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PubMed1996

Effects of enhanced O3 and CO2 enrichment on plant characteristics in wheat and corn.

The effects of CO(2) enrichment and O(3) induced stress on wheat (Triticum aestivum L.) and corn (Zea mays L.) were studied in field experiments using open-top chambers to simulate the atmospheric concentrations of these two gases that are predicted to occur during the coming century. The experiments were conducted at Beltsville, MD, during 1991 (wheat and corn) and 1992 (wheat). Crops were grown under charcoal filtered (CF) air or ambient air + 40 nl liter(-1) O(3) (7 h per day, 5 days per week) having ambient CO(2) concentration (350 microl liter(-1) CO(2)) or + 150 microl liter(-1) CO(2) (12 h per day.). Averaged over O(3) treatments, the CO(2)-enriched environment had a positive effect on wheat grain yield (26% in 1991 and 15% in 1992) and dry biomass (15% in 1991 and 9% in 1992). Averaged over CO(2) treatments, high O(3) exposure had a negative impact on wheat grain yield (-15% in 1991 and -11% in 1992) and dry biomass (-11% in 1991 and -9% in 1992). Averaged over CO(2) treatments, high O(3) exposure decreased corn grain yield by 9%. No significant interactive effects were observed for either crop. The results indicated that CO(2) enrichment had a beneficial effect in wheat (C(3) crop) but not in corn (C(4) crop). It is likely that the O(3)-induced stress will be diminished under increased atmospheric CO(2) concentrations; however, maximal benefits in crop production in wheat in response to CO(2) enrichment will not be materialized under concomitant increases in tropospheric O(3) concentration.

Journal Article↗
PubMed2003

Making bread with sourdough improves mineral bioavailability from reconstituted whole wheat flour in rats.

OBJECTIVE: We compared the effects of different kinds of bread fermentation on mineral bioavailability. METHODS: Wistar rats were fed one of the following experimental diets for 21 d: control, reconstituted whole wheat flour (white flour plus bran), yeast bread, and sourdough bread. The apparent mineral absorption and intestinal fermentation were measured in each animal. RESULTS: Phytate contents in yeast and sourdough bread were lower than in reconstituted whole wheat flour (-52% and -71%, respectively). Total cecal pool of short-chain fatty acids, in particular the butyrate pool, was significantly increased by the ingestion of unrefined products. Calcium homeostasis was not modified by these nutritional conditions, whereas magnesium absorption was significantly greater in rats fed the control and sourdough diets than in those consuming whole wheat flour and yeast bread. Magnesium kidney excretion was slightly stimulated by sourdough bread. Compared with the control diet, iron balance was significantly reduced by reconstituted whole wheat flour diet. Yeast bread making counteracted the deleterious effects of whole wheat on iron absorption, whereas sourdough bread making enhanced iron absorption. Further, liver and plasma iron and transferrin saturation levels were lower in rats adapted to the flour diet than in other groups. Zinc absorption was strongly depressed in the presence of unprocessed reconstituted whole wheat flour in the diet, but yeast fermentation afforded a zinc assimilation comparable to the control diet, whereas the sourdough bread led to maximal zinc absorption. Copper absorption increased significantly when rats were fed the sourdough bread, whereas unprocessed whole flour depressed copper absorption (-41% versus control diet). CONCLUSION: Mineral bioavailability from reconstituted whole wheat flour can be improved by bread making. Although yeast fermentation minimizes the unfavorable effects of phytic acid, sourdough bread is a better source of available minerals, especially magnesium, iron, and zinc.

Animals↗
PubMed2002

Biochemical basis for wheat seedling allelopathy on the suppression of annual ryegrass (Lolium rigidum).

The chemical basis for wheat seedling allelopathy on the growth of annual ryegrass was investigated by the identification and quantification of multiple allelochemicals from wheat seedlings. Results indicated that 58 wheat accessions differed significantly in seedling allelopathy and inhibited the root growth of ryegrass from 10 to 91%, depending on accession. Analysis of allelochemicals by GC/MS/MS indicated that allelopathy was significantly correlated with the levels of measured allelochemicals in the shoots and roots of young wheat seedlings. Ryegrass root growth was also negatively correlated with the levels of p-hydroxybenzoic, vanillic, and trans-ferulic acids in root exudates. Wheat allelopathic potential was negatively correlated with the levels of the eight known allelochemicals quantified in the shoots, roots, and water-agar medium, with multiple regression coefficients (r) of -0.61, -0.71, and -0.71, respectively. In comparison with weakly allelopathic accessions, strongly allelopathic accessions produced significantly higher amounts of allelochemicals in the shoots and roots of the wheat seedlings and also exuded larger quantities of allelochemicals into the growth medium. Wheat accessions with strong seedling allelopathy might be useful for management of weeds during the establishment stage, thereby reducing the need for commercial herbicides in early-season application.

Coumaric Acids↗
PubMed2003

Phytotoxic effects of wheat extracts on a herbicide-resistant biotype of annual ryegrass (Lolium rigidum).

Thirty-nine wheat accessions were used to evaluate their extract phytotoxicity against annual ryegrass (Lolium rigidum Gaud.). Aqueous extracts of wheat shoot residues significantly inhibited the germination and root growth of a biotype of annual ryegrass resistant to herbicides of acetyl CoA carboxylase inhibitors (group A), acetolactate synthase inhibitors (B), photosystem II inhibitors (C), and tubulin formation inhibitors (D). The germination of the herbicide resistant (HR) biotype was inhibited by 3-100%, depending upon the wheat accession. The phytotoxic effects on ryegrass root growth ranged from 12% stimulation to 100% inhibition, compared to a control. The germination and root growth of a herbicide-susceptible (HS) biotype of annual ryegrass were also inhibited by the wheat extracts, with germination inhibited by 4-100%, and root growth by 19-100%. Bioassays with two known wheat allelochemicals showed that p-coumaric acid and propionic acid significantly inhibited the growth of both HR and HS biotypes of annual ryegrass. The two compounds completely inhibited the root growth of HR ryegrass at concentrations greater than 5.0 mM. In comparison with p-coumaric acid, propionic acid was more inhibitory to seed germination, shoot, and root growth of both ryegrass biotypes. The root growth of the HR biotype was more sensitive when exposed to wheat extracts, to p-coumaric acid, and to propionic acid. The results suggest that residues of certain wheat cultivars with strong allelopathic potential could provide a nonherbicidal alternative for the management of herbicide-resistant weed species.

Coumaric Acids↗
PubMed2003

Determination of trinexapac in wheat by liquid chromatography-electrospray ionization tandem mass spectrometry.

A quantitative and confirmatory method for the analysis of trinexapac (free acid metabolite of trinexapac-ethyl) in wheat is described. Residues were extracted from wheat with acetonitrile in aqueous phosphate buffer (pH 7) overnight. The extract was directly injected into the HPLC system. Chromatographic separation was achieved on an octadecylsilica column, and detection was performed by negative ion electrospray ionization tandem mass spectrometry. The precursor ion of trinexapac [M - H](-) at m/z 223 was subjected to collisional fragmentation with argon to yield two intense diagnostic product ions at m/z 135 and 179, respectively. Accuracy and specificity for routine analysis of trinexapac were demonstrated. The validated concentration range was 10-200 microg/kg based on a 0.10 g/mL wheat sample extract. Recoveries were within the range of 71-94%, with associated relative standard deviations better than 10%. The limit of detection for trinexapac in wheat was estimated at 5 microg/kg. The method has been applied to a survey of 100 samples of wheat. In 46% of the samples analyzed, a quantifiable amount of trinexapac was detected, ranging from 10 to 110 microg/kg. It has been demonstrated that analyses of trinexapac accurately reflect the total amount of residues of the plant growth regulator, trinexapac-ethyl, in the wheat samples following field application. No residues of the parent compound, trinexapac-ethyl, in wheat were detected.

Chromatography, Liquid↗
PubMed2005

Potential for improving bioavailable zinc in wheat grain (Triticum species) through plant breeding.

A "whole-body" radioassay procedure was used to assess retention and absorption by rats of Zn in mature kernels of whole grain wheat harvested from 28 genotypes (Triticum spp.) grown in nutrient solution supplied with 2 microM ZnSO4 radiolabeled with 65Zn. Grain-Zn concentration differed among genotypes and ranged from 33 to 149 microg g(-1) of dry weight (DW); similarly, grain-Fe concentration varied approximately 4-fold, from 80 to 368 microg g(-1) of DW. Concentrations of Zn and Fe in the grain were positively correlated. Therefore, selecting genotypes high in grain-Zn also tends to increase grain-Fe concentration. Concentrations of myo-inositolhexaphosphate (phytate) in the wheat grain varied from 8.6 to 26.1 micromol g(-1) of DW. Grain intrinsically labeled with 65Zn was incorporated into test meals fed to Zn-depleted rats. All rats readily ate the test meals, so that Zn intake varied directly with grain-Zn concentration. As determined by the percentage of 65Zn absorbed from the test meal, the bioavailability to rats of Zn in the wheat genotypes ranged from about 60 to 82%. The amount of bioavailable Zn (micrograms) in the grain was positively correlated to the amount of Zn accumulated in the grain. There was a significant negative correlation between grain-phytate levels and percentage of Zn absorbed from the wheat grain, but the effect was not large. These results demonstrate that concentrations of Zn in whole-wheat grain, as well as amounts of bioavailable Zn in the grain, can be increased significantly by using traditional plant-breeding programs to select genotypes with high grain-Zn levels. Increasing the amount of Zn in wheat grain through plant-breeding contrivances may contribute significantly to improving the Zn status of individuals dependent on whole grain wheat as a staple food.

Animals↗
PubMed2005

Policosanol contents and compositions of wheat varieties.

Policosanol (PC) is the common name for a mixture of high molecular weight (20-36 carbon) aliphatic primary alcohols, which are constituents of plant epicuticular waxes. Wheat germ oil has been reported to improve human physical fitness, and this effect is attributed to its high PC, specifically its high octacosanol (OC) content. Although the PC composition of wheat leaves has been studied extensively, information on PC content and composition of wheat grain fractions is scarce. The objective of this study was to examine the PC contents and compositions of wheat grain fractions of 31 varieties grown in Oklahoma. PC compositions of the samples were identified using a gas chromatograph coupled with a mass spectrometer. The PC content of wheat bran was higher than that of the germ, shorts, and flour. The Trego and Intrada varieties had the highest PC content among the 31 wheat varieties studied. Tetracosanol (C24), hexacosanol (C26), and OC (C28) were the major PC components in all varieties. This study showed that wheat varieties grown under identical growing conditions and management differ significantly in PC content and composition.

Fatty Alcohols↗
PubMed2000

Degradation of malathion and phenthoate by glutathione reductase in wheat germ.

Residual malathion in wheat was estimated at a lower value when analysis was performed by extraction with acetone after addition of water to swell the wheat, according to the Japanese Bulletin Method. The supernatant of the wheat homogenate showed degradation not only of malathion but also of phenthoate. Malathion and phenthoate were not degraded by the boiled supernatant of the wheat homogenate. It was presumed for this reason that glutathione reductase (GR; EC 1.6. 4.2) in the wheat degraded malathion. The following results were obtained: (1) GR originating in wheat could degrade malathion and phenthoate. (2) The degradation of malathion by the GR was inhibited by excessive GSSG. (3) There was a high correlation between GR activity and malathion degradation activity of the supernatant of wheat homogenates. It is likely that GR acted on the specific structure of malathion and phenthoate, the S=P-S bond, and the blanch structure bonding with the sulfur atom. Following the above, extraction with acetone after addition of water (the Japanese Bulletin Method) should be replaced by extraction with pure organic solvent and without addition of water for swelling.

Biodegradation, Environmental↗
PubMed1998

Developmentally regulated organ-, tissue-, and cell-specific expression of calmodulin genes in common wheat.

Recently, we reported on the characterization of the calmodulin (CaM) gene family in wheat [44]. We classified wheat CaM genes into four subfamilies (SFs) designated SF-1 to SF-4, each representing a series of homoeoallelic loci on the homoeologous chromosomes of the three genomes of common wheat. Here we studied the expression of these wheat CaM genes in the course of wheat development. Northern blot analysis using SF-specific probes revealed differences in SF expression levels in different organs and stages of development. Subsequently, cell-specific expression of CaM SFs was investigated by in situ RNA hybridization. In developing seeds, all CaM SFs showed highest expression in the embryo and less in the aleurone and in the starchy endosperm. In primary roots, all four CaM SFs were expressed in the root cap, meristematic regions and in differentiating cells. During development of the roots, expression gradually decreased. The wheat glutenin gene, which was used as a control throughout our experiments, was found to be expressed in the starchy endosperm but not in the aleurone, embryos or vegetative tissues. In stems, at advanced stages of growth, differences in cell-specific expression of CaM SFs were found. For example, SF-2 was highly expressed in differentiating phloem fibers. Thus, CaM genes in common wheat exhibit a developmentally regulated organ-, tissue-, cell- and SF-specific expression patterns.

Blotting, Northern↗
PubMed2002

Emission of nitrous oxide from rice-wheat systems of Indo-Gangetic plains of India.

Nitrous oxide (N2O) accounts for 5% of the total enhanced greenhouse effect and responsible for the destruction of the stratospheric ozone. The rice-wheat cropping system occupying 26 million ha of productive land in Asia could be a major source of N2O as most of the fertilizer N in this region is consumed by this system. Emission of N2O as influenced by application of urea, urea plus farm yard manure (FYM), and urea plus dicyandiamide (DCD), a nitrification inhibitor, was studied in rice-wheat systems of Indo-Gangetic plains of India. Total emission of N2O-N from the rice-wheat systems varied between 654 g ha(-1) in unfertilized plots and 1,570 g ha(-1) in urea fertilized plots. Application of FYM and DCD reduced emission of N2O-N in rice. The magnitude of reduction was higher with DCD. In wheat also N2O-N emission was reduced by DCD. FYM applied in rice had no residual effect on N2O-N emission in wheat. In rice intermittent wetting and drying condition of soil resulted in higher N2O-N emission than that of saturated soil condition. Treatments with 5 irrigations gave higher emissions in wheat than those with 3 irrigations. In rice-wheat system, typical of a farmer's field in Indo-Gangetic plains, where 240 kg N is generally applied through urea, N2O-N emission is 1,570 g ha(-1) (0.38% of applied N) and application of FYM and DCD reduced it to 1,415 and 1,096 g ha(-1), respectively.

Air Pollutants↗
PubMed2002

Transfer of rye chromosome segments to wheat by a gametocidal system.

A gametocidal chromosome derived from Aegilops triuncialis (3C) induces chromosome mutations in gametes lacking the 3C chromosome in common wheat (Triticum aestivum L.). We combined 3C with chromosome 1R of rye (Secale cereale L.) in a common wheat line to know how efficiently 3C induces transfers of small 1R segments to wheat. In the 811 progeny of this wheat line, we found five wheat chromosomes (2A, 2D, 3D, 5D and 7D) carrying segments of the 1R satellite. Wheat plants carrying these translocations were tested for the presence of a storage protein locus Sec-1 and a cluster of resistance genes for wheat rust diseases, Sr31, Lr26 and Yr9. The 2A and 2D translocations had the Sec-1 and three rust resistance loci. The 3D and 5D translocations had Sr31, Lr26 and Yr9 but not Sec-1. The 7D translocation lacked Sec-1, Lr26 and Yr9, but the presence of Sr31 in this translocation was not determined. This showed that the translocation points fell into three regions of the 1R satellite, namely, proximal to Sec-1, between Sec-1 and the rust resistance loci, and distal to the rust resistance loci. Thus, the 3C gametocidal system was demonstrated to be effective in transferring small rye chromosome segments.

Chromosomes↗
PubMed2000

Food-dependent exercise-induced anaphylaxis: a report of two cases and determination of wheat-gamma-gliadin as the presumptive allergen.

Water/salt-insoluble wheat proteins have been identified as the most frequent allergenic foodstuffs in patients with food-dependent exercise-induced anaphylaxis (FDEIA) in Japan. However, the specific allergenic proteins in wheat-dependent exercise-induced anaphylaxis have not been well defined. Challenge testing, skin testing and a fluoroenzyme immunoassay were used for diagnosis in two patients suspected by history of having wheat-dependent exercise-induced anaphylaxis. Gel chromatography and IgE immunoblotting followed by N-terminal amino acid sequencing were used to identify the allergenic wheat protein. The challenge test revealed that both patients had FDEIA. The skin tests and the immunoassay results suggested that wheat gluten was the allergen in both patients. Gel chromatography of wheat gluten revealed that the antigens had molecular weights ranging from 40 to 250 kDa. IgE immunoblotting and subsequent N-terminal amino acid sequencing revealed that wheat-gamma-gliadin was the antigen predominantly bound by IgE in the two patients.

Adult↗
PubMed2003

The Ph2 pairing homoeologous locus of wheat (Triticum aestivum): identification of candidate meiotic genes using a comparative genetics approach.

Colinearity in gene content and order between rice and closely related grass species has emerged as a powerful tool for gene identification. Using a comparative genetics approach, we have identified the rice genomic region syntenous to the region deleted in the wheat chromosome pairing mutant ph2a, with a view to identifying genes at the Ph2 locus that control meiotic processes. Utilising markers known to reside within the region deleted in ph2a, and data from wheat, barley and rice genetic maps, markers delimiting the region deleted on wheat chromosome 3DS in the ph2a mutant were used to locate the syntenous region on the short arm of rice chromosome 1. A contig of rice genomic sequence was identified from publicly available sequence information and used in blast searches to identify wheat expressed sequence tags (ESTs) exhibiting significant similarity. Southern analysis using a subset of identified wheat ESTs confirmed a syntenous relationship between the rice and wheat genomic regions and defined precisely the extent of the deleted segment in the ph2a mutant. A 6.58-Mb rice contig generated from 60 overlapping rice chromosome 1 P1 artificial chromosome (PAC) clones spanning the syntenous rice region has enabled identification of 218 wheat ESTs putatively located in the region deleted in ph2a. What seems to be a terminal deletion on chromosome 3DS is estimated to be 80 Mb in length. Putative candidate genes that may contribute to the altered meiotic phenotype of ph2a are discussed.

Chromosome Pairing↗
PubMedDate not supplied

Effect of long term feeding of ammoniated wheat straw treated with or without HCl on blood biochemical parameters in growing male buffalo (Bubalus bubalis) calves.

Twenty-four growing male buffalo calves (one year of age; 88.54 +/- 3.81 kg average body weight) were divided into three comparable groups (I, II and III) on the basis of their body weight (BW) in a completely randomised design to study the effect of long term feeding of ammoniated wheat straw (AWS) and hydrochloric acid treated ammoniated wheat straw (HCl-AWS) on blood biochemical changes. The animals were offered a concentrate mixture (CM) along with wheat straw (WS), ammoniated wheat straw (AWS) (4% urea at a 50% moisture level) and hydrochloric acid treated ammoniated wheat straw (HCI-AWS) (4% urea at a 50% moisture level and HCI added to trap 30% of NH3 evolved) in groups I, II and III, respectively for an average daily gain (ADG) of 500 g. All the diets were made iso-nitrogenous by preparing three types of concentrate mixtures of different CP levels. The blood was collected from the jugular vein randomly from three animals of each group initially after 8 months post feeding and subsequently after two months interval up to 14 months of experimental feeding. Due to urea ammoniation, the CP content of WS increased from 3.66 to 8.51 and was further increased to 11.35 due to the addition of HCl during urea-ammoniation of wheat straw. The cumulative period mean plasma glucose values (mg %), in group II (53.13) were significantly (P < 0.001) higher than those in groups I (48.44) and III (50.60). The cumulative period mean values of serum albumin and globulin (g %) were not significantly different and were comparable among the groups I (3.33 and 3.06), II (3.53 and 2.97) and III (3.49 and 2.94). The cumulative period mean values of serum albumin: globulin ratio and total protein values were not significantly different among the different groups. Serum urea and creatinine values were significantly (P < 0.001) higher in group III (58.66 and 2.24) as compared to groups I and II. The cumulative period mean values of serum alkaline phosphatase (ALP) (KA units) did not differ significantly, but serum glutamate pyruvate transaminase (SGPT) and glutamate oxaloacetate transaminase (SGOT) values (units x mL(-1) were significantly (P < 0.001) higher in groups II and III than in group I. The cumulative period mean values of T3 (ng x mL(-1)) did not differ significantly among the groups, but T4 values were significantly (P < 0.001) higher in group III (22.74) than in groups 1 (21.41) and II (20.89), respectively. Since the mean values of all the blood parameters were within the normal range, it may be concluded that feeding of ammoniated wheat straw treated with and without HCl to growing male buffalo calves for fourteen months has no adverse effect on the blood biochemical parameters.

Aging↗
PubMed2005

Natural variation in toxicity of wheat: potential for selection of nontoxic varieties for celiac disease patients.

BACKGROUND & AIMS: Celiac disease (CD) is an intestinal disorder caused by T-cell responses to peptides derived from the gluten proteins present in wheat. Such peptides have been found both in the gliadin and glutenin proteins in gluten. The only cure for CD is a lifelong gluten-free diet. It is unknown, however, if all wheat varieties are equally harmful for patients. We investigated whether wheat varieties exist with a natural low number of T-cell-stimulatory epitopes. METHODS: Gluten proteins present in public databases were analyzed for the presence of T-cell-stimulatory sequences. In addition, wheat accessions from diploid (AA, SS/BB, and DD genomes), tetraploid (AABB), and hexaploid (AABBDD) Triticum species were tested for the presence of T-cell-stimulatory epitopes in gliadins and glutenins by both T-cell and monoclonal antibody-based assays. RESULTS: The database analysis readily identified gluten proteins that lack 1 or more of the known T-cell-stimulatory sequences. Moreover, both the T-cell- and antibody-based assays showed that a large variation exists in the amount of T-cell-stimulatory peptides present in the wheat accessions. CONCLUSIONS: Sufficient genetic variation is present to endeavor the selection of wheat accessions that contain low amounts of T-cell-stimulatory sequences. Such materials may be used to select and breed wheat varieties suitable for consumption by CD patients, contributing to a well-balanced diet and an increase in their quality of life. Such varieties also may be useful for disease prevention in individuals at risk.

Celiac Disease↗
PubMed2003

Map-based isolation of the leaf rust disease resistance gene Lr10 from the hexaploid wheat (Triticum aestivum L.) genome.

More than 50 leaf rust resistance (Lr) genes against the fungal pathogen Puccinia triticina have been identified in the wheat gene pool, and a large number of them have been extensively used in breeding. Of the 50 Lr genes, all are known only from their phenotype and/or map position except for Lr21, which was cloned recently. For many years, the problems of molecular work in the large (1.6 x 10(10) bp), highly repetitive (80%), and hexaploid bread wheat (Triticum aestivum L.) genome have hampered map-based cloning. Here, we report the isolation of the Lr gene Lr10 from hexaploid wheat by using a combination of subgenome map-based cloning and haplotype studies in the genus Triticum. Lr10 is a single-copy gene on chromosome 1AS. It encodes a CC-NBS-LRR type of protein with an N-terminal domain, which is under diversifying selection. When overexpressed in transgenic wheat plants, Lr10 confers enhanced resistance to leaf rust. Lr10 has similarities to RPM1 in Arabidopsis thaliana and to resistance gene analogs in rice and barley, but is not closely related to other wheat Lr genes based on Southern analysis. We conclude that map-based cloning of genes of agronomic importance in hexaploid wheat is now feasible, opening perspectives for molecular bread wheat improvement trough transgenic strategies and diagnostic allele detection.

Alleles↗
PubMed1988

Expression of modified rye ribosomal RNA genes in wheat.

Several wheats (Triticum aestivum L. em Thell.) containing the short arm of chromosome 1R from rye (Secale cereale L.) translocated to the long arm of wheat chromosome 1B were examined, by in situ hybridization with a biotinylated probe, for the expression of rye rRNA genes located in the nucleolus-organizing region (NOR) present on the short arm of 1R. The wheats analyzed contain a reduced rye NOR band, identified by a C-banding technique, that was assumed to have resulted from a deletion that reduced the number of rRNA genes and spacer units. Genes being actively transcribed could be recognized as dispersed label on DNA within the nucleolus, while those genes that were inactive were seen as condensed label. After in situ hybridization with a biotinylated rye NOR spacer probe, no evidence of rye rRNA gene activity was detected in the plants containing a reduced rye NOR band. Biotin-labeling of chromosomes containing a normal-sized rye NOR locus showed a degree of rye activity consistent with the results of a previous study that used a radioactive probe detected by autoradiography. It was determined previously that rye rRNA genes in a wheat background show significantly less activity than in diploid rye because the spacer units between the rRNA genes of rye are smaller than those of wheat, and in cereals the ribosomal locus with the larger spacer unit is preferentially transcribed. The present results indicate that the number of spacer units is also important in determining which NOR locus (i.e., rye or wheat) will be expressed when several ribosomal loci are present in a wheat background.

Journal Article↗
PubMed1997

Wheat cytosolic acetyl-CoA carboxylase complements an ACC1 null mutation in yeast.

Spores harboring an ACC1 deletion derived from a diploid Saccharomyces cerevisiae strain, in which one copy of the entire ACC1 gene is replaced with a LEU2 cassette, fail to grow. A chimeric gene consisting of the yeast GAL10 promoter, yeast ACC1 leader, wheat cytosolic acetyl-CoA carboxylase (ACCase) cDNA, and yeast ACC1 3' tail was used to complement a yeast ACC1 mutation. The complementation demonstrates that active wheat ACCase can be produced in yeast. At low concentrations of galactose, the activity of the "wheat gene" driven by the GAL10 promoter is low and ACCase becomes limiting for growth, a condition expected to enhance transgenic yeast sensitivity to wheat ACCase-specific inhibitors. An aryloxyphenoxypropionate and two cyclohexanediones do not inhibit growth of haploid yeast strains containing the yeast ACC1 gene, but one cyclohexanedione inhibits growth of the gene-replacement strains at concentrations below 0.2 mM. In vitro, the activity of wheat cytosolic ACCase produced by the gene-replacement yeast strain is inhibited by haloxyfop and cethoxydim at concentrations above 0.02 mM. The activity of yeast ACCase is less affected. The wheat plastid ACCase in wheat germ extract is inhibited by all three herbicides at concentrations below 0.02 mM. Yeast gene-replacement strains will provide a convenient system for the study of plant ACCases.

Journal Article↗