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Grain hardness, amylose content, and glutenin subunit composition are critical determinants for end-use properties of wheat. To improve the end-use properties of domestic wheats, we studied these traits between the Australian and North American wheat classes exported to Japan in 2009 and 2011 by analyzing the corresponding alleles. Most hard classes had Pina-D1b or Pinb-D1b. A partial waxy allele (Wx-B1b) was found in all Australian Standard White (ASW) seeds in 2009 and two-thirds of ASW seeds in 2011. All or most American hard wheat seeds had Glu-D1d. Most U.S. Western White (WW) seeds had a null allele (Glu-A1c) or alleles that lacked one of the two Glu-B1 subunits. Most hard red winter (HRW) seeds had Glu-B3b or Glu-B3g. Quality characteristics of these classes seemed to be consistent with these results. In addition, we also found new Glu-1 and Glu-3 alleles in HRW and WW. These results suggested that although there are variations in its allelic composition from year to year, each class has u...

To study the influence of genes from Thinopyrum intermedium on traits affecting the bread-making quality of wheat, two derivatives from a putative disomic addition line in cultivar ‘Vilmorin 27’ were used in cytological, biochemical and molecular characterization. Cytological analysis suggested that one of the derivatives (Line-1) had a terminal deletion involving the long arm of chromosome 1D (2n = 42, Del-1DL”), and the other (Line-2) was a conventional addition line, but also carried the same deletion on chromosome 1D (2n = 44, Thi”+Del-1DL”). Amplification and sequencing of high-molecular-weight glutenin subunit (HMW-GS) genes coded by the Th. intermedium chromosome in Line-2 indicated the presence of one x-type with an extra cysteine and four (rather than one) unique y-type genes. Rheological studies of Line-1 showed significantly lower dough strength compared to ‘Vilmorin 27’, confirming the recognized role of Glu-1D coded HMW-GSs. Line-2 showed significantly higher dough strength compared to the background cultivar, indicating a significant potential of Th. intermedium for improvement of bread-making quality in wheat.

After screening of 177 disomic addition lines (DALs) of wheat (Triticum aestivum) containing a pair of chromosomes from different alien species, we found that the chromosome 1E addition line of Agropyron elongatum, that is known to be a potential genetic resource for drought and salinity tolerance, showed potential for improvement of bread-making quality of wheat. This was indicated by increased SDS sedimentation, specific sedimentation, mixograph peak time and SE-HPLC analysis of polymeric proteins. This addition line spontaneously gave rise to a substitution line for chromosome 1D in subsequent generations that showed weak dough strength. Analysis of the x-type HMW-glutenin subunit sequence of Ag. elongatum from DAL1E indicated that it closely resembled the x-type sequence of the A and B genomes of wheat, and the y-type was intermediate between x- and y-type HMW-glutenin subunit genes. From these observations, it was inferred that 1E-encoded seed storage proteins have considerable potential for improvement of wheat end-product quality if transferred to specific chromosomes such as 1A of Chinese Spring (CS) wheat, which has a negative overall effect on bread-making quality.

This study involved screening of wild species of wheat in search of functionally useful seed storage proteins for improvement of breadmaking quality of wheat (Triticum aestivum). After screening of 177 disomic addition lines (DALs) of wheat belonging to different wild species, Aegilops searsii DALs were selected and studied in detail. These DALs of Ae. searsii were from chromosome 1Ss to 7Ss in the background of cultivated wheat cv. Chinese Spring (CS). By analyzing these addition lines, genetic loci of actively expressed genes for the high molecular weight glutenin subunits (HMW-GS) and gliadin were found on the chromosome 1Ss for the first time and have been designated as Glu-Ss1 and Gli-Ss1, respectively. Disomic addition line of chromosome 1Ss (DAL1Ss) showed improved dough strength in different generations compared with CS. SDS sedimentation value and specific sedimentation of DAL1Ss were higher than CS. Mixograph peak height and band width were higher, with no difference in mixing peak time...

Allelic variation of high molecular weight glutenin subunits (HMW-GS) encoded by Glu-A1, Glu-B1 and Glu-D1 in wheat landraces originating from the Xinjiang Uygur Autonomous District (Xinjiang District) of China was investigated by SDS-PAGE and the relationship between the variation and the winter habit was examined. The most frequent allele at the Glu-A1 locus was Glu-A1c (null allele: 75.5%), followed by Glu-A1b encoding subunit 2* (22.3%). These two alleles were distinctive at Glu-A1 in the landraces of both spring and winter cultivars. No difference in allele frequency was found between the spring and the winter wheat cultivars. At the Glu-B1 locus, the most frequent allele was Glu-B1b (90.8%) encoding subunits 7 + 8, the allele frequency of which was almost the same between the spring and the winter wheat cultivars. Glu-D1a (72.0%) encoding subunits 2 + 12 was a major allele at the Glu-D1 locus among the landraces. Although no cultivar with Glu-d1f encoding subunits 2.2 + 12 was found, the novel subunit pair 2.6 + 12 (24.5%) was observed only in the winter wheat cultivars. Subunit 2.6 was slightly less mobile than subunit 2.2. The major Glu-D1 allele was Glu-D1a (94.5%) among the spring wheat cultivars and this allele characterized the spring wheat cultivars in the Xinjiang District. Both the subunit pair 2.6 + 12 encoded by the Glu-D1bp(t) allele (58.5%) and the subunit pair 2 + 12 encoded by the Glu-D1a allele (40.7%) predominated among the winter wheat cultivars. The large difference in allelic variation at the Glu-D1 locus suggested that the origin of the spring wheat cultivars was different from that of the winter wheat cultivars. The absence of landrace with Glu-D1f suggested that Xinjiang wheat was not related to Japanese wheat.

The production of angiotensin I converting enzyme (ACE) inhibitory peptides by autolysis reactions from wheat milling byproducts was investigated. Milled whole grain, bran, shorts, and red dog acquired ACE inhibitory activity though water soaking treatment. Among the milled fractions, the preparation of shorts exhibited the strongest inhibitory activity (IC50 = 0.08 mg protein/mL) followed by that of bran, red dog, and whole grain in decreasing order. The production of ACE inhibitory peptides was almost completely inhibited by pepstatin A, indicating the contribution of aspartic proteases. The optimal pH for acquiring ACE inhibitory activity of the byproduct fraction (mixtures of bran and shorts) was 3.2. The level of inhibitory activity rose with increasing temperature up to 40 degrees C. The inhibitory activity reached a maximal level after a 12 h reaction time and maintained the same level up to 24 h at 40 degrees C, pH 3.2. From the hydrolysate of the byproduct fraction, six peptides were isolated by several steps of chromatography, and their amino acid sequences were Leu-Gln-Pro, Ile-Gln-Pro, Leu-Arg-Pro, Val-Tyr, Ile-Tyr, and Thr-Phe. Thus, wheat milling byproducts have the possibility to become an effective source for ACE inhibitory peptides.