Comparative Studies of HighMrSubunits of Rye and Wheat. I. Isolation and Biochemical Characterisation and Effects on Gluten Extensibility

The structural features of highM_rglutenin subunits of wheat were compared with those of analogous proteins from rye. Subunits of two rye cultivars (Danko and Halo) and of the wheat cultivar Rektor were isolated from defatted flours by extraction with 50% (v/v) aqueous propan-1-ol under reducing conditions at 60°C followed by precipitation using a 60% concentration of propan-1-ol. The yields of dialysed and freeze-dried subunits were 0·33% and 0·32% (w/w of flour), respectively (rye cultivars), and 0·91% (Rektor). SDS–PAGE revealed that the rye cultivars contained at least five subunits with mobilities corresponding to the x-type subunits of wheat. Separation by RP–HPLC indicated that the rye cultivars did not differ in the qualitative composition of subunits, but in their quantitative proportions. The surface hydrophobicities of the rye subunits were significantly lower than those of wheat subunits. The amino acid compositions of single rye subunits were characterised by high contents of Glx, Gly and Pro, and they were closely related to those of wheat subunits, except that the Glx content was generally lower and the Cys content higher. Notable differences between rye and wheat subunits were found in their contributions to gluten strength. Whereas wheat subunits, reoxidised with potassium bromate and mixed with a standard wheat flour, caused a significant increase in gluten strength, reoxidised rye subunits had the opposite effect.     

Influence of chemical and biological treatments on volatile oil composition of Artemisia annua Linn.

The relative abundance of isoprenoids and other volatile components in the aerial parts of Artemisia annua Linn. (Asteraceae) after different nutritional treatments was analyzed by GC and GC/MS. Hydro-distillation of untreated (control) plants yielded 0.28 ± 0.04% essential oil on fresh weight basis. Monoterpenes were predominant in the essential oil of which cis-limonene-1,2-epoxide (22.1%), artemisia ketone (11.5%), iso-pinocamphone (11.4%), thujyl alcohol (9.9%) and camphor (8.4%) were the major components. The essential oil distilled from A. annua treated with Azospirillum (2 ml/plant) amounted to 0.30 ± 0.03% of fresh weight and consisted mainly of neral (31.1%), β-caryophyllene (25.1%), artemisia ketone (10.0%), thujyl alcohol (9.4%), trans-bergamotene (8.5%) and spathulenol (4.8%). The essential oil from plants treated with basal N, P, K and S application (in the form of urea P₂O₅, K₂O and gypsum at a rate of 120, 50, 100 and 50 kg/ha, respectively) amounted to 0.32 ± 0.03% of fresh weight and consisted mainly of thujyl alcohol (33.3%), β-caryophyllene (15.5%), cis-undec-5-ene (14.4%), artemisia ketone (6.0%), trans-nerolidol (5.8%) and undec-4-ene (4.6%). The hydrodistillation of A. annua treated with Glomus (Mycorrhizal soil 50 g/plant) yielded 0.50 ± 0.02% essential oil on fresh weight basis. The sesquiterpenes were predominant in this essential oil and consisted of β-caryophyllene (51.2%), trans-bergamotene (15.4%), α-gurjunene (14.3%), germacrene D (5.1%) and ledol (4.5%) as major components. The only monoterpenes in the essential oil were neral, nerol and pulegone (each less than 1%). These findings suggest that A. annua treated with Glomus lacks glandular trichomes—the primary sites of synthesis of monoterpenes.     

Differences in conformational stability of barley alpha-amylase isozymes 1 and 2. Role of charged groups and isozyme 2 specific salt-bridges

Barley alpha-amylase isozymes 1 (AMY1) and 2 (AMY2) have 80% sequence identity but possess different physico-chemical properties. By incubation in the range 37–85 °C T₅₀ is 75.2 °C of AMY1 and 79.2 °C of AMY2. While AMY2 is also most stable in urea at pH 6.7, [urea]₅₀ being 8.2 M compared to 7.9 M for AMY1, AMY1 has highest stability in urea below pH 6 or in the presence of NaCl. Moreover AMY1 is most stable in guanidinium chloride. Charge screening thus destabilises AMY2 but stabilises AMY1. Isozyme sequence comparison suggests that AMY1 lacks four of the 20 salt-bridges identified in the crystal structure of AMY2. The four residues that differ comprise Lys67_AMY2 and Asp267_AMY2, forming salt-bridges on the surface of the catalytic (β/α)₈-barrel (domain A), and Glu96_AMY2 and His344_AMY2 that participate in charged networks between domain A and the small domain B and the C-terminal domain, respectively. Four corresponding AMY2 mimics A68K; D97E; Q269D; N346H were made in AMY1 by site-directed mutagenesis. While D97E and Q269D have slightly improved stability compared to AMY1 wild-type, N346H and, under certain conditions, A68K are destabilised. The four mutants show 22–176% activity (k_cat/K_m) toward 2-chloro-4-nitrophenol β- -maltoheptaoside and amylose DP17 and 43–117% activity for insoluble starch.     

Hydrothermal Processing of Barley (cv. Blenheim): Optimisation of Phytate Degradation and Increase of FreeMyo-inositol

Optimal conditions were developed for hydrothermal processing of whole barley kernels (cv. Blenheim) to degrade phytate (myo-inositol hexaphosphate) and to increase the content of freemyo-inositol. The hydrothermal treatment comprised of two wet steeps, where lactic acid solution of different concentrations was used, and two dry steeps followed by successive drying. Experiments were performed as a central composite design and evaluated by multiple linear regression. The variables in the experiments were temperature in the first wet and dry steep (T₁), temperature in the second wet and dry steep (T₂) and lactic acid solution concentration in both wet steeps (C) and mathematical models were developed in these variables. Optimal conditions for maximal phytate degradation and for maximal increase of freemyo-inositol wereT₁=48 °C,T₂=48–50 °C andC=0·8%, at these conditions the amount of phytate was reduced by 95–96% and the freemyo-inositol concentration was increased from 0·56 to 2·45 μmol/g d.m. We conclude that this hydrothermal process can be used to produce a barley product (cv. Blenheim) with a low phytate content and a high level of freemyo-inositol.     

Fortification of sulfited tannin from the bark of Acacia mangium with phenol–formaldehyde for use as plywood adhesive

The Acacia mangium tree contains 10% bark (v/v), of which about 20% are extractives. Extraction of this bark using a combination of water and sulfite medium can produce between 15% and 25% tannin materials (dry weight). In this work, several extraction conditions such as bark size, plantation site, extraction time and extraction medium were studied. The results showed that by using either hot water or a sulfite medium, a reasonable amount of tannin yield can be obtained. Bark size of less than 1-mm mesh size gave relatively high tannin yield irrespectively of the extraction medium used. Using a 600:100:2:0.5 (w/w) ratio of water:bark:sodium sulfite:sodium carbonate, and reacted at 75 °C for 3 h improved the tannin yield by at least 30%. The extracts were reasonably reactive towards formaldehyde as shown by their high Stiasny number; water extract, 60–70% and aqueous sulfite–carbonate extracts, 85–90%. The gluing results showed that the shear strength of the plywood can meet the requirements of the European Standards EN 314-1 and EN 314-2:1993. Incorporation of low molecular weight PF resin (10 parts) and PF (10 parts) improved the shear strength from 0.96 MPa to 1.43 MPa after a 72 h boiling test. This study showed that A. mangium tannin blended with commercial plywood phenol–formaldehyde resin, low molecular weight PF and paraformaldehyde as a cross-linker can be used to bond Kedondong (Canarium spp.) wood veneers suitable for both interior and exterior grade plywood.     

Yield formation of CO2-enriched hybrid rice cultivar Shanyou 63 under fully open-air field conditions

Hybrid indica rice (Oryza sativa L.) cultivars play an important role in rice production system due to its heterosis, resistance to environmental stress, large panicle and high yield potential. However, no attention has been given to its yield responses to rising atmospheric [CO₂] in conjunction with nitrogen (N) availability. Therefore we conducted a free air CO₂ enrichment (FACE) experiment at Yangzhou, Jiangsu, China (119°42′0′′E, 32°35′5′′N), in 2004–2006. A three-line hybrid indica rice cv. Shanyou 63 was grown at ambient and elevated (ca. 570 μmol mol⁻¹) [CO₂] under two levels of supplemental N (12.5 g Nm⁻² and 25 g Nm⁻²). Elevated [CO₂] had no effect on phenology, but substantially enhanced grain yield (+34%). The magnitude of yield response to [CO₂] was independent of N fertilization, but varied among different years. On average, elevated [CO₂] increased the panicle number per square meter by 10%, due to an increase in maximum tiller number under enrich [CO₂], while productive tiller ratio remained unaffected. Spikelet number per panicle also showed an average increase of 10% due to elevated [CO₂], which was supported by increased plant height and stem dry weight per tiller. Meanwhile, elevated [CO₂] caused a significant enhancement in both filled spikelet percentage (+5%) and individual grain weight (+4%). Compared with the two prior FACE studies on rice, hybrid indica rice cultivar appears to profit much more from elevated [CO₂] than japonica rice cultivar (ca. +13%), not only due to its stronger sink generation, but also enhanced capacity to utilize the carbon sources in a high [CO₂] environment. The above data has significant implication with respect to N strategies and cultivar selection under projected future [CO₂] levels.     

Antioxidant and Immunity Activity of Water Extract and Crude Polysaccharide from <Emphasis Type="Italic">Ficus carica</Emphasis> L. Fruit

The antioxidative activities of water extract (WE) and crude hot-water soluble polysaccharide (PS) from Ficus carica L. fruit were investigated using various assays in vitro, including scavenging abilities on DPPH, superoxide and hydroxyl radicals and reducing power. The immunity activities of PS were evaluated using the carbon clearance test and serum hemolysin analysis in mice. In addition, total phenolics and flavonoids contents were also determined. Both WE and PS have notable scavenging activities on DPPH with the EC₅₀ values of 0.72 and 0.61 mg/ml, respectively. The PS showed higher scavenging activity than WE on superoxide radical (EC₅₀, 0.95 mg/ml) and hydroxyl anion radical (scavenging rate 43.4% at concentration of 4 mg/ml). The PS (500 mg/kg) also has a significant increase in the clearance rate of carbon particles and serum hemolysin level of normal mice. The results indicate that both WE and PS might be applicable in healthy medicine and food industry.     

Some observations on the toxic effects of the seed extract ofSphenostylis stenocarpa (Hochst ex A. Rich) Harms. on intestinal muscle

The effects of the water extract ofSphenostylis stenocarpa were observed on the guinea pig ileum and rabbit jejunum. The extract produced dose dependent — contractions of the guinea pig ileum with an ED₅₀ of 3.664×10^–5 g/ml and a calculated dose ratio of 1.25. The extract specifically stimulated muscarine receptors. Atropine (8×10^–7 g/ml) caused a parallel shift to the right of the log dose — response curve in the guinea pig ileum suggesting a competitive antagonism. Boiling for about 12 h did not affect the contractile action of the extract on tissue preparations. However, boiling for 12–14 h completely abolished its contractile effect. Incubation of the extract with cholinestrerase at 37°C for 1 h did not abolish its contractile action on the intestine.     

Biological Properties of Fucoxanthin in Oil Recovered from Two Brown Seaweeds Using Supercritical CO2 Extraction

The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO₂ (SC-CO₂) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO₂ method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO₂ (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO₂ oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO₂. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO₂ extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.     

Valorization of three varieties of grape

In the present investigation, seed methanolic extracts of three Vitis vinifera (Muscat d’Italie, Syrah and Carignan) were assayed for their antioxidant activities. Results showed that there are strong variations in the contents of total phenols (440.97–121.94 mg GAE g⁻¹ DW), flavonoids (48.07–16.81 mg EC g⁻¹ DW) and tanins (37.15–14.9 mg EC g⁻¹ DW) from the studied seeds. The phenolic composition of these extracts was determined by RP–HPLC after acid hydrolysis. The main phenolic compound was quercetin with 27.2% in Muscat d’Italie, 48.8% in Syrah and 28.4% in Carignan. Besides, all seed extracts showed remarkable DPPH radical scavenging activity with IC₅₀ values ranged from 1.8 to 30 μg ml⁻¹. EC₅₀ values of reducing power activity ranged from 100 to 120 μg ml⁻¹. The high phenolic content and the considerable antioxidant activities of vitis seed extracts could potentially be considered as an expensive source of natural antioxidants.     

Larvicidal property of essential oils against Culex quinquefasciatus Say (Diptera: Culicidae)

Essential oils from 22 aromatic plant species were tested for mortality of the mosquito larvae Culex quinquefasciatus. Lethal concentrations were determined for individual essential oils. Essential oils obtained from Thymus vulgaris, Satureja hortensis and Thymus satureioides plants showed the highest effect, with LC₅₀ found lower than 50 μg/ml (33, 36 and 44 μg/ml, respectively). Analyses showed that majority substances for T. vulgaris were thymol and p-cymene (60.3 and 10.1%, respectively); carvacrol and γ-terpinene for S. hortensis (48.1 and 36.7%, respectively), and borneol and thymol for T. satureioides (30.3 and 32.5%, respectively).The selected essential oils also showed very good effectiveness with respect to mortality and percentage of adult emergence upon short-term exposure in water contaminated with lethal doses of individual oils. While there was 77% adult emergence from the larvae in the control, in T. vulgaris, T. satureoides and S. hortensis there was only 12.3, 15.3 and 16.0% adult emergence, respectively. High antioviposition effectiveness was found in all selected oils. Almost 100% deterrence of female oviposition was determined for all oils in concentrations of 0.02%. Significant differences were seen with tested concentrations of 0.01 and 0.005%, where the oil of T. vulgaris proved most effective (repellency about 99.8 and 62.3%, respectively).     

农杆菌介导法将抗草甘膦基因转入玉米自交系

利用农杆菌介导法将抗草甘膦基因(ssu-G₂-aroA)转入优良玉米自交系R18-599和齐319,侵染后的愈伤组织转至潮霉素浓度为10 mg/L的筛选培养基上,继代筛选3轮,每轮3周;得到的抗性愈伤组织在含有潮霉素浓度为3 mg/L的分化培养基上进行分化,R18-599获得30株再生植株,齐319获得18株再生植株。经PCR鉴定后共得到7株转化抗性植株(4株R18-599、3株齐319)。经PCR-Southern及RT-PCR检测结果表明,ssu-G₂-aroA基因已稳定整合到了玉米基因组中,并在RNA水平上得到表达。     

Prior weakening of Macrophomina phaseolina and Fusarium propagules for enhancing efficiency of Brassica amendments

In a two year field study, the effect of varying intensities of sub-lethal heating on the efficiency of Brassica amendments in controlling viable populations of Macrophomina phaseolina and Fusarium oxysporum f sp. cumini was determined in an arid region of India. After 30 d of dry summer exposure of pathogen infested soil, incorporation of mustard residues and oil cake (0.18% and 0.04% w/w) and then applying one irrigation caused significant reduction by 75.3–81.3% in viable counts of M. phaseolina that causes dry root rot of legumes and by 93.9% in counts of F.o. f. sp. cumini causing wilt of cumin (Cuminum cyminum L.) at 0–15 and 16–30 cm depths. Increasing duration of summer exposure to 60 d improved the reductions in viable propagules of M. phaseolina by 83.6–90.4% and in F.o. f. sp. cumini by 78.2–94.8% at same soil depths. At certain heat levels, reduction in viable population of Fusarium due to amendments and irrigation was greater than that recorded in Macrophomina. Significantly low levels of reduction in pathogenic propagules of Macrophomina (63.9–71.4%) and Fusarium (48.0–57.2%) under shade compared to unshaded conditions indicated that mild heating did not cause discernible weakening effect. In second season also, 89.2–91.5% and 78.5–95.8% reduction in counts of Macrophomina and Fusarium, respectively was achieved by the application of amendments after 60 d of summer exposure at 0–30 cm soil depth. These results suggested a new approach to improve the control of soil-borne plant pathogens in hot arid regions by combining prolonged sub-lethal heating, effective naturally available on-farm wastes as soil amendments and one summer irrigation.     

The quality of tomato for canning as affected by combined chloride,nitrate and osmotic potential of the nutrient solution

The quality of tomato fruit and juice (Lycopersicon esculentum L. cv. VF M82-1-8) grown in an aerohydroponic system in a greenhouse was affected by the level of Cl^– and NO ₃ ^– , and by the osrnotic potential (OP) of the nutrient solutions. The total suspended solids (degrees Brix) in the fresh juice increased from approximately 4.0 in the nonsaline solutions (OP –0.05 MPa) to approximately 5.6–5.8 in the saline solutions (OP –0.45 MPa). Juice acidity was similarly affected by the Cl^–, NO ₃ ^– and OP levels in the nutrient solutions. Less affected, the ascorbic acid content of juice, was lowest ( 8–9 mg/100 cc) in the high-NO ₃ ^– -nonsaline solution treatments, and was between 10 and 12 mg/100 cc at OP levels greater than –0.2 MPa. NO ₃ ^– in the juice was high ( 60 mg/L) under low OP conditions ( –0.05 to –0.1 MPa), especially when combined with high NO ₃ ^– levels, and lower (between 8 and 30 mg/L) in plants exposed to saline conditions (low OP). Fruit puffiness (boxiness) was reduced markedly by salinity and was not considerably affected by the NO ₃ ^– /Cl^– ratio, while fruit firmness was influenced by both factors.Contribution from the Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan, Israel.     

Antioxidative and Antigenotoxic Activity of Extracts from Cosmos (Cosmos bipinnatus) Flowers

The Cosmos bipinnatus has been used in a traditional herbal remedy for various diseases such as jaundice, intermittent fever, and splenomegaly. The present study describes the preliminary evaluation of antioxidant activities and antigenotoxic effect of Cosmos bipinnatus flowers according to four different colors (white, pink, orange, and violet). The antioxidants properties were evaluated by determining TPC, DPPH RSA, ABTS RSA, and RP. The highest TPC of methanolic CFE (at concentration of 1 mg/ml) showed in violet colored CF (1,013 μM), and IC₅₀ of DPPH RSA, ABTS RSA, and RP were also the lowest in violet colored CFE with values of 0.61, 1.48, and 0.82 mg/ml, respectively. The antigenotoxic effect of the CFE on DNA damage induced by H₂O₂ in human leukocytes was evaluated by Comet assay. Pretreatments with CFE produced significant reductions in oxidative DNA damage at the concentration of 500 μg/ml, except for violet colored CFE. The ED₅₀ value of white colored CFE has shown the highest inhibition (0.40 mg/ml) on H₂O₂ induced DNA damage, followed by orange > pink > violet color. These results suggested that Cosmos bipinnatus has significant antioxidant activity and protective effect against oxidative DNA damage.     

Study of the effect of hydrothermal process conditions on pasta quality

The effect of hydrothermal treatment on the pasting, hydration properties and colour quality of commercial fresh pasta were studied following an Instantaneous Controlled Pressure Drop treatment. This hydrothermal procedure involves a physical modification at high temperature (<144 °C) and restricted moisture content (<30%) during a very short time (15–40 s) followed by a rapid pressure drop to a vacuum (50 mbar). Two process variables (steam pressure level and processing time) were investigated using response surface methodology. Steam pressure level had the greatest effect on hydration and pasting parameters. Increased pressure resulted in elevation of mass ratio between cooked and uncooked pasta (W_i/W₀)_{100 °C} and reduction of for all treated pasta. The optimum cooking time of untreated pasta was 7 min (W/W₀=2.4), whereas for the same ratio it was less than 1 min for pasta treated at pressures ranging between 2.5 and 3.5 bar. The viscosity at 10 min (V₁₀) increased linearly when the pressure level increased. V₁₀ was 146 cP for untreated pasta whereas it reached 2659 cP for pasta treated at 3.9 bar (144 °C) for 25 s. The cold paste viscosity and setback viscosity decreased when the pressure varied from 1 to 3.9 bar.     

The Role of Dextrins in the Stickiness of Bread Crumb made from Pre-Harvest Sprouted Wheat or Flour Containing ExogenousAlpha-Amylase

Dextrins were extracted in water from bread made from pre-harvest sprouted wheat or standard flour supplemented with exogenousalpha-amylases. The dextrins were separated by gel permeation chromatography and the dextrin content (% of crumb weight) determined for different degree of polymerisation (DP) size classes; DP 1–2, DP 3–10, DP 11–50, DP 51–200 and DP >200. There were significant correlations between the dextrin content in each size class and crumb stickiness (r=0·84–0·91, 22 df ). The most significant correlation (r=0·96) was between total dextrin content and crumb stickiness. Addition of dextrins of various DP ranges from various sources to standard flour produced bread with sticky crumb. Again, the degree of stickiness was generally related to the amount of total dextrin in the crumb and not to size distribution of dextrins. In this instance, extensive enzymic hydrolysis of starch was not necessary to produce sticky crumb; the dextrins caused crumb stickiness directly. Addition of dextrins to reconstituted gluten–starch flour produced bread with unexpectedly low dextrin levels and correspondingly low stickiness scores. It is concluded that, to produce sticky crumb, high levels of dextrin of any size are necessary in the crumb; a sticky mass is produced when dextrins dissolve in the excess «free» water that is normally «bound» to starch, gluten and other insoluble components of bread crumb.     

In vitro antioxidant activity of ragweed (Ambrosia artemisiifolia L., Asteraceae) herb

The antioxidant activity in 70% aqueous acetone extracts of the herb of Ambrosia artemisiifolia L., Asteraceae was evaluated with regards to total polyphenol and flavonoid contents. Antioxidant activity has been assessed by two commonly used in vitro tests, based on determination of ferric-reducing antioxidant power (FRAP assay) and DPPH free radical scavenging ability (DPPH assay), against butylated hydroxytoluene (BHT), ascorbic acid and quercetin, which were used as positive control substances. The results of both antioxidant tests showed that the plant material expressed a considerable activity (DPPH IC₅₀ = 27.6 μg/ml; FRAP value = 2.37 mmol Fe²⁺/g), attributed to both flavonoid aglyca and resembling glycosides, as verified by dot-blot TLC analysis.     

Efficacy of Rheum officinale liquid formulation on cucumber powdery mildew

Rheum officinale liquid formulation, the ethanol extract from roots of R. officinale Baill., formulated as physcion 5 g l⁻¹ aqueous solution (AS), has been commercialized in China for controlling cucumber powdery mildew (Podosphaera xanthii (Castagne) U. Braun & Shishkoff). The efficacy of the product was evaluated in pot tests under controlled conditions and in open and protected fields in China over 2 years. In most trials, the efficacy reached above 80% at the rates of 10–50 mg a.i l⁻¹ water after three applications and at the rates of 20–50 mg a.i l⁻¹ water after two applications. The cucumber fruit yield in the product treatment was as many or more as triadimefon treatment, and over 53.1% compared to the untreated control. These results showed that Chinese rhubarb extract could be an effective alternative plant protecting agent in the integrated and biological management of cucumber powdery mildew.     

Detection of y-type Subunit at theGlu-A1Locus in Some Swedish Bread Wheat Lines

Electrophoretic and reversed phase high performance liquid chromatographic (RP–HPLC) analyses were performed on gluten proteins extracted from flours milled from two different Swedish bread wheat lines; these lines have been reported to possess a novel highM_rglutenin subunit controlled by a gene at theGlu-A1locus, referred to as 21*. Although RP–HPLC indicated that subunit 21* has a surface hydrophobocity similar to that of the commonly occurring allelic subunits 1 or 2*, it differs from them in isoelectric point, being more basic when analysed by two dimensional gel electrophoresis (IEF/SDS–PAGE). RP–HPLC separations of highM_rglutenin subunits showed the presence of an additional peak, the behaviour of which was similar to that of y-type subunits encoded by genes at theGlu-A1ylocus and present only in wild wheatsT. urartu(AA) orT. dicoccoides(AABB). Based on chromatographic results and on the tight linkage observed with subunit 21*, it is suggested that the additional component (indicated as 21*y), present in the breeding lines analysed, corresponds to the y-type subunit encoded at theGlu-A1locus. Genes encoding the subunits 21* and 21*y were also analysed by polymerase chain reaction (PCR). Contrary to what was observed for the polypeptide itself, the gene corresponding to subunit 21* was similar in size to that encoding subunit 2* and shorter than that corresponding to subunit 1. Moreover, the amplification product corresponding to the active 21*y gene was shorter than that of the allelic inactive gene present in the bread wheat cultivar Cheyenne. As reported for other highM_rglutenin subunits, gene size differences observed were due to a different length of the repetitive region. Because cultivated polyploid wheats have been shown to have only the x-type subunit at theGlu-A1locus, it is speculated that the new combination, with both x- and y-type subunits expressed, might have been introgressed during breeding processes from the wild wheat progenitorsT. urartuorT. dicoccoides, which have genotypes expressing both types of subunits.