TaNAC100 acts as an integrator of seed protein and starch synthesis exerting pleiotropic effects on agronomic traits in wheat.

High-molecular-weight glutenin subunits (HMW-GS) are major components of seed storage proteins (SSPs) and largely determine the processing properties of wheat (Triticum aestivum) flour. HMW-GS are encoded by the GLU-1 loci and regulated at the transcriptional level by interaction between cis-elements and transcription factors (TFs). We recently validated the function of conserved cis-regulatory modules (CCRMs) in GLU-1 promoters, but their interacting TFs remained uncharacterized. Here we identified a CCRM-binding NAM-ATAF-CUC (NAC) protein, TaNAC100, through yeast one-hybrid (Y1H) library screening. Transactivation assays demonstrated that TaNAC100 could bind to the GLU-1 promoters and repress their transcription activity in tobacco (Nicotiana benthamiana). Overexpression of TaNAC100 in wheat significantly reduced the contents of HMW-GS and other SSPs as well as total seed protein. This was confirmed by transcriptome analyses. Conversely, enhanced expression of TaNAC100 increased seed starch contents and expression of key starch synthesis-related genes, such as TaGBSS1 and TaSUS2. Y1H assays also indicated TaNAC100 binding with the promoters of TaGBSS1 and TaSUS2. These results suggest that TaNAC100 functions as a hub controlling seed protein and starch synthesis. Phenotypic analyses showed that TaNAC100 overexpression repressed plant height, increased heading date, and promoted seed size and thousand kernel weight. We also investigated sequence variations in a panel of cultivars, but did not identify significant association of TaNAC100 haplotypes with agronomic traits. The findings not only uncover a useful gene for wheat breeding but also provide an entry point to reveal the mechanism underlying metabolic balance of seed storage products.

Allelic variation and genetic diversity of HMW glutenin subunits in Chinese wheat (Triticum aestivum L.) landraces and commercial cultivars.

Wheat landraces have abundant genetic variation at the Glu-1 loci, which is desirable germplasms for genetic enhancement of modern wheat varieties, especially for quality improvement. In the current study, we analyzed the allelic variations of the Glu-1 loci of 597 landraces and 926 commercial wheat varieties from the four major wheat-growing regions in China using SDS-PAGE. As results, alleles Null, 7+8, and 2+12 were the dominant HMW-GSs in wheat landraces. Compared to landraces, the commercial varieties contain higher frequencies of high-quality alleles, including 1, 7+9, 14+15 and 5+10. The genetic diversity of the four commercial wheat populations (alleles per locus (A) = 7.33, percent polymorphic loci (P) = 1.00, effective number of alleles per locus (Ae) = 2.347 and expected heterozygosity (He) = 0.563) was significantly higher than that of the landraces population, with the highest genetic diversity found in the Southwestern Winter Wheat Region population. The genetic diversity of HMW-GS is mainly present within the landraces and commercial wheat populations instead of between populations. The landraces were rich in rare subunits or alleles may provide germplasm resources for improving the quality of modern wheat.

Molecular Characterization and SNP-Based Molecular Marker Development of Two Novel High Molecular Weight Glutenin Genes from Triticum spelta L.

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.

Comparison of effect of using hard and soft wheat on the high molecular weight-glutenin subunits profile and the quality of produced cookie.

Twelve wheat genotypes with variable grain hardness were evaluated for grain, flour, pasting, dough rheological properties, high molecular weight glutenin subunits (HMW-GS) and their relationship with cookie quality characteristics. The degree of hardness played an important role in the expression of characters under study. Genotypes with higher grain hardness index (GHI) showed higher dough development time and dough stability. GHI and solvent retention capacity were positively related to each other and negatively to spread factor. GluD1 locus of majority of hard wheat genotypes showed 5 + 10 subunit while soft wheat (SW) genotypes with 2 + 12 subunit related to gluten quality and dough properties. Overall, variation in subunits at GluD1 locus led to greater variation amongst studied genotypes followed by GluB1 and GluA1. Subunits Null at GluA1, 20, 7 + 8 and 7 + 9 at GluB1, and 2 + 12 and 5 + 10 at GluD1 showed a profound effect on flour, dough and cookie quality. Distribution of different HMW-GS, gluten characteristics and GHI, thus emerged as major parameters for selection of wheat genotypes for development of cookies. SW (QBP 13-11) with the lowest GHI and HMW-GS profile (2*, 7 and 2 + 12 subunit) showed the highest cookie SF and the lowest BS, thereby, turning out to be the best suitable genotype for producing cookies. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05272-5.

Post-translational cleavage of HMW-GS Dy10 allele improves the cookie-making quality in common wheat (Triticum aestivum).

Wheat is a major staple food crop worldwide because of the unique properties of wheat flour. High molecular weight glutenin subunits (HMW-GSs), which are among the most critical determinants of wheat flour quality, are responsible for the formation of glutenin polymeric structures via interchain disulfide bonds. We herein describe the identification of a new HMW-GS Dy10 allele (Dy10-m619SN). The amino acid substitution (serine-to-asparagine) encoded in this allele resulted in a partial post-translational cleavage that produced two new peptides. These new peptides disrupted the interactions among gluten proteins because of the associated changes to the number of available cysteine residues for interchain disulfide bonds. Consequently, Dy10-m619SN expression decreased the size of glutenin polymers and weakened glutens, which resulted in wheat dough with improved cookie-making quality, without changes to the glutenin-to-gliadin ratio. In this study, we clarified the post-translational processing of HMW-GSs and revealed a new genetic resource useful for wheat breeding. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01238-9.

A Rapid, Reliable RP-UPLC Method for Large-Scale Analysis of Wheat HMW-GS Alleles.

High-molecular-weight glutenin subunits (HMW-GS) account for only 10% of total wheat storage proteins, but play an important role in the processing quality of wheat flour. Therefore, identifying HMW-GS alleles associated with good end-use quality provides important information for wheat breeders. To rapidly, accurately and reproducibly identify HMW-GS, we established an optimized reversed-phase ultra-performance liquid chromatography (RP-UPLC) method. Separation parameters were optimized using an ACQUITY UPLC Protein BEH C4 column and stepwise ACN gradient, and the separation patterns and retention times (RTs) of 22 subunits were comparatively analyzed in 16 standard wheat cultivars. All HMW-GS proteins were well separated within about 5.5 min, and all analyses were complete within 12 min. We distinguished the 16 subunits based on RT, although three subunits in 1Bx (1Bx7/1Bx7OE and 1Bx17) and three subunits in 1By (1By8*, 1By9 and 1By15) had overlapping RTs; these were differentiated by SDS-PAGE. To distinguish 1Bx7 and 1Bx7OE, which differ in protein abundance, RP-UPLC was combined with PCR analysis of DNA junction markers. The optimized method was successfully applied to determine HMW-GS alleles in a large collection of bread wheat germplasm (1787 lines). This protocol is an appropriate option for selecting lines harboring favorable HMW-GS alleles in wheat breeding.

Analyzing the action of evolutionarily conserved modules on HMW-GS 1Ax1 promoter activity.

KEY MESSAGE: The specific and high-level expression of 1Ax1 is determined by different promoter regions. HMW-GS synthesis occurs in aleurone layer cells. Heterologous proteins can be stored in protein bodies. High-molecular-weight glutenin subunit (HMW-GS) is highly expressed in the endosperm of wheat and relative species, where their expression level and allelic variation affect the bread-making quality and nutrient quality of flour. However, the mechanism regulating HMW-GS expression remains elusive. In this study, we analyzed the distribution of cis-acting elements in the 2659-bp promoter region of the HMW-GS gene 1Ax1, which can be divided into five element-enriched regions. Fragments derived from progressive 5' deletions were used to drive GUS gene expression in transgenic wheat, which was confirmed in aleurone layer cells, inner starchy endosperm cells, starchy endosperm transfer cells, and aleurone transfer cells by histochemical staining. The promoter region ranging from - 297 to - 1 was responsible for tissue-specific expression, while fragments from - 1724 to - 618 and from - 618 to - 297 were responsible for high-level expression. Under the control of the 1Ax1 promoter, heterologous protein could be stored in the form of protein bodies in inner starchy endosperm cells, even without a special location signal. Our findings not only deepen our understanding of glutenin expression regulation, trafficking, and accumulation but also provide a strategy for the utilization of wheat endosperm as a bioreactor for the production of nutrients and metabolic products.

Mass spectrometry of in-gel digests reveals differences in amino acid sequences of high-molecular-weight glutenin subunits in spelt and emmer compared to common wheat.

High-molecular-weight glutenin subunits (HMW-GS) play an important role for the baking quality of wheat. The ancient wheats emmer and spelt differ in their HMW-GS pattern compared to modern common wheat and this might be one reason for their comparatively poor baking quality. The aim of this study was to elucidate similarities and differences in the amino acid sequences of two 1Bx HMW-GS of common wheat, spelt and emmer. First, the sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE) system was optimized to separate common wheat, spelt and emmer Bx6 and Bx7 from other HMW-GS (e.g., 1Ax and 1By) in high concentrations. The in-gel digests of the Bx6 and Bx7 bands were analyzed by untargeted LC-MS/MS experiments revealing different UniProtKB accessions in spelt and emmer compared to common wheat. The HMW-GS Bx6 and Bx7, respectively, of emmer and spelt showed differences in the amino acid sequences compared to those of common wheat. The identities of the peptide variations were confirmed by targeted LC-MS/MS. These peptides can be used to differentiate between Bx6 and Bx7 of spelt and emmer and Bx6 and Bx7 of common wheat. The findings should help to increase the reliability and curation status of wheat protein databases and to understand the effects of protein structure on the functional properties. Graphical abstract.

Molecular Marker Based Design for Breeding Wheat Lines with Multiple Resistance and Superior Quality.

There has not been a major wheat stem rust epidemic worldwide since the 1970s, but the emergence of race TTKSK of Puccinia graminis f. sp. tritici in 1998 presented a great threat to the world wheat production. Single disease-resistance genes are usually effective for only several years before the pathogen changes genetically to overcome the resistance. Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is one of the most common and persistent wheat diseases worldwide. The development of varieties with multiple resistance is the most economical and effective strategy for preventing stripe rust and stem rust, the two main rust diseases constraining wheat production. Plateau 448 has been widely used in the spring wheat growing region in northwest China, but it has become susceptible to stripe rust and is susceptible to TTKSK. To produce more durable resistance to race TTKSK as well as to stripe rust, four stem rust resistance genes (Sr33, Sr36, Sr-Cad, and Sr43) and three stripe rust resistance genes (Yr5, Yr18, and Yr26) were simultaneously introgressed into Plateau 448 to improve its stem rust (Ug99) and stripe rust resistance using a marker-assisted backcrossing strategy combined with phenotypic selection. We obtained 131 BC1F5 lines that pyramided two to four Ug99 resistance genes and one to two Pst resistance genes simultaneously. Thirteen of these lines were selected for their TTKSK resistance, and all of them exhibited near immunity or high resistance to TTKSK. Among the 131 pyramided lines, 95 showed high resistance to mixed Pst races. Nine lines exhibited not only high resistance to TTKSK and Pst but also better agronomic traits and high-molecular-weight glutenin subunit compositions than Plateau 448.

High-Molecular-Weight Glutenin Subunits: Genetics, Structures, and Relation to End Use Qualities.

High-molecular-weight glutenin subunits (HMW-GSs) are storage proteins present in the starchy endosperm cells of wheat grain. Encoding the synthesis of HMW-GS, the Glu-1 loci located on the long arms of group 1 chromosomes of the hexaploid wheat (1A, 1B, and 1D) present multiple allelism. In hexaploid wheat cultivars, almost all of them express 3 to 5 HMW-GSs and the 1Ay gene is always silent. Though HMW-GSs are the minor components in gluten, they are crucial for dough properties, and certain HMW-GSs make more positive contributions than others. The HMW-GS acts as a "chain extender" and provides a disulfide-bonded backbone in gluten network. Hydrogen bonds mediated by glutamine side chains are also crucial for stabilizing the gluten structure. In most cases, HMW-GSs with additional or less cysteines are related to the formation of relatively more or less interchain disulfide bonds and HMW-GSs also affect the gluten secondary structures, which in turn impact the end use qualities of dough.

Variations in yield and gluten proteins in durum wheat varieties under late-season foliar versus soil application of nitrogen fertilizer in a northern Mediterranean environment.

BACKGROUND: With the increasing demand for high-quality foodstuffs and concern for environmental sustainability, late-season nitrogen (N) foliar fertilization of common wheat is now an important and widespread practice. This study investigated the effects of late-season foliar versus soil N fertilization on yield and protein content of four varieties of durum wheat, Aureo, Ariosto, Biensur and Liberdur, in a three-year field trial in northern Italy. RESULTS: Variations in low-molecular-weight glutenins (LMW-GS), high-molecular-weight glutenins (HMW-GS) and gliadins were assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). It was found that N applied to the canopy did not improve protein rate compared with N application to the soil (general mean 138 mg g-1 ), but moderately increased productivity in the high-yielding varieties Liberdur and Biensur (three-year means 7.23 vs 7.13 and 7.53 vs 7.09 t ha-1 respectively). Technological quality was mainly related to variety choice, Aureo and Ariosto having higher protein rates and glutenin/gliadin ratios. Also found was a strong 'variety × N application method' interaction in the proportions of protein subunits within each class, particularly LMW-GS and gliadins. A promising result was the higher N uptake efficiency, although as apparent balance, combined with higher HMW/LMW-GS ratio in var. Biensur. CONCLUSION: Late-season foliar N fertilization allows N fertilizer saving, potentially providing environmental benefits in the rainy climate of the northern Mediterranean area, and also leads to variety-dependent up-regulation of essential LMW-GS and gliadins. Variety choice is a key factor in obtaining high technological quality, although it is currently associated with modest grain yield. This study provides evidence of high quality in the specific high-yielding variety Biensur, suggesting its potential as a mono-varietal semolina for pasta production. © 2017 Society of Chemical Industry.

Genetic diversity, population structure and marker-trait associations for agronomic and grain traits in wild diploid wheat Triticum urartu.

BACKGROUND: Wild diploid wheat, Triticum urartu (T. urartu) is the progenitor of bread wheat, and understanding its genetic diversity and genome function will provide considerable reference for dissecting genomic information of common wheat. RESULTS: In this study, we investigated the morphological and genetic diversity and population structure of 238 T. urartu accessions collected from different geographic regions. This collection had 19.37 alleles per SSR locus and its polymorphic information content (PIC) value was 0.76, and the PIC and Nei's gene diversity (GD) of high-molecular-weight glutenin subunits (HMW-GSs) were 0.86 and 0.88, respectively. UPGMA clustering analysis indicated that the 238 T. urartu accessions could be classified into two subpopulations, of which Cluster I contained accessions from Eastern Mediterranean coast and those from Mesopotamia and Transcaucasia belonged to Cluster II. The wide range of genetic diversity along with the manageable number of accessions makes it one of the best collections for mining valuable genes based on marker-trait association. Significant associations were observed between simple sequence repeats (SSR) or HMW-GSs and six morphological traits: heading date (HD), plant height (PH), spike length (SPL), spikelet number per spike (SPLN), tiller angle (TA) and grain length (GL). CONCLUSIONS: Our data demonstrated that SSRs and HMW-GSs were useful markers for identification of beneficial genes controlling important traits in T. urartu, and subsequently for their conservation and future utilization, which may be useful for genetic improvement of the cultivated hexaploid wheat.

Evaluation of HMW-GS 20 and 2.2 from near isogenic lines of wheat variety HD2329 for bread quality improvement.

BACKGROUND: Hexaploid wheat (Triticum aestivum L.) dominates the list of the most important human food sources ever. Its complex genetic background is the reason behind the wide diversity that exists in nutritional as well as food end-product quality. High-molecular-weight glutenin sub-units (HMW-GS) are the main grain storage proteins in the endosperm of wheat and related species. It is well established that the composition and quantity of allelic variation in HMW-GS genes substantially affect the taste and appearance of dough products and therefore work in this area is highly desired. RESULTS: A significant positive effect on wheat dough quality traits was observed among near isogenic lines of HMW-GS sub-units 20 and 2.2 in wheat variety HD2329 during quality evaluation of data generated over 2 years. A remarkably significant (P < 0.01) effect was observed on dough quality parameters like ratio of wet gluten/dry gluten, SDS sedimentation, farinogram parameters, and bread/chapatti traits whereas flour protein and dry gluten content showed an insignificant effect. CONCLUSION: HMW-GS 20 was found to be superior to HMW-GS 2.2 in terms of dough quality and both the near isogenic lines developed by us were found to be highly superior to the recurrent parent HD2329. As we know that the improvement of flour quality based on superior HMW-GS alleles is necessary to meet changing consumer demand, the study can be of immense use to future researchers who can target these HMW sub-units 20 and 2.2 in breeding programmes for the improvement of wheat end-product quality. © 2017 Society of Chemical Industry.

The influence of Glu-1 and Glu-3 loci on dough rheology and bread-making properties in wheat (Triticum aestivum L.) doubled haploid lines.

BACKGROUND: The major determinants of wheat quality are Glu-1 and Glu-3 glutenin loci and environmental factors. Additive effects of alleles at the Glu-1 and Glu-3 loci, as well as their interactions, were evaluated for dough rheology and baking properties in four groups of wheat doubled haploid lines differing in high- and low-molecular-weight glutenin composition. RESULTS: Flour quality, Reomixer (Reologica Instruments, Lund, Sweden), dough extension, Farinograph (Brabender GmbH, Duisburg, Germany) and baking parameters were determined. Groups of lines with the alleles Glu-A3b and Glu-B3d were characterized by higher values of dough and baking parameters compared to those with the Glu-A3e and Glu-B3a alleles. Effects of interactions between allelic variants at the Glu-1 and Glu-3 loci on Reomixer parameters, dough extension tests and baking parameters were significant, although additive effects of individual alleles were not always significant. CONCLUSION: The allelic variants at Glu-B3 had a much greater effect on dough rheological parameters than the variants at Glu-A3 or Glu-D3 loci. The effect of allelic variations at the Glu-D3 loci on rheological parameters and bread-making quality was non-significant, whereas their interactions with a majority of alleles at the other Glu-1 × Glu-3 loci were significant. © 2017 Society of Chemical Industry.

The trafficking pathway of a wheat storage protein in transgenic rice endosperm.

BACKGROUND AND AIMS: The trafficking of proteins in the endoplasmic reticulum (ER) of plant cells is a topic of considerable interest since this organelle serves as an entry point for proteins destined for other organelles, as well as for the ER itself. In the current work, transgenic rice was used to study the pattern and pathway of deposition of the wheat high molecular weight (HMW) glutenin sub-unit (GS) 1Dx5 within the rice endosperm using specific antibodies to determine whether it is deposited in the same or different protein bodies from the rice storage proteins, and whether it is located in the same or separate phases within these. METHODS: The protein distribution and the expression pattern of HMW sub-unit 1Dx5 in transgenic rice endosperm at different stages of development were determined using light and electron microscopy after labelling with antibodies. KEY RESULTS: The use of HMW-GS-specific antibodies showed that sub-unit 1Dx5 was expressed mainly in the sub-aleurone cells of the endosperm and that it was deposited in both types of protein body present in the rice endosperm: derived from the ER and containing prolamins, and derived from the vacuole and containing glutelins. In addition, new types of protein bodies were also formed within the endosperm cells. CONCLUSIONS: The results suggest that the HMW 1Dx5 protein could be trafficked by either the ER or vacuolar pathway, possibly depending on the stage of development, and that its accumulation in the rice endosperm could compromise the structural integrity of protein bodies and their segregation into two distinct populations in the mature endosperm.

Effects of high-molecular-weight glutenin subunit on hard-steamed bread quality.

Introduction: Steamed bread (SB) is a daily food in many countries in the world, but the relationship between HMW-GS and the quality of SB remain unclear. Methods: This study investigated the effects of 12 subunit combinations on the characteristics of SB, including volume, physical properties, and sensory evaluation, combined with the microstructure and dough rheological properties. Results: The locus effect results showed, volume and physical properties of SB were Glu-D1>Glu-B1>Glu-A1, while sensory scores Glu-B1>Glu-D1>Glu-A1. According to individual subunit effects, subunit 1 at Glu-A1 locus, 7+8 and 7+9 subunits at Glu-B1 locus, and 2+10 and 5+12 subunits at Glu-D1 locus were significantly superior to other subunits in physical indices like volume, chewiness, glueyness, and sensory scores, and were less affected by moisture. The effect of subunits combination is mainly affected by subunits, and the combination of superior subunits tends to make SB quality better. The subunit combinations (1, 7+8, 5+12), (N, 7+9, 2+10) and (1, 7+9, 5+12) had better physical properties indexes, sensory scores, dense, uniform and delicate micro-pore structure, and smaller thickness wall. Discussion: The results showed that protein content, wet gluten content and stability time were the main factors affecting the volume and physical properties of SB. The protein content, wet gluten content and stability time of flour in 7+8, 7+9, 2+10 and 5+12 subunits were higher. Therefore, the quality of SB containing these subunits was found better.

Effect of high-molecular-weight glutenin subunit deletion on gluten functionality and Chinese southern-type steamed bread quality.

High-molecular-weight glutenin subunit (HMW-GS) is key factor in gluten strength and end-use quality. However, the contribution of individual HMW-GS on dough strength and Chinese southern-type steamed bread (CSTSB) quality remained unknown. In this study, we investigated the effects of individual HMW-GS deletion on CSTSB quality. The HMW-GS deletion led to significant reductions in glutenin/gliadin ratios, disulfide bond content, and SDS-unextractable polymeric protein formation. Additionally, HMW-GS deletion resulted in decreased gluten protein chain length, molecular weight, and particle size, contributing to increased thermal instability and reduced crosslinking. The HMW-GS deletion weakened dough strength but improved CSTSB performance, particularly in Dx2d and Dy12d. In-silico analysis further revealed strong interactions between Bx7 and Dx2, primarily driven by desolvation energy, highlighting their crucial role in stabilizing gluten protein interactions.

Wheat quality: A review on chemical composition, nutritional attributes, grain anatomy, types, classification, and function of seed storage proteins in bread making quality.

Wheat (Triticum aestivum L.) belonging to one of the most diverse and substantial families, Poaceae, is the principal cereal crop for the majority of the world's population. This cereal is polyploidy in nature and domestically grown worldwide. Wheat is the source of approximately half of the food calories consumed worldwide and is rich in proteins (gluten), minerals (Cu, Mg, Zn, P, and Fe), vitamins (B-group and E), riboflavin, niacin, thiamine, and dietary fiber. Wheat seed-storage proteins represent an important source of food and energy and play a major role in the determination of bread-making quality. The two groups of wheat grain proteins, i.e., gliadins and glutenins, have been widely studied using SDS-PAGE and other techniques. Sustainable production with little input of chemicals along with high nutritional quality for its precise ultimate uses in the human diet are major focus areas for wheat improvement. An expansion in the hereditary base of wheat varieties must be considered in the wheat breeding program. It may be accomplished in several ways, such as the use of plant genetic resources, comprising wild relatives and landraces, germplasm-assisted breeding through advanced genomic tools, and the application of modern methods, such as genome editing. In this review, we critically focus on phytochemical composition, reproduction growth, types, quality, seed storage protein, and recent challenges in wheat breeding and discuss possible ways forward to combat those issues.

Addition of Psathyrostachys huashanica HMW glutenin subunit expresses positive contribution to protein polymerization and gluten microstructure of receptor wheat.

Psathyrostachys huashanica Keng (2n = 2x = 14, NsNs) is considered as a valuable wild germplasm for wheat improvement on account of its numerous outstanding traits. During this study, 7182-1Ns with higher quality was screened out, a series of experiments were conducted to clarify the reasons of quality improvement. The results indicated 7182-1Ns was carried a novel high-molecular-weight glutenin subunit (HMW-GS) from P. huashanica, designated as P. huashanica' subunit in wheat (HS), which changed the HMW-GS compositions, increased the proportion of glutenins in wheat gluten protein, accelerated the accumulation speed of unextractable polymeric protein (UPP) during grain development stage accelerated, and a denser microstructure of the gluten network was formed in the dough. Therefore, the current research provides important reference on effectively utilize 7182-1Ns as an intermediate germplasm for quality breeding improvement.

Characterization of HMW-GS and evaluation of their diversity in morphologically elite synthetic hexaploid wheats.

High molecular weight glutenin subunit composition and variation in 95 Elite-1 synthetic hexaploid (SH) wheats (Triticum turgidum/Aegilops tauschii; 2n = 6× = 42; AABBDD) were determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis method (SDS-PAGE). Twenty two different alleles at Glu-1 loci in SHs were observed. Forty four different patterns of HMW-GS in synthetics were found. This higher HMW glutenin composition was due to higher proportion of D-genome encoded subunits in these SHs. 8% urea/SDS-PAGE better discriminated subunit 2* than 12% gels. However 12% urea/SDS-PAGE allowed differentiated mobility of Glu-D(t)1 subunits. Genetic variability at Glu-D(t)1 locus was greater than Glu-A1 and Glu-B1 loci. The relative high frequency of superior alleles, Glu-B1b and Glu-D(t)1d indicated the superior bread making quality attributes embedded in these synthetic hexaploid wheats. Of the 95 Elite-1 SHs 27.1% possessed superior alleles at Glu-A1 and 51% had superior alleles at Glu-B1 locus. At Glu-D(t)1 frequency of inferior allele 1Dx2 + 1Dy12 was very low (5.26%) and nine different rare alleles along with the higher frequency (22.1%) of D-genome encoded subunit, 1Dx5 + 1Dy10, were observed. These superior alleles shall form the priority selective sieve for their usage in wheat improvement efforts.