Storage Protein Composition Research Articles

Unlocking the genetic potential of Ethiopian durum wheat landraces with high protein quality: Sources to be used in future breeding for pasta production

AbstractThe content and composition of the grain storage proteins in wheat determine to a high extent its end‐use quality for pasta and bread production. This study aimed to evaluate the content and composition of the grain storage proteins in Ethiopian landraces and cultivars to contribute to future breeding toward improved pasta quality. Thus, 116 landraces and 34 cultivars originating from Ethiopia were grown in three locations, and the protein parameters were analyzed using size exclusion‐high performance liquid chromatography (SE‐HPLC). A considerable variation in the amount of the analyzed protein parameters was found. The genotypes, environments, and interactions contributed significantly (p < 0.001) to the differences obtained. The broad‐sense heritability was high (0.75–0.98) for all protein parameters except for unextractable small monomeric protein (uSMP). Using the principal component analysis (PCA) to evaluate the impact of protein parameters and using either PCA or unweighted pair group method with arithmetic mean (UPGMA) to assess the impact of the genetic composition, the cultivar group was found to form a separate cluster. This indicates that durum wheat improvement in Ethiopia has relied on exotic materials, which might result from a narrow genetic base. Unlike most landraces, most released cultivars showed a high and stable gluten strength across environments. Two landraces, G057 and G107, were found genetically distinct from the released cultivars but with high and stable gluten. The two selected landraces might be of extremely high value for future use in durum wheat breeding programs, as they might be adapted to wide‐ranging Ethiopian growing conditions, they might carry genes of relevance to withstand abiotic and biotic stresses, and they seem to hold essential protein properties, which might result in high‐quality grains for industrial processes.

Climate-Nutrient-Crop Model: Novel Insights into Grain-Based Food Quality.

Mineral nutrients spatiotemporally participate in the biosynthesis and accumulation of storage biopolymers, which directly determines the harvested grain yield and quality. Optimizing fertilizer nutrient availability improves the grain yield, but quality aspects are often underestimated. We hypothesize that extensive mineral nutrients have significant effects on the biosynthesis, content, and composition of storage proteins, ultimately determining physicochemical properties and food quality, particularly in the context of climate change. To investigate this, we hierarchized 16 plant mineral nutrients and developed a novel climate-nutrient-crop model to address the fundamental question of the roles of protein and starch in grain-based food quality. Finally, we recommend increasing the added value of mineral nutrients as a socioeconomic strategy to enhance agro-food profitability, promote environmental sustainability, and improve climate resilience.

Transcriptome Analysis of Developing Grains from Wheat Cultivars TAM 111 and TAM 112 Reveal Cultivar-Specific Regulatory Networks.

Wheat flour’s end-use quality is tightly linked to the quantity and composition of storage proteins in the endosperm. TAM 111 and TAM 112 are two popular cultivars grown in the Southern US Great Plains with significantly different protein content. To investigate regulatory differences, transcriptome data were analyzed from developing grains at early- and mid-filling stages. At the mid-filling stage, TAM 111 preferentially upregulated starch metabolism-related pathways compared to TAM 112, whereas amino acid metabolism and transporter-related pathways were over-represented in TAM 112. Elemental analyses also indicated a higher N percentage in TAM 112 at the mid-filling stage. To explore the regulatory variation, weighted correlation gene network was constructed from publicly available RNAseq datasets to identify the modules differentially regulated in TAM 111 and TAM 112. Further, the potential transcription factors (TFs) regulating those modules were identified using graphical least absolute shrinkage and selection operator (GLASSO). Homologs of the OsNF-Y family members with known starch metabolism-related functions showed higher connectivities in TAM 111. Multiple TFs with high connectivity in TAM 112 had predicted functions associated with ABA response in grain. These results will provide novel targets for breeders to explore and further our understanding in mechanisms regulating grain development.

Sulfur uptake and distribution, grain yield, and quality of hybrid and inbred winter wheat (Triticum aestivum L.) varieties under early and late waterlogging

AbstractBackgroundWaterlogging at early and later growth stages could affect sulfur (S) uptake, distribution, yield, and quality of winter wheat. We hypothesized that the hybrid winter wheat variety (Hyvento), with a high degree of heterosis and genetic diversity, is likely to uptake and utilize S more efficiently and withstands waterlogging better than the inbred wheat variety (Kredo).AimsThe objective of the present study was to investigate the effect of 2‐week waterlogging at the end of tillering stage (Feekes Stage 6) and/or ear emergence stage (Feekes Stage 10.1) on grain yield, yield components, S‐uptake and its partitioning, and composition of grain storage proteins (glutenins and gliadins) of hybrid (Hyvento) and inbred (Kredo) winter wheat varieties.MethodsPlants were grown in large containers (120 L) in a semi‐controlled greenhouse and harvested three times immediately after each waterlogging treatment and at agronomic maturity. Grain yield, S concentration in different plant organs, total protein content, and patterns of gluten proteins (gliadin and glutenin) and their subunits (by sodium dodecyl sulfate–polyacrylamide gel electrophoresis) in grains were evaluated.ResultsGrain yield of the inbred variety was more negatively affected under early and late waterlogging than the hybrid variety and was associated with reduced grain size. The decline in grain yield was significantly higher under late waterlogging (30%–31%) than early waterlogging (17%–18%). Compared to the hybrid variety Hyvento, the waterlogging‐induced decline in S concentration in grains, husk, and straw was markedly lower in the inbred variety Kredo. While early waterlogging did not affect total grain protein content in either of the varieties, late waterlogging significantly reduced the total grain protein content (18%) in the inbred variety Kredo. Similarly, the grain gliadin content of the hybrid variety was not affected by both waterlogged conditions, whereas 32% and 23% reductions were recorded for the inbred variety under early and late waterlogging, respectively. Nevertheless, waterlogging significantly increased the proportion of S‐poor high‐molecular‐weight glutenin subunits and ω‐gliadin in the inbred variety.ConclusionIt could be inferred from the present study that hybrid winter wheat variety is relatively resistant to waterlogging than the inbred wheat variety, and thereby produces higher grain yield. Efficient uptake and metabolism of S could be one of the mechanisms conferring waterlogging resistance in winter wheat.

Combination of two multiplex genome-edited soybean varieties enables customization of protein functional properties

Combination of two multiplex genome-edited soybean varieties enables customization of protein functional properties

Genetic variation for seed storage protein composition in rapeseed (Brassica napus) and development of near‐infrared reflectance spectroscopy calibration equations

AbstractRapeseed protein consists mainly of the seed storage protein cruciferin and napin. Cruciferin and napin have different nutritional values and techno‐functional properties. Shifting the cruciferin/napin ratio towards either more napin or more cruciferin could allow diversified applications. The objective of this study was to investigate the genetic variation of cruciferin and napin in modern winter rapeseed cultivars. Cruciferin and napin contents were analysed by SDS‐PAGE. Genetic variation for both protein fractions was highly significant. Heritabilities were high ranging from 74% for cruciferin to 82% for napin. Napin was positively correlated with glucosinolate (rS = .52**) and seed protein content (rS = .48**). Additional plant material with much larger trait variation was included to develop near‐infrared reflectance spectroscopical calibrations. The Near‐infrared reflectance spectroscopy (NIRS) equations showed high fractions of explained variance in cross and independent validation of around .9 for all traits, indicating that the NIRS equations can be applied in routine screening of plant material.

Wheat Quality Formation and Its Regulatory Mechanism

Elucidation of the composition, functional characteristics, and formation mechanism of wheat quality is critical for the sustainable development of wheat industry. It is well documented that wheat processing quality is largely determined by its seed storage proteins including glutenins and gliadins, which confer wheat dough with unique rheological properties, making it possible to produce a series of foods for human consumption. The proportion of different gluten components has become an important target for wheat quality improvement. In many cases, the processing quality of wheat is closely associated with the nutritional value and healthy effect of the end-products. The components of wheat seed storage proteins can greatly influence wheat quality and some can even cause intestinal inflammatory diseases or allergy in humans. Genetic and environmental factors have great impacts on seed storage protein synthesis and accumulation, and fertilization and irrigation strategies also greatly affect the seed storage protein content and composition, which together determine the final end-use quality of wheat. This review summarizes the recent progress in research on the composition, function, biosynthesis, and regulatory mechanism of wheat storage proteins and their impacts on wheat end-product quality.

Modification of storage proteins in the barley grain increases endosperm zinc and iron under both normal and elevated atmospheric CO2.

Increasing atmospheric CO2 concentration is expected to enhance the grain yield of C3 cereal plants, while at the same time reducing the concentrations of minerals and proteins. This will lead to a lower nutritional quality and increase global problems associated with micronutrient malnutrition. Among the barley grain storage proteins, the C‐hordein fraction has the lowest abundance of sulfur (S) containing amino acids and is poorest in binding of zinc (Zn). In the present study, C‐hordein‐suppressed barley lines with reduced C‐hordein content, obtained by use of antisense or RNAi technology, were investigated under ambient and elevated atmospheric CO2 concentration. Grains of the C‐hordein‐suppressed lines showed 50% increase in the concentrations of Zn and iron (Fe) in the core endosperm relative to the wild‐type under both ambient and elevated atmospheric CO2. Element distribution images obtained using laser ablation‐inductively coupled plasma‐mass spectrometry confirmed the enrichment of Fe and Zn in the core endosperm of the lines with modified storage protein composition. We conclude that modification of grain storage proteins may improve the nutritional value of cereal grain with respect to Zn and Fe under both normal and future conditions of elevated atmospheric CO2.

Storage protein composition during germination and its association with physiological seed quality in common bean

Seed reserve mobilization is considered a post-germination process; however, seed storage protein mobilization occurs during germination. Thus, the knowledge of seed protein composition is important to understand various processes during germination, and it be associated with seed vigor. Therefore, this study aimed to characterize landrace genotypes of common bean (Phaseolus vulgaris) through fractionation of seed storage proteins during germination and to verify the association between seed protein composition and seed vigor. Genotypes of the highest (55 and 81) and lowest (23 and 50) physiological quality were selected. Protein content analysis, profiling, and characterization were performed by combining different hydration times. Mass spectrometry involving in-gel digestion and MALDI-ToF analysis was employed for the qualitative identification of proteins. Glutelin extraction detected the enzyme lipoxygenase in genotypes 55 and 81 alone. In plants, this enzyme may be involved in diverse physiological processes, including growth and development, pest resistance, senescence, and response to wounding. In the process of germination, lipoxygenase removes reactive oxygen species during reserve mobilization; therefore, lipoxygenase may be a candidate biochemical marker for high-vigor genotypes.

Хозяйственно-биологическая характеристика биотипного состава сортов яровой пшеницы

The aim of this work is to study the component composition and intravarietal polymorphism of storage proteins of three soft and one hard varieties of spring wheat and their relationship with a complex of economically valuable traits. The studies were carried out in 2018–2020 by the department of genetics and immunity at the institute, in the conditions of the southeast of the Central Black Earth Region. In the course of the work, the identification of gliadin biotypes was carried out by electrophoresis in 6.5% polyacrylamide gel, the results of which revealed that the genome of the studied varieties contains: Chernozemnouralskaya 2 (5 biotypes), Voronezh 18 (5 biotypes), Voronezh 20 (4 biotypes) and a solid variety Voronezhskaya 13 (1 biotype). The selected biotypes were propagated for 3 years, analyzed and evaluated according to the indicators of the structural analysis of the elements of productivity and quality. Based on this, their economic and biological characteristics were given. It was found that biotypes 3 and 4 of the Chernozemnouralskaya variety 2, biotypes 1 and 2 of the Voronezhskaya 18 variety, biotypes 1 and 2 of the Voronezhskaya 20 variety proved to be the most productive relative to the standard during the study period. As for the quality indicators, as a result of the research the difference in quality of gliadin biotypes was revealed, which is important to take into account in breeding work to increase genetic diversity when creating high-quality varieties. The ones with the best quality were: biotype 1 of the Chernozemnouralskaya variety 2, biotypes 2 and 3 of the Voronezhskaya 18 variety. The best biotypes, distinguished by a complex of economically valuable traits, which differ from the initial variety, can be used in further breeding work for the accelerated creation of highly productive and high-quality spring wheat varieties.

Influence of Drought and Salt Stress on Durum Wheat Grain Quality and Composition: A Review.

Durum wheat is a staple crop for the Mediterranean diet because of its adaptability to environmental pressure and for its large use in cereal-based food products, such as pasta and bread, as a source of calories and proteins. Durum wheat whole grains are also highly valued for their peculiar amount of dietary fiber and minerals, as well as bioactive compounds of particular interest for their putative health-beneficial properties, including polyphenols, carotenoids, tocopherols, tocotrienols, and phytosterols. In Mediterranean environments, durum wheat is mostly grown under rainfed conditions, where the crop often experiences environmental stresses, especially water deficit and soil salinity that may induce a hyperosmotic stress. In particular, changes in C and N accumulation due to these abiotic conditions, during grain filling, can influence starch and storage protein amount and composition in durum wheat caryopsis, thus influencing yield and quality traits. Recent advancements regarding the influence of water deficit and salinity stress on durum wheat are critically discussed. In particular, a focus on stress-induced changes in (a) grain protein content and composition in relation to technological and health quality; (b) starch and dietary fiber accumulation and composition; (c) phytochemical composition; (d) health-related grain micronutrient accumulation, such as Fe and Zn.

Starch molecular fine structure is associated with protein composition in chickpea seed

Chickpea (Cicer arietinum L.) seed is a nutritional food high in starch and protein. This study aims to find the relationships between the molecular fine structure of starch and the composition of storage proteins and metabolic enzymes, using different chickpea varieties. It is found that storage proteins and starch biosynthetic enzymes influence each other. The initial formation of amylopectin molecules is affected by storage proteins, as suggested by the positive correlation (p < 0.01) between the average molecular size of amylopectin and total protein content. In addition, a higher amount of seed globulin could be an indication of higher amylose content and more short – medium amylose chains (degree of polymerization, DP, 118–2000). This study might assist selection of chickpea varieties with desirable qualities, such as low starch digestibility.

Effects of water deficit and high N fertilization on wheat storage protein synthesis, gluten secondary structure, and breadmaking quality

The content and composition of wheat storage proteins are the major determinants of dough rheological properties and breadmaking quality and are influenced by cultivation conditions. This study aimed to investigate the effects of water deficit and high N-fertilizer application on wheat storage protein synthesis, gluten secondary structure, and breadmaking quality. Reverse-phase ultrahigh-performance liquid chromatography analysis showed that storage protein and gluten macropolymer accumulation was promoted under both independent applications and a combination of water-deficit and high N-fertilizer treatments. Fourier-transform infrared spectroscopy showed that water deficit and high N-fertilizer treatments generally improved protein secondary structure formation and lipid accumulation, and reduced flour moisture. In particular, high N-fertilizer application increased β-sheet content by 10.4% and the combination of water-deficit and high N-fertilizer treatments increased random coil content by 7.6%. These changes in gluten content and secondary structure led to improved dough rheological properties and breadmaking quality, including superior loaf internal structure, volume, and score. Our results demonstrate that moderately high N-fertilizer application under drought conditions can improve gluten accumulation, gluten secondary structure formation, and baking quality.

Influence of starch fine structure and storage proteins on the eating quality of rice varieties with similar amylose contents.

Rice eating quality largely dictates consumer preference, and the demand for new rice varieties with excellent eating quality from farmers is increasing. Identification of factors contributing to eating quality is helpful for developing high-quality rice varieties. Two groups of rice with different apparent amylose content (AACs) were used in this study. One group contained four varieties with low AACs (8.8-9.4%), whereas the other contained four traditional varieties with medium AACs (17.2-17.5%). The physicochemical properties, starch fine structure and crystallinity and storage protein composition of the two groups were analyzed. We found that, in both groups, the rice varieties with high eating quality had more short-chain amylopectin, lower glutelin and prolamin content, and a higher albumin content. In addition, the low-AAC varieties produced opaque endosperms, which may result from an increased number of pores in the center of starch granules. Both the fine structure of starch and the storage protein composition were closely related to rice eating quality. In both groups, short branch-chain amylopectin, short-chain amylopectin [degree of polymerization (DP) 6-12], and albumin had positive effects on eating quality. By contrast, long branch-chain amylopectin, long-chain amylopectin (DP 35-60), glutelin and prolamin had adverse effects on eating quality of rice. © 2020 Society of Chemical Industry.

Changes in storage protein composition on genetic removal of Kunitz trypsin inhibitor maintain protein content in soybean (Glycine max)

Abstract Genetic removal of Kunitz trypsin inhibitor (KTI), a proteinaceous anti-nutritional factor, in soybean is anticipated to cause loss in protein content. In the present study, marker-assisted survey of 180 recombinant inbred lines (RILs) developed from the cross KTI ​+ ​ve (‘SL525’) ​× ​KTI-free parent (‘NRC101’) in tandem with quantification of protein content led to the identification of KTI-free RILs with normal-protein content. SDS-PAGE analysis of KTI-free parent, KTI ​+ ​ve parent, low-protein KTI-free, and 2 normal-protein KTI-free RILs showed random increase and decrease in the concentration of different subunits of glycinin (11S), β-conglycinin (7S) and other storage protein in the normal-protein KTI-free RILs compared to KTI ​+ ​ve parent. KTI-free RILs with normal-protein content showed higher concentration of acidic and basic subunits of 11S and β-subunit of 7S fraction compared to the low-protein KTI-free RIL and KTI-free parent. The study suggested that it is possible to breed KTI-free soybean without reducing the protein content.

Loss of Function of an RNA Polymerase III Subunit Leads to Impaired Maize Kernel Development.

Kernel size is an important factor determining grain yield. Although a number of genes affecting kernel development in maize (Zea mays) have been identified by analyzing kernel mutants, most of the corresponding mutants cannot be used in maize breeding programs due to low germination or incomplete seed development. Here, we characterized small kernel7, a recessive small-kernel mutant with a mutation in the gene encoding the second-largest subunit of RNA polymerase III (RNAPΙΙΙ; NRPC2). A frame shift in ZmNRPC2 leads to a premature stop codon, resulting in significantly reduced levels of transfer RNAs and 5S ribosomal RNA, which are transcribed by RNAPΙΙΙ. Loss-of-function nrpc2 mutants created by CRISPR/CAS9 showed significantly reduced kernel size due to altered endosperm cell size and number. ZmNRPC2 affects RNAPIII activity and the expression of genes involved in cell proliferation and endoreduplication to control kernel development via physically interacting with RNAPIII subunits RPC53 and AC40, transcription factor class C1 and Floury3. Notably, unlike the semidominant negative mutant floury3, which has defects in starchy endosperm, small kernel7 only affects kernel size but not the composition of kernel storage proteins. Our findings provide novel insights into the molecular network underlying maize kernel size, which could facilitate the genetic improvement of maize in the future.

Effects of a late N fertiliser dose on storage protein composition and bread volume of two wheat varieties differing in quality

Wheat is an important source of energy and protein for humans all over the world and is mainly consumed in form of baked goods, for which a high baking quality is required. The main parameter for bread-making quality predictions of wheat flours is the grain protein concentration (GPC). Therefore, the GPC determines the value of the harvested wheat. Unfortunately, the GPC appears to be no longer an appropriate parameter for baking quality evaluation, given that, especially for high protein varieties, the correlation between GPC and bread volume is poor. A late N application is commonly used to increase GPC and enhance the bread-making quality of wheat flours. To minimise the environmental problems involved in the late use of N fertilisers, it is important to know how much N is necessary to achieve the desired effects. Therefore, in this study, the effects of two different doses of late N application on the GPC, as well as storage protein composition and bread volume were tested in two wheat varieties from different quality groups under field conditions in Germany. The findings of this experiment demonstrate that a low late N application appears to be sufficient to achieve a good baking quality of wheat flours. These results confirm the presumption that GPC is not a suitable parameter for bread-making quality predictions. As the relationships between the single storage protein fractions and bread volume were poor, it can be concluded that only the combined alterations within all gluten protein fractions explain the rise in bread volume.

Agrobiological characteristics of spelt wheat and intermediate wheatgrass under the conditions of the Right-Bank Forest-Steppe of Ukraine

Agrobiological characteristics of spelt wheat and intermediate wheatgrass under the conditions of the Right-Bank Forest-Steppe of Ukraine

The overexpression of high-molecular-weight glutenin subunit Bx7 improves the dough rheological properties by altering secondary and micro-structures of wheat gluten.

Bread wheat (Triticum aestivum L.) is one of the crucial cereals consumed by human beings and wheat gluten, the natural macromolecules, mainly determines the processing quality of wheat dough. The high-molecular-weight glutenin subunits (HMW-GSs) of gluten proteins are recognized as one of the main components regulating the rheological properties of dough. The overexpressed Bx7 subunit (Bx7OE) has been reported to improve wheat quality and rheological properties of dough, however its effect on secondary and micro- structures of gluten is still unclear. In this study, we evaluated the composition of main storage proteins in wheat grains of two near-isogenic lines and studied the effect of Bx7 subunit expression level on the secondary structures of gluten and micro-structure of gluten during dough mixing process. Results showed the protein content, HMW-GSs proportion in total glutenins and free sulfhydryl content increased in the flour of HMW-Bx7OE wheat line, and the accumulation of unextractable polymeric protein during grain filling stage accelerated. It was found that the content of β-sheets in secondary structures of gluten increased and a more compact micro-structure of gluten network formed in the dough. Protein network analysis characterized and quantified the alterations in the gluten micro-structure. In the process of dough mixing, protein area, total protein length, number of junctions and branching rate reach the peak at dough development time, which was consistent with Chopin mixing profile. Interestingly, during dough mixing, the above-mentioned parameters of HMW-Bx7OE showed less changes than those of HMW-Bx7 wheat line, indicating Bx7OE improved the dough stability during mixing. To conclude, Bx7OE alters the secondary and micro- structures of gluten and thus improves the mixing and rheological properties of wheat dough.

Effects of water deficit and different nitrogen fertilizer treatments on the quality of wheat for Chinese fresh white noodles and steamed bread and the composition of storage proteins.

Noodles and steamed bread are popular wheat products consumed worldwide, particularly in China and other Asian countries. We performed the first comprehensive study of the influence of water deficits and different nitrogen fertilizer applications on two elite Chinese bread wheat cultivars, Zhongmai 175 and Jimai 22, which are distinct in gluten strength. These wheat cultivars were tested to determine the qualities that are optimal for the production of Chinese fresh white noodles (CFWN) and northern-style Chinese steamed bread (NCSB), and storage protein composition. Water deficit and high nitrogen (N) fertilizer application promoted total grain protein content and the accumulation of gliadins and glutenins, while low N resulted in the opposite results. Water deficit and high N fertilizer in Jimai 22, with medium-to-strong gluten strength significantly improved NCSB and CFWN qualities. The quality of CFWN under low N, and that of NCSB under both high and low N conditions, was significantly reduced. However, NCSB and CFWN quality in Zhongmai 175 with weak-to-medium gluten strength was not significantly affected by water deficit and different N fertilizer applications. Grain subproteome analysis revealed that considerable cultivar-specific gliadins and glutenins showed significant accumulation changes in response to water deficit and high / low N fertilizer treatment, which could be responsible for NCSB and CFWN quality changes under different treatments. Water deficit and high / low N fertilizer treatments caused changes in cultivar-specific storage protein composition, resulting in differences in the accumulation of gliadins, glutenins, and the quality of NCSB and CFWN. © 2019 Society of Chemical Industry.