Search Results (34)

With climate change, maintaining wheat quality has become essential for the functional properties, end-use, commodity value, and nutritional benefits of wheat flour. Temperature indirectly influences wheat quality by modulating grain size, starch and protein content, and the balance between these components. This review systematically analyzes temperature-mediated alterations in wheat grain quality, with particular emphasis on the two core components: starch and protein. Specifically, daytime warming generally increases protein content while reducing starch accumulation; however, temperatures exceeding 30 °C diminish key protein quality parameters (UPP%, Glu/Gli ratio, HMW-GS/LMW-GS ratio). Nighttime warming enhances protein quality but compromises starch content and yield potential. Conversely, under low-temperature conditions, starch content declines, whereas protein content is primarily influenced by genotypes and treated temperatures. Furthermore, the underlying mechanisms driving temperature-induced changes in wheat quality traits are discussed. However, the mechanisms of temperature effects have not been fully elucidated, and the results often vary between regions or over years. Thus, identifying conserved high/low-temperature resistance genes, QTLs, epialleles, and epiQTL, as well as developing corresponding molecular markers and epi-markers, is an urgent priority. Meanwhile, genome-editing tools such as CRISPR/Cas could serve as a powerful approach for creating new wheat germplasm with durable high/low-temperature resistance. Full article

Non-satisfactory bread-making quality in wheat, a Tajik staple, hampers food security in Tajikistan and calls for plant breeding efforts. Here, methods were searched for to study grain protein composition, which is of use for Tajik plant breeding to improve bread-making quality. Size-exclusion high-performance liquid chromatography (SE-HPLC) was used to determine protein composition in 22 wheat varieties and breeding lines grown in two locations, which were then compared with the specific protein composition evaluated using electrophoresis and previous results from Tajik breeding and farmer-grown wheat. As Tajik wheat generally showed a large variation in high-molecular-weight glutenin subunit (HMW-GS) composition, with several allelic variants in the same line, single-seed selection was required when using this methodology in breeding for improved bread-making quality, and such an evaluation willalso result in more homogenous lines for protein composition. SE-HPLC was found to be a suitable tool to evaluate protein composition in the current Tajik wheat material with a heterogeneous protein composition, which might be advantageous for adaptation to the local and future climate. However, more easy-to-handle and high-throughput methods, e.g., marker-assisted selection, could be preferable alternatives for studying protein composition in wheat and for use in breeding for increased bread-making quality to increase food security in Tajikistan. Full article

High-molecular-weight glutenin subunits (HMW-GS) are an important component of total cereal proteins in wheat. It is closely related to the processing quality of flour. Here, we analyzed allelic variations at the Glu-1 locus in 163 wheat accessions from Hubei Province, China with SDS-PAGE. Among the 15 alleles detected, alleles 1, 7+8, and 2+12 were the major alleles, and 7, 6+8, and 2+10 were rare alleles. The breeding lines had higher genetic diversity than the commercial varieties. Alleles 7 and 6+8 significantly reduced the grain protein content and wet gluten content of wheat. The “1, 7+9, 5+10” and “1, 14+15, and 2+12” allelic combinations significantly increased the grain protein content, hardness index, test weight, and wet gluten content of wheat. Alleles 7+9, 14+15, and 5+10 were identified as alleles related to high wheat quality. The “1, 7, 5+10”, “1, 6+8, 5+10”, “null, 7+9, 2+12”, “1, 14+15, 2+12”, and “1, 7+9, 5+10” allelic combinations had greater effects on wheat grain quality traits. These results demonstrate the effects of HMW-GS on wheat grain quality traits and provide a reference for the genetic improvement of wheat quality. Full article

Genetic variation in high molecular weight glutenin (HMW-GS) genes is tightly linked with the breadmaking quality of wheat. Hundreds of different alleles have been identified in HMW-GS genes worldwide. Such huge variability makes it difficult to distinguish them using conventional genotyping methods (for example, SDS-PAGE, SNP detection, etc.). Here, we exploited the nanopore amplicon sequencing technique (Amplicon-Seq) to uncover genetic variants distributed along the full-length sequence of six HMW-GSs, including the promoter and protein-coding regions. We analyzed 23 wheat accessions for allelic variants of HMW-GSs using the Amplicon-Seq and SDS-PAGE methods. We obtained sufficient (>50×) target gene coverage by ONT reads in just one hour. Using the obtained data, we identified numerous single nucleotide polymorphisms and InDels in the protein coding and promoter regions. Moreover, Amplicon-Seq allowed for the identification of new alleles (Glu-A1x1-T) of the Glu-1Ax gene that could not be recognized by SDS-PAGE. Collectively, our results showed that Amplicon-Seq is a rapid, multiplexed, and efficient method for high-throughput genotyping of full-length genes in large and complex genomes. This opens new avenues for the assessment of target gene variation to select novel alleles and create unique combinations of desirable traits in plant breeding programs. Full article

The quality of wheat primarily depends on its storage protein quality, especially in regards to gluten content and high-molecular-weight glutenin subunits (HMW-GS). The number of HMW-GS alleles is limited in bread wheat (Triticum aestivum L.), whereas it is abundant in wheat relatives. Therefore, HMW-GS alleles from wheat relatives could provide a potential for improving quality in wheat breeding. Thinopyrum elongatum (EE) is one of the relatives of wheat. The E genome is closely related to the ABD genome in wheat; therefore, Th. elongatum is often used as an excellent exogenous gene donor for wheat genetic improvement. In this study, the high-molecular glutenin subunit gene was cloned and sequenced from Th. elongatum. A specific molecular marker for identifying the Glu-1Ey subunit gene was developed and applied to detected wheat-Th. elongatum alien introgression lines. Quality analysis indicated that the substitution and addition lines containing Th. elongatum alleles significantly (p < 0.05) increased grain protein content by 3.76% to 5.11%, wet-gluten content by 6.55% to 8.73%, flour 8-MW by 0.25% to 6.35%, and bread volume value by 33.77 mL to 246.50 mL, in comparing it with Chinese Spring. The GMP content and lactic acid SRC showed significant positive correlations with flour processing quality and might be used as indicators for wheat quality. The results were expected to provide a novel route for improving processing quality in wheat quality breeding. Full article

The gluten strength and the composition of high- and low-molecular-weight glutenin subunits (HMWGSs and LMWGSs) of fifty-one durum wheat genotypes were evaluated using sodium dodecyl sulfate (SDS) sedimentation testing and SDS polyacrylamide gel electrophoresis (SDS-PAGE). This study examined the allelic variability and the composition of HMWGSs and LMWGSs in T. durum wheat genotypes. SDS-PAGE was proven to be a successful method for identifying HMWGS and LMWGS alleles and their importance in determining the dough quality. The evaluated durum wheat genotypes with HMWGS alleles 7+8, 7+9, 13+16, and 17+18 were highly correlated with improved dough strength. The genotypes containing the LMW-2 allele displayed stronger gluten than those with the LMW-1 allele. The comparative in silico analysis indicated that Glu-A1, Glu-B1, and Glu-B3 possessed a typical primary structure. The study also revealed that the lower content of glutamine, proline, glycine, and tyrosineand the higher content of serine and valine in the Glu-A1 and Glu-B1 glutenin subunits, and the higher cysteine residues in Glu-B1 and lower arginine, isoleucine, and leucine in the Glu-B3 glutenin, are associated with the suitability of durum wheat for pasta making and the suitability of bread wheat with good bread-making quality. The phylogeny analysis reported that both Glu-B1 and Glu-B3 had a closer evolutionary relationship in bread and durum wheat, while the Glu-A1 was highly distinct. The results of the current research may help breeders to manage the quality of durum wheat genotypes by exploiting the allelic variation in glutenin. Computational analysis showed the presence of higher proportions of glutamine, glycine, proline, serine, and tyrosine than the other residues in both HMWGSs and LMWGSs. Thus, durum wheat genotype selection according to the presence of a few protein components effectively distinguishes the strongest from the weakest types of gluten. Full article

Overexpression of Glu-1Bx7 via allele 1Bx7^OE significantly contributes to high dough strength in some wheat varieties and is useful for improving wheat quality. However, the proportion of wheat varieties containing Bx7^OE is quite low. In this study, four cultivars containing 1Bx7^OE were selected, and among the selected varieties, Chisholm (1Ax2*, 1Bx7^OE + 1By8*, and 1Dx5 + 1Dx10) was crossed with Keumkang, a wheat variety that contains 1Bx7 (1Ax2*, 1Bx7 + 1By8, and 1Dx5 + 1Dx10). SDS-PAGE and UPLC analyses showed that the expression of the high-molecular-weight glutenin subunit (HMW-GS) 1Bx7 was significantly higher in NILs (1Ax2*, 1Bx7^OE + 1By8*, and 1Dx5 + 1Dx10) compared with that in Keumkang. Wheat quality was analyzed with near infrared reflectance spectroscopy by measuring the protein content and SDS-sedimentation of NILs. The protein content of NILs (12.94%) was 21.65% higher than that of Chisholm (10.63%) and 4.54% higher than that of Keumkang (12.37%). In addition, the SDS-sedimentation value of NILs (44.29 mL) was 14.97% and 16.44% higher than that of Keumkang (38.52 mL) and Chisholm (38.03 mL), respectively. This study predicts that the quality of domestic wheat can be improved by crossbreeding with 1Bx7^OE-containing cultivars. Full article

Some wheat cultivars show a linear relationship between grain protein concentration (GPC) and baking volume, but others display a saturation curve. Such a saturation curve could be general, but in some cultivars it might only appear at GPC > 17%. However, such GPC is mostly not achieved in the field. Pot experiments with high nitrogen application reliably result in GPC > 17%. In a pot experiment with a high (N1) and an excessive N level (N2) and four cultivars (Akteur, Arnold, Discus and Hystar), the change in grain protein composition and the relationship between different protein fractions and baking volume at GPC > 17% was investigated. GPC ranged from 17 to 24% and mean nitrogen content per grain from 1.2 to 1.8 mg. The N2 treatment increased GPC and mean nitrogen content per grain in the Akteur and Discus cultivar, but not in Arnold and Hystar. N2 increased concentration of gliadin by 10 to 34% and glutenin macropolymer (GMP) in all cultivars by 12 to 73%. Glutenin concentration was increased by N2 in Akteur and Discus (19 to 36%), but was decreased by N2 in the Arnold and Hystar cultivar. Baking volume was moderately increased by N2 in all cultivars by 6 to 9% and correlated significantly with most glutenin fractions in the Akteur and Discus cultivar, with GMP in Arnold and with HMW-GS to LMW-GS ratio in Hystar. Thus, specific effects on grain protein by N2 were responsible for the increased baking volume in each cultivar. However, as gliadin and its sub-fractions hardly correlated with baking volume, a positive effect of increasing gliadin proteins on baking quality was not obvious. Full article

To characterize and compare the protein quality of ten durum wheat genotypes grown under three cropping modalities in Algeria (subhumid in Algiers, subhumid-semiarid in Constantine, and semiarid in Sétif), the protein profile of their kernels was performed by High-Performance Liquid Chromatography (SE-HPLC and RP-HPLC). The “variety” factor has a major impact, mainly on the insoluble fraction (Fi), on the gliadin/glutenin ratio, on the large and small glutenin aggregates (F1 and F2, respectively), and on ω-gliadins and high molecular weight albumins (F3). Conversely, the total protein content and the albumin-globulin fraction (F5) depend mainly on the environment. The α- β- and γ-gliadins (F4) are equally dependent on variety and environment. The subhumid-semiarid agroecological conditions of Constantine (SH-SA) favored an important accumulation of proteins (14.1%), particularly by an increased synthesis of omega gliadins and high-molecular-weight glutenin subunits (HMW-GS), compared to those of Algiers (SH) and Sétif (SA). For these latter environments, metabolic-type proteins are predominant, reflected in a higher F5 fraction (p < 0.05) (albumin and globulin), and significantly more alpha-beta and gamma gliadins. The use of chromatographic analyses to characterize wheat genotypes remains a reliable tool for breeding and variety promotion programs and can provide a better understanding of the ecophysiology of cereal crops. Full article

High molecular weight glutenin subunits (HMW-GSs) play a major role in determining the dough quality of wheat. As the D genome donor of hexaploid wheat, Aegilops tauschii is an important genetic resource for wheat quality breeding. In the present study, a novel HMW-GSs from Ae. tauschii was identified and designated as Glu-D^t1. Multiple sequence alignment indicated that one cysteine was mutated into arginine in the y-type subunit. Site-directed mutagenesis technology was applied to verify the function of gene Glu-D^t1. Three introgression lines (ILs), B9, B25, and B35 with the Glu-D1 loci substituted by Glu-D^t1 were detected from the BC₃F₅ population derived from hexaploid wheat cultivar Jimai22 and Ae. tauschii Y215 through the direct hybridization approach. The dough quality and agronomic performance analysis were performed, which provide valuable resources for wheat genetic studies and breeding for distinctive end-use quality. Full article

The aim of this study was to test the significant effects of inorganic sulfur and cysteine on grain protein and flour quality in wheat and to provide a theoretical basis of wheat cultivation techniques with high yield and quality. In the field experiment, a winter wheat cultivar, Yangmai 16, was used, and five treatments were established, i.e., S₀ (no sulfur fertilizer application during the whole wheat growth period), S(B)₆₀ (60 kg ha⁻¹ inorganic sulfur fertilizer was applied as the basal fertilizer), Cys(B)₆₀ (60 kg ha⁻¹ cysteine sulfur fertilizer was applied as the basal fertilizer), S(J)₆₀ (60 kg ha⁻¹ inorganic sulfur fertilizer was applied as the jointing fertilizer), and Cys(J)₆₀ (60 kg ha⁻¹ cysteine sulfur fertilizer was applied as the jointing fertilizer). The fertilizer application at jointing stage showed a better influence than basal fertilizer application on protein quality; for the content of albumin, gliadin, and high molecular weight glutenin (HMW-GS), Cys(J)₆₀ was the best among these treatments. An increase of 7.9%, 24.4%, 43.5%, 22.7% and 36.4% was found in grain yield, glutenin content, glutenin macro-polymer (GMP), low molecular weight glutenin (LMW-GS), and S content under Cys(J)₆₀, in relation to the control, respectively. A similar trend was found in the end-use quality, as exemplified by an increase of 38.6%, 10.9%, 60.5%, and 109.8% in wet gluten content, dry gluten content, sedimentation volume, and bread-specific volume, respectively; a decrease of 69.3% and 69.1% in bread hardness and bread chewiness was found under Cys(J)₆₀. In terms of application period, topdressing at jointing stage is compared with base fertilizer, the sulfur fertilizer application at jointing stage showed larger effects on grain protein and flour quality, from the different types of sulfur fertilizer, the application of cysteine performed better than the use of inorganic sulfur. The Cys(J)₆₀ exhibited the best effects on protein and flour quality. It was suggested that sufficient sulfur application at jointing stage has the potential to enhance the grain protein and flour quality. Full article

The effect of arbuscular mycorrhizal fungi (AMF) on yield and quality was investigated on a set of seven bread wheat genotypes with varying years of release, including five old genotypes and two modern varieties. A two-year field trial was conducted in central Italy under rainfed conditions. The effect of AM fungal seed coating was proved by assessing the AM fungal root colonization and studied on agronomic and quality traits, and in particular on gluten-forming proteins and grain mineral composition. AMF seed coating led to a general yield improvement in old genotypes (+24%). Concerning the effects on grain quality, while modern genotypes showed an increase in protein content (+16%), in the old ones an improvement of gluten quality was observed, with an increased proportion of HMW-GS from +17% to +92%. The gluten index results were mostly influenced by HMW-GS allelic configuration and amount, showing a significant correlation with gliadin-to-glutenin ratio and HMW-GS to LMW-GS. Concerning mineral uptake, AM fungal treatment determined a general increase in P content, which was more marked in the modern group (+44%). Furthermore, AMF significantly increased mean Fe concentration in Verna (+53%) and Bologna (+45%). Finally, phytate content did not increase with AMF, without affecting mineral bioavailability. Full article

Spelt wheat (Triticum spelta L., 2n=6x=42, AABBDD) is a valuable source of new gene resources for wheat genetic improvement. In the present study, two novel high molecular weight glutenin subunits (HMW-GS) 1Ax2.1* at Glu-A1 and 1By19* at Glu-B1 from German spelt wheat were identified. The encoding genes of both subunits were amplified and cloned by allele-specific PCR (AS-PCR), and the complete sequences of open reading frames (ORF) were obtained. 1Ax2.1* with 2478 bp and 1By19* with 2163 bp encoded 824 and 720 amino acid residues, respectively. Molecular characterization showed that both subunits had a longer repetitive region, and high percentage of α-helices at the N- and C-termini, which are beneficial for forming superior gluten macropolymers. Protein modelling by AlphaFold2 revealed similar three-diamensional (3D) structure features of 1Ax2.1* with two x-type superior quality subunits (1Ax1 and 1Ax2*) and 1By19* with four y-type superior quality subunits (1By16, 1By9, 1By8 and 1By18). Four cysteine residues in the three x-type subunits (1Ax2.1*, 1Ax1 and 1Ax2*) and the cysteine in intermediate repeat region of y-type subunits were not expected to participate in intramolecular disulfide bond formation, but these cysteines might form intermolecular disulfide bonds with other glutenins and gliadins to enhance gluten macropolymer formation. The SNP-based molecular markers for 1Ax2.1* and 1By19* genes were developed, which were verified in different F2 populations and recombination inbred lines (RILs) derived from crossing between spelt wheat and bread wheat cultivars. This study provides data on new glutenin genes and molecular markers for wheat quality improvement. Full article

High-molecular-weight glutenin subunits (HMW-GSs) are important components of gluten, which determine the grain quality of wheat. In this study, we investigated the effects of nitrogen (N) fertilizer application on the synthesis and accumulation of grain protein and gluten quality in wheat lines with different HMW-GSs absent. The results showed that the absence of the HMW-GS in the wheat variety Ningmai 9 significantly decreased the contents of gluten, glutenin macropolymer (GMP), protein compositions, HMW-GS and HMW-GS/LMW-GS. The reduction in glutenins was compensated to some extent by an increase of gliadins. The absence of x-type HMW-GSs (1, 7 and 2 subunits) had a greater effect on gluten and GMP properties than y-type HMW-GSs (8 and 12 subunits). The content of protein compositions, gluten and GMP increased with an increase of N level; however, the increment in wheat lines with the absence of HMW-GS, especially in Ax1a, Bx7a and Dx2a, was lower than that in the wild type under various N levels. The expression level of genes encoding HMW-GSs, and activities of nitrate reductase (NR) and glutamine synthetase (GS), differed significantly among the investigated wheat lines. The reduction in gene expression and activities in Ax1a and Dx2a may account for the reductions in gluten, GMP, protein compositions, HMW-GS and HMW-GS/LMW-GS. Full article

Durum wheat grains (Triticum turgidum L. ssp. durum) are the main source for the production of pasta, bread and a variety of products consumed worldwide. The quality of pasta is mainly defined by the rheological properties of gluten, an elastic network in wheat endosperms formed of gliadins and glutenins. In this study, the allelic variation at five glutenin loci was analysed in 196 durum wheat genotypes. Two loci (Glu-A1 and Glu-B1), encoding for high-molecular-weight glutenin subunits (HMW-GS), and three loci (Glu-B2, Glu-A3 and Glu-B3), encoding for low molecular weight glutenin subunits (LMW-GS), were assessed by SDS-PAGE. The SDS-sedimentation test was used and the grain protein content was evaluated. A total of 32 glutenin subunits and 41 glutenin haplotypes were identified. Four novel alleles were detected. Fifteen haplotypes represented 85.7% of glutenin loci variability. Some haplotypes carrying the 7 + 15 and 7 + 22 banding patterns at Glu-B1 showed a high gluten strength similar to those that carried the 7 + 8 or 6 + 8 alleles. A decreasing trend in grain protein content was observed over the last 85 years. Allelic frequencies at the three main loci (Glu-B1, Glu-A3 and Glu-B3) changed over the 1915–2020 period. Gluten strength increased from 1970 to 2020 coinciding with the allelic changes observed. These results offer valuable information for glutenin haplotype-based selection for use in breeding programs. Full article