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PubMed2005

[Grain protein content in wheat: genetics of the character and some predictions for its improvement in common wheat].

The results of studies on genetic control of the grain protein content character in common wheat and the attempts of its improvement using traditional breeding approaches and methods of experimental mutagenesis and introgressive hybridization are presented. The evolution of the views on the genetic structure of the character is considered. Possible explanations are given to the fact that the attempts to significantly improve the character in question in common wheat cultivars have failed in spite of long-term genetic and selection studies. Possible lines of further investigation of genetic control of grain protein content and its increase in common wheat are discussed.

Crops, Agricultural↗
PubMed1986

Purification of wheat germ RNA ligase. II. Mechanism of action of wheat germ RNA ligase.

The mechanism of action of purified wheat germ RNA ligase has been examined. ATP was absolutely required for the ligation of substrates containing 5'-OH or 5'-P and 2',3'-cyclic P or 2'-P termini. Ligation of 1 mol of 5'-P-2',3'-cyclic P-terminated poly(A) was accompanied by the hydrolysis of 1 mol of ATP to 1 mol each of AMP and PPi. Purified RNA ligase catalyzed an ATP-PPi exchange reaction, specific for ATP and dATP, and formed a covalent enzyme-adenylate complex that was detected by autoradiography following incubation with [alpha-32P]ATP and separation of the products by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A protein doublet with a molecular weight of approximately 110 kDa, the major product detected by silver staining, was labeled in these reactions. Isolated E-AMP complex was dissociated by the addition of ligatable poly(A), containing 5'-P-2',3'-cyclic P termini, to yield AMP and by the addition of PPi to yield ATP. The unique feature of the reactions leading to an exchange reaction between ATP and PPi and to the formation of an E-AMP complex was their marked stimulation (up to 400-fold) by the addition of RNA. This property distinguishes the wheat germ RNA ligase from other known RNA and DNA ligases which catalyze ATP-PPi exchange reactions and form E-AMP complexes in the absence of substrate. Thus, RNA appears to function in two capacities in the wheat germ system: as a cofactor, to stimulate the reaction of the enzyme with ATP, and as an authentic substrate for ligation.

Adenosine Monophosphate↗
PubMed2001

Intestinal absorbability of wheat allergens, subunits of a wheat alpha-amylase inhibitor, expressed by bacteria.

Wheat CM2, CM3 and CM16 proteins are known as subunits of the tetrameric alpha-amylase inhibitor as well as major allergens to baker's asthma. The purpose of this study is to produce these CM proteins by bacteria in a quantity adequate for studying the penetration characteristics of the CM proteins through intestinal mucosa in rats and Caco-2 cells. cDNAs encoding the mature proteins were expressed in Escherichia coli and purified by an Ni2+-chelating column. The recombinant proteins were radioiodinated and admministered orally to rats or applied to the apical site of the Caco-2 cell monolayer. The radioactivity in the trichloroacetic acid-insoluble fraction, which was mainly composed of peptides with molecular mass less than that of the intact CM proteins, in the serum and the basolateral medium was highest in recombinant CM3. Accordingly, the intestinal absorption of these three proteins in the form present in wheat should be evaluated.

Allergens↗
PubMed2004

[Mechanisms of protective action of wheat germ agglutinin on cell growth in wheat seedling roots under salinity].

Effects of 20 nM wheat germ agglutinin (WGA) on relative growth rate, mitotic index (MI) and the cell area in the root extension zone were investigated in seedling of Triticum aestivum L. under the influence of 2% NaCl. It was elucidated that pretreatment of wheat seedling with WGA prevented a salinity induced inhibition of root cell growth, and accelerated the restoration of cell growth after stress removal. The protective WGA effect on root cell growth may be due, presumably, to reorganization of phytohormone balance caused by WGA treatment, which could lead to accumulation of LAA and decrease in the ABA level.

Plant Growth Regulators↗
PubMed2006

Pyrolytic acrylamide formation from purified wheat gluten and gluten-supplemented wheat bread rolls.

Recent studies have revealed different acrylamide formation mechanisms, e. g. from carnosine (N-beta-alanyl-L-histidine) and aminopropionamide as additional precursors. The occurrence of acrylamide in food matrices devoid of common precursors such as meat supports an additional formation pathway. Gluten was recovered from wheat flour by water extraction. Starch, reducing sugars and amino acids were removed using alpha-amylase and NaCl solution and were completely absent in the purified gluten fraction. The gluten was dry heated at temperatures ranging from 160 to 240 degrees C for 8 to 12 min and analyzed for acrylamide and cinnamic amide using liquid chromatography-tandem mass spectrometry. Acrylamide could be detected up to 3997 microg/kg gluten dry weight. Cinnamic amide was detected and unambiguously identified in the gluten samples, thus confirming the proposed formation of acrylamide from proteins. After gluten addition to bread roll dough, protein pyrolysis to form acrylamide in the complex food matrix was assessed. Contents of asparagine and reducing sugars were diminished due to the addition of the gluten. In contrast to the expectation with respect to the well-established common formation mechanism of acrylamide, it increased from 53.4 to 63.9 microg/kg (+20%), which was in good correlation with the higher proportion of gluten. As demonstrated by the t-test, the increase in acrylamide was significant when comparing 0 and 15% gluten addition. Additionally, cinnamic amide could be found in crusts of bread rolls. Thus, evidence for pyrolytic formation of acrylamide from wheat gluten was provided.

Acrylamide↗
PubMed2001

Evidence that soilborne wheat mosaic virus moves long distance through the xylem in wheat.

Soilborne wheat mosaic virus (SBWMV) is a member of the genus Furovirus of plant viruses. SBWMV is transmitted to wheat roots by the plasmodiophorid vector Polymyxa graminis. Experiments were conducted to determine the path for SBWMV transport from roots to leaves. The results of immunogold labeling suggest that SBWMV enters and moves long distance through the xylem. SBWMV may enter primary xylem elements before cell death occurs and then move upward in the plant after the xylem has matured into hollow vessels. There is also evidence for lateral movement between adjacent xylem vessels.

Biological Transport↗
PubMed2002

Cloning and mapping of genes involved in wheat-leaf rust interaction through gene-expression analysis using chromosome-deleted near-isogenic wheat lines.

Molecular markers on wheat chromosome 6BL were isolated using mRNA differential display. Two wheat isolines inoculated with Puccinia recondita were analysed: Sinvalocho MA line carrying the Lr3 gene for leaf rust resistance on distal chromosome 6BL, and a rust-susceptible derivative of the Sinvalocho MA line with a deletion at the distal end of chromosome 6BL. Comparison of mRNA fingerprinting profiles, obtained from control and rust-inoculated plants, let to the isolation of 34 differentially displayed cDNAs. All these genes, except TaRr16, were up-regulated in the rust-inoculated resistant line. TaRr16 has constitutive expression in the rust-resistant line while no expression was detected in the rust-susceptible line. A number of those cDNAs revealed homology to genes previously identified in other plant-pathogen interactions. Two out of the 34 cDNAs, mapped in the distal part of chromosome 6BL and TaRr16, was genetically linked to the Lr3 gene. DNA sequence differences and differential expression between non-allelic copies of TaRr16, are also reported.

Journal Article↗
PubMed2002

An estimation of the minimum number of SSR alleles needed to reveal genetic relationships in wheat varieties. I. Information from large-scale planted varieties and cornerstone breeding parents in Chinese wheat improvement and production.

The genetic relationships of 43 wheat varieties were analyzed with SSR markers. The materials employed included 14 cornerstone breeding parents used before 1980 and another 29 other large-scale planted varieties currently in use in China. A total of 501 different alleles were amplified, including 166 alleles of the A genome, 174 of the B genome and 161 of the D genome. Data obtained were used to estimate genetic similarity using the DICE coefficient, and dendrograms were constructed using the UPGMA method. The dendrogram with 501 alleles successfully differentiated all the cornerstone breeding parents and the large-scale planted varieties, and the dendogram tree was basically consistent with the pedigrees of these varieties. The correlation coefficient between the genetic distance matrix of 501 alleles and that of 450 was 0.99. Correlation coefficients among random samples of alleles suggested that 350 to 400 alleles were needed to detect genetic relationships among common wheat varieties. Correlation coefficients of a genetic similarity matrix based on 580, and those of 501 and 400, random alleles were 0.96 and 0.94, respectively. However, there were marked differences between the matrix based on the 501 alleles and those based on markers located on the A-, B- or D-genome independently. The correlation coefficients between the genetic distance matrix of 501 alleles and alleles within A, B or D genomes were 0.77, 0.76 and 0.67. The estimation of genetic similarity should be based on data from all genomes rather than any one genome.

China↗
PubMed2005

A Kansas wheat harvest: near-fatal asphyxiation with wheat grains.

We present a patient who had a near-fatal asphyxiation with wheat particles. A previously healthy 11-year-old boy slipped into wheat being unloaded from a transport wagon and was immediately submersed. On arrival at the hospital, he was found to have grain impacted in both mainstem bronchi. A combination of flexible and rigid bronchoscopy with optical forceps and Fogarty balloon catheters was successful in clearing the airways. The removal of the particles through the use of small bronchoscopic instruments is a tedious and delicate procedure, but in this case, it resulted in a life saved.

Asphyxia↗
PubMed2005

The reactive oxygen species are involved in resistance responses of wheat to the Russian wheat aphid.

The effect of Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), infestation on the hydrogen peroxide (H(2)O(2)) content and NADPH oxidase (EC 1.6.3.1) activity was studied in the resistant (cv. Tugela DN) and near-isogenic susceptible (cv. Tugela) wheat (Triticum aestivum L.). The objective of this study was to investigate the involvement of the reactive oxygen species (ROS) during the resistance responses against the RWA. Infestation significantly induced an early accumulation of the H(2)O(2) and increase of NADPH oxidase activity to higher levels in the resistant than susceptible plants. Results of inhibitory studies using diphenylene iodonium (DPI), a suicide inhibitor of NADPH oxidase, strongly suggested a possible signalling role for H(2)O(2) during RWA resistance response by activation of downstream defence enzymes [intercellular peroxidase (EC 1.11.1.7) and beta-1,3-glucanase (EC 3.2.1.39)].

Animals↗
PubMed1977

Phosphoglycerate mutase from wheat germ: studies with isotopically labeled 3-phospho-D-glycerates showing that the catalyzed reaction is intramolecular. Appendix: phosphoglycerate mutase from wheat germ: isolation, crystallization, and properties.

The isomerization of 3-phospho-D-glycerate and 2-phospho-D-glycerate catalyzed by the cofactor-independent phosphoglycerate mutase from wheat germ (the isolation and crystallization of which is described in the Appendix) has been shown to be intramolecular by two methods. Mass-spectrometric analysis of the products from the isomerization of a mixture of 3-phospho-D-[2(-2)H]glycerate and 3-[18O]phospho-D-glycerate shows that there is no exchange of labeled phosphoryl group between carbon skeletons in the mutase-catalyzed reaction. Analysis of the products from the isomerization of a mixture of 3-phospho-D-[2(-2)H]glycerate and 3-[32p]phospho-D-glycerate by a method involving the kinetic discrimination between 2(-2)H and 2(-1)H species using the enolase isotope effect similarly shows that the wheat germ phosphoglycerate mutase mediates an intramolecular transfer of the phosphoryl group.

Adenosine Triphosphate↗
PubMed2002

Resistance to wheat streak mosaic virus in transgenic wheat engineered with the viral coat protein gene.

Wheat (Triticum aestivum) plants were stably transformed with the coat protein (CP) gene of wheat streak mosaic virus (WSMV) by the biolistic method. Eleven independently transformed plant lines were obtained and five were analyzed for gene expression and resistance to WSMV. One line showed high resistance to inoculations of two WSMV strains. This line had milder symptoms and lower virus titer than control plants after inoculation. After infection, new growth did not show symptoms. The observed resistance was similar to the 'recovery' type resistance described previously using WSMV NIb transgene and in other systems. This line looked morphologically normal but had an unusually high transgene copy number (approximately 90 copies per 2C homozygous genome). Northern hybridization analysis indicated a high level of degraded CP mRNA expression. However, no coat protein expression was detected.

Biolistics↗
PubMed2004

Responses of female orange wheat Blossom midge, Sitodiplosis mosellana, to wheat panicle volatiles.

Air entrainment samples of volatiles from panicles of intact wheat, Triticum aestivum, cultivar 'Lynx' were collected at the ear emergence/early anthesis growth stage. In an olfactometer bioassay, both freshly cut panicles and an air entrainment sample were found to attract female orange wheat blossom midge adults, Sitodiplosis mosellana. Coupled gas chromatography-electroantennography (GC-EAG) analyses of panicle volatiles located six electrophysiologically active components. These were identified by coupled gas chromatography-mass spectrometry and coinjection with authentic standards, on polar and nonpolar GC columns, as acetophenone, (Z)-3-hexenyl acetate, 3-carene, 2-tridecanone, 2-ethyl-1-hexanol, and 1-octen-3-ol. Although none of these was active when presented individually at the levels present in the entrainment sample, acetophenone, (Z)-3-hexenyl acetate, and 3-carene were active in the olfactometer when presented at a higher dose of 100 ng on filter paper. However, the six-component blend and a blend of acetophenone, (Z)-3-hexenyl acetate, and 3-carene, in the same ratio and concentration as in a natural sample, was as attractive to female S. mosellana as the whole air entrainment sample.

Animals↗
PubMed1995

Differentiation between homoeologous chromosomes 1A of wheat and 1Am of Triticum monococcum and its recognition by the wheat Ph1 locus.

In most allopolyploid plants, only homogenetic chromosome pairing occurs in meiosis, as a result of the recognition of genome differentiation by the genetic system regulating meiotic chromosome pairing. The nature of differentiation between chromosomes of closely related genomes is examined here by investigating recombination between wheat chromosome 1A and the closely related homoeologous chromosome 1Am of Triticum monococcum. The recognition of the differentiation between these chromosomes by the Ph1 locus, which prevents heterogenetic chromosome pairing in wheat, is also investigated. Chromosomes 1A and 1Am are shown to be colinear, and it is concluded that they are differentiated "substructurally." This substructural differentiation is argued to be recognized by the Ph1 locus. In the absence of Ph1, the distribution and frequencies of crossing over between the 1A and 1Am homoeologues were similar to the distribution and frequencies of crossing over between 1A homologues. The cytogenetic and evolutionary significance of these findings is discussed.

Journal Article↗
PubMed2002

Wheat protein composition and properties of wheat glutenin in relation to breadmaking functionality.

The unique breadmaking properties of wheat are generally ascribed to the visco-elastic properties of its gluten proteins. While monomeric gluten proteins (gliadin) show viscous behavior, polymeric gluten proteins (glutenin) are elastic. The unique elasticity of glutenin results to a large extent from its polymeric nature. Glutenin is a highly heterogeneous mixture of polymers consisting of a number of different high- and low-molecular-weight glutenin subunits linked by disulfide bonds. Although glutenin obviously is the major polymeric protein in wheat, other polymeric proteins occur as well. Their importance in breadmaking may be underestimated. Nevertheless, variations in both quantity and quality of glutenin strongly determine variations in breadmaking performance. Structural features of different classes of glutenin subunits are described. Variations in glutenin quality may result from variations in its (1) structure, (2) size distribution, and (3) subunit composition. Some hypotheses on glutenin structure and current insights into the role of glutenin size distribution are evaluated. Finally, different ways in which variation in glutenin composition may directly or indirectly (by affecting glutenin structure and/or size distribution) influence glutenin quality are discussed.

Bread↗
PubMed1993

Influence of the ratio between wheat straw and ground barley, ground corn or dried sugar beet pulp on in sacco dry matter degradation of ryegrass and wheat straw, rumen fermentation and apparent digestibility in sheep.

Castrated male sheep were fed with 5 different rations varying in the straw to concentrate ratio between 100: 0, 75: 25, 50: 50, 25: 75 and 0: 100. Ground barley, ground corn and dried sugar beet pulp were used as concentrate sources. Chopped winter wheat straw was fed as roughage source. All rations were supplemented with a protein-mineral-vitamin-premix. In sacco dry matter degradability of artificially dried ryegrass, untreated and ammonia treated wheat straw was measured within three rumen fistulated sheep. Nylon bags were incubated for 48 h in the rumen of sheep. Volatile fatty acids of rumen fluid were determined by gas chromatography. Samples were taken via rumen fistula 3 h after morning feeding. Apparent digestibility of organic matter and fibre fractions of total rations were determined within five sheep. Increased concentrate portion decreased in sacco dry matter degradability of incubated roughages. Decrease of dry matter degradability was much higher for ammonia treated (from 55.0 to 22.5%) and untreated straw (from 50.9 to 22.7%) than for ryegrass (from 75.6 to 69.2%), when concentrate increased from 0 to 100% of ration. The highest concentrate portions did not show any increase of degradability of ammonia treated straw. Specific concentrate effects were observed when 75 and 100% concentrate were fed (unphysiological level). Ground barley as concentrate source decreased rumen pH to a larger extent (down to 5.18) than corn and sugar beet pulp (down to 5.60 and 5.57). Sheep suffered from rumen acidosis in some cases. Higher concentrate levels increased concentration of total volatile fatty acids of rumen liquid and molar concentration of propionate and butyrate, but decreased acetate. Various concentrate sources showed different influences on parameters of rumen fermentation. Apparent digestibility of organic matter of total rations increased from 52.7 to 86.1% if concentrate portions enhanced from 0 to 100%. High portions of ground barley decreased cellulolytic activity and fibre digestion. On the other hand high levels of sugar beet pulp increased digestibility of crude fibre and neutral detergent fibre.

Animal Feed↗
PubMed1981

The effect of coarse and fine Canadian Red Spring Wheat and French Soft Wheat bran on colonic motility in patients with diverticular disease.

Bran from a Canadian Red Spring Wheat, of both a coarse and fine type, was compared with that from a French Soft Wheat, also with coarse and fine characteristics. The coarse type whether Canadian or French had the more significant effect on the stool weight, speeded the intestinal transit as measured by Hinton markers, and reduced intraluminal pressure in the colon more than did the fine types from the same sources in patients with diverticular disease. The texture of a bran may be important in relationship to its clinical efficacy.

Colon↗
PubMed2002

Effect of wheat enzyme preparation on the performance characteristics of Tom turkeys fed wheat-based rations.

Wheat contains 5 to 8% nonstarch polysaccharides (NSP). The NSP complex forms a viscous mass when fully hydrated, which impedes the absorption of nutrients from chyme and causes reduced growth performance and osmotic diarrhea and associated wet litter. These adverse effects can be alleviated by appropriate enzyme supplementation. The objective of this experiment was to evaluate the efficacy of endoxylanase and beta-glucanase enzyme mixtures supplemented to wheat-based diets on growth performance characteristics of turkeys. Seven-day-old Large White male turkeys were randomly assigned to 40 litter floor pens of 12 poults each as a completely randomized block design arrangement of four experimental treatments and were raised to 140 d. The dietary treatment consisted of a control treatment (no supplemental enzyme) and three dietary enzyme treatments: 1) Lyxasan forte, 2) Natugrain Blend, and 3) Natugrain. Body weight, feed consumption, and mortality were recorded weekly. Feather condition was evaluated at 98 d of age. Natugrain Blend improved BW at 84 d (P < 0.075) and 112 d (P < 0.01) in comparison to the unsupplemented control diet. Lyxasan forte had the best feed/gain ratio throughout the experiment. Subjective feather condition score was significantly improved (P < 0.05) by all the three enzyme treatments and corresponded with reduced incidence of neck and back picking behavior. The enzyme treatment groups had lower mortality than the control group with the Natugrain blend treatment having the lowest mortality rate through the experiment. The results of this experiment demonstrate marginal improvement in growth performance of turkeys depending upon enzyme formulation.

Animals↗