmental factors interacting with tumor cell surface sugar moieties may induce reversible epigenetic changes on cell surface carbohydrate structures.

Animals↗