Seed Storage Protein Content Research Articles

Analysis of nucleotide sequences and expression levels of the ABI3 and FUS3 genes in Pisum sativum L. genotypes differs in seed storage protein content

Analysis of nucleotide sequences and expression levels of the ABI3 and FUS3 genes in Pisum sativum L. genotypes differs in seed storage protein content

Nuclear factor-Y-polycomb repressive complex2 dynamically orchestrates starch and seed storage protein biosynthesis in wheat.

The endosperm in cereal grains is instrumental in determining grain yield and seed quality, as it controls starch and seed storage protein (SSP) production. In this study, we identified a specific nuclear factor-Y (NF-Y) trimeric complex in wheat (Triticum aestivum L.), consisting of TaNF-YA3-D, TaNF-YB7-B, and TaNF-YC6-B, and exhibiting robust expression within the endosperm during grain filling. Knockdown of either TaNF-YA3 or TaNF-YC6 led to reduced starch but increased gluten protein levels. TaNF-Y indirectly boosted starch biosynthesis genes by repressing TaNAC019, a repressor of cytosolic small ADP-glucose pyrophosphorylase 1a (TacAGPS1a), sucrose synthase 2 (TaSuS2), and other genes involved in starch biosynthesis. Conversely, TaNF-Y directly inhibited the expression of Gliadin-γ-700 (TaGli-γ-700) and low molecular weight-400 (TaLMW-400). Furthermore, TaNF-Y components interacted with SWINGER (TaSWN), the histone methyltransferase subunit of Polycomb repressive complex 2 (PRC2), to repress TaNAC019, TaGli-γ-700, and TaLMW-400 expression through trimethylation of histone H3 at lysine 27 (H3K27me3) modifications. Notably, weak mutation of FERTILIZATION INDEPENDENT ENDOSPERM (TaFIE), a core PRC2 subunit, reduced starch but elevated gliadin and LMW-GS contents. Intriguingly, sequence variation within the TaNF-YB7-B coding region was linked to differences in starch and SSP content. Distinct TaNF-YB7-B haplotypes affect its interaction with TaSWN-B, influencing the repression of targets like TaNAC019 and TaGli-γ-700. Our findings illuminate the intricate molecular mechanisms governing TaNF-Y-PRC2-mediated epigenetic regulation for wheat endosperm development. Manipulating the TaNF-Y complex holds potential for optimizing grain yield and enhancing grain quality.

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.

Seed storage protein changes and mobilization pattern in Bambaranut (Vigna subterranea) (L.) Verdc. during germination

The germination of seeds involves series of events during which mobilization and utilization of seed storage proteins occur. This study is aimed at determining the changes in total and fractions of seed storage protein in six bambaranut landraces during 96 hrs germination period. The study assessed the changes in seed storage protein content, storage protein profile, endopeptidase activity, free amino acids and gibberellic acid levels. Significant (p<0.05) decrease in total storage protein after 24 hrs, albumin from 48 hrs and globulin and glutelin after 72 hrs germination period were observed in the studied landraces. Prolamin showed significant (p<0.05) decrease after 48 hrs in all the landraces. Five peptide bands were detected in the six landraces with molecular weights corresponding to 97.4 kDa, 45 kDa, 29 kDa, 20.1 kDa and 18 kDa. Peptide bands with molecular weight of 97 kDa and 29 kDa decreased in intensity after 48 hrs of germination in four landraces. Free amino acids content significantly (p<0.05) increased following 24 hrs germination period in all the landraces. The activity of endopeptidase increased significantly (p<0.05), reaching maximum after 96 hrs germination. Significant (p<0.05) increase in gibberellic acid level throughout germination period was also observed. Although slow degradation rate of storage proteins was observed, there was variation in the rate at which storage protein and its fractions decreased among the bambaranut landraces during germination. This variation could be utilized towards obtaining improved bambaranut genotypes with better germination characteristics.

Modeling spatial trends and enhancing genetic selection: An approach to soybean seed composition breeding

AbstractSpatial variation is a recurrent issue in field trials and can cause obstacles in terms of genetic selection. Analyses that account for spatial variation within location can lead breeders to predict genetic values accurately across locations in multi‐environment trials (METs). The present study aims to fit spatial models for analyzing soybean [Glycine max (L.) Merr.] seed composition traits using a two‐stage analysis pipeline and to assess its efficiency relative to a single‐stage analysis setting. Seed protein content (SPC), seed oil content (SOC), and seed storage protein content (SSP) data were collected from 283 soybean genotypes tested in four environments (C1, C2, V1, and V2). In Stage 1 of the two‐stage analysis, a randomized complete block (RCB) design model as well as four two‐dimensional first‐order (AR1 ⊗ AR1) spatial models were fit in each dataset to determine the most suitable model for genetic prediction. Predicted genetic values were used as input data for Stage 2. The most used spatial model [5] in Stage 1 of this study had accommodated local and global residuals. The autocorrelation estimates depicted spatial trends, especially in terms of rows, while column autocorrelation coefficients were low for C1 and C2 because of the limited number of blocks and their short length. Broad‐sense heritability, mean accuracy, and selection gains were greater for all traits in the two‐stage analysis than in the single‐stage analysis. The two‐stage analysis leveraged the spatial model fitting in the Stage 1 and proved to be advantageous for soybean seed composition breeding.

A novel NAC family transcription factor SPR suppresses seed storage protein synthesis in wheat

SummaryThe synthesis of seed storage protein (SSP) is mainly regulated at the transcriptional level. However, few transcriptional regulators of SSP synthesis have been characterized in common wheat (Triticum aestivum) owing to the complex genome. As the A genome donor of common wheat, Triticum urartu could be an elite model in wheat research considering its simple genome. Here, a novel NAC family transcription factor TuSPR from T. urartu was found preferentially expressed in developing endosperm during grain‐filling stages. In common wheat transgenically overexpressing TuSPR, the content of total SSPs was reduced by c. 15.97% attributed to the transcription declines of SSP genes. Both in vitro and in vivo assays showed that TuSPR bound to the cis‐element 5′‐CANNTG‐3′ distributed in SSP gene promoters and suppressed the transcription. The homolog in common wheat TaSPR shared a conserved function with TuSPR on SSP synthesis suppression. The knock‐down of TaSPR in common wheat resulted in 7.07%–20.34% increases in the total SSPs. Both TuSPR and TaSPR could be superior targets in genetic engineering to manipulate SSP content in wheat, and this work undoubtedly expands our knowledge of SSP gene regulation.

OsNAC-like transcription factor involved in regulating seed-storage protein content at different stages of grain filling in rice under aerobic conditions

In this study, we show that NAC-like transcription factor (TF) has 90% sequence similarity with cDNA of the OsNac5 gene present in the NCBI database. Phylogenetic analysis of the NAC gene family was performed with inclusion of the highly diverse C-terminal sequences. We report that this gene is also found to be orthologous to Glycine max NAC8, NAC2, Triticum aestivum NAC6 and paralogous to OsNAC6. mRNA was purified from five recombinant inbred lines (RILs) and parents of rice at three different stages of grain filling under aerobic conditions, with grain protein content (GPC) spanning from 4 to 14%. The NAC-like TF encoding a protein was found to be upregulated at the S2 stage in the leaf (3.9-fold) and panicle (1.84-fold) of parent HPR14 and in five RILs (1.9 to 4.51-fold in leaves and 0.47 to 3.2-fold in panicles). Expression analysis of the NAC-like TF encoding a protein for the rice gene was found to be upregulated at the S2 stage in the leaf and panicle of parental line HPR14 and RILs with high protein content.

Genetic Basis of Variation in Rice Seed Storage Protein (Albumin, Globulin, Prolamin, and Glutelin) Content Revealed by Genome-Wide Association Analysis.

Rice seed storage protein (SSP) is an important source of nutrition and energy. Understanding the genetic basis of SSP content and mining favorable alleles that control it will be helpful for breeding new improved cultivars. An association analysis for SSP content was performed to identify underlying genes using 527 diverse Oryza sativa accessions grown in two environments. We identified more than 107 associations for five different traits, including the contents of albumin (Alb), globulin (Glo), prolamin (Pro), glutelin (Glu), and total SSP (Total). A total of 28 associations were located at previously reported QTLs or intervals. A lead SNP sf0709447538, associated for Glu content in the indica subpopulation in 2015, was further validated in near isogenic lines NIL(Zhenshan97) and NIL(Delong208), and the Glu phenotype had significantly difference between two NILs. The association region could be target for map-based cloning of the candidate genes. There were 13 associations in regions close to grain-quality-related genes; five lead single nucleotide polymorphisms (SNPs) were located less than 20 kb upstream from grain-quality-related genes (PG5a, Wx, AGPS2a, RP6, and, RM1). Several starch-metabolism-related genes (AGPS2a, OsACS6, PUL, GBSSII, and ISA2) were also associated with SSP content. We identified favorable alleles of functional candidate genes, such as RP6, RM1, Wx, and other four candidate genes by haplotype analysis and expression pattern. Genotypes of RP6 and RM1 with higher Pro were not identified in japonica and exhibited much higher expression levels in indica group. The lead SNP sf0601764762, repeatedly detected for Alb content in 2 years in the whole association population, was located in the Wx locus that controls the synthesis of amylose. And Alb content was significantly and negatively correlated with amylose content and the level of 2.3 kb Wx pre-mRNA examined in this study. The associations or candidate genes identified would provide new insights into the genetic basis of SSP content that will help in developing rice cultivars with improved grain nutritional quality through marker-assisted breeding.

Drought Stress Tolerance of Faba Bean as Studied by Morphological Traits and Seed Storage Protein Pattern

Eight economical Egyptian faba bean (Vicia faba L.) varieties had been evaluated under different drought stress levels and their seed storage protein content patterns under drought stress conditions had been studied and compared with pattern under normal conditions. Analysis of variance of the morphological trait revealed highly significant differences among both treatments and genotypes for the most of studied traits The susceptibility test for drought tolerance revealed that the variety ‘Giza 3’ showed the highest statistical significant susceptibility to drought stress and could be considered as susceptible variety for drought stress, while the variety ‘Giza 843’ was more tolerant to drought stress. Although ‘Giza 3’ variety gave the highest mean across all genotypes for the most of the morphological traits, it was the most drought susceptible variety. On the other hand, ‘Giza843’ gave medium mean across the genotypes but it was the most drought tolerant variety. Negative correlation between the morphological traits and the drought tolerance in faba bean. Using SDS-PAGE analysis, optical differences were obtained between the varieties ‘Giza 843’ (drought tolerant) and ‘Giza 3’ (drought susceptible) in their protein patterns. Many protein bands were obtained in the protein pattern of the variety ‘Giza 843’ that were not obtained in the protein pattern of the variety ‘Giza 3’ while some protein bands were observed in the protein pattern of the variety ‘Giza 3’ that were not present in the protein pattern of the variety ‘Giza 843’. Significant association could be observed between morphological traits and biochemical markers.

Expression of ER quality control‐related genes in response to changes in BiP1 levels in developing rice endosperm

Binding protein (BiP) is the key chaperone involved in folding of secretory proteins such as seed storage proteins in the ER lumen. To obtain functional information about BiP1, a gene that is predominantly expressed during rice seed maturation, we generated several transgenic rice plants in which various levels of BiP1 protein accumulated in an endosperm-specific manner. Severe suppression (BiP1 KD) or significant over-expression (BiP1 OEmax) of BiP1 not only altered seed phenotype and the intracellular structure of endosperm cells, but also reduced seed storage protein content, starch accumulation and grain weight. Microarray and RT-PCR analyses indicated that expression of many chaperone and co-chaperone genes was induced in transgenic plants, with more prominent expression in the BiP1 KD line than in the BiP1 OEmax line. Transcriptional induction of most chaperones was observed in calli treated with dithiothreitol or tunicamycin, treatments that trigger ER stress, indicating that induction of the chaperone genes in transgenic rice was caused by an ER stress response. In transient assays using rice protoplasts, the ortholog (Os06g0622700) of the AtbZIP60 transcription factor was shown to be involved in activation of some chaperone genes. Slight increases in the BiP1 level compared with wild-type, accompanied by increased levels of calnexin and protein disulfide isomerase-like proteins, resulted in significant enhancement of seed storage protein content, without any change in intracellular structure or seed phenotype. Judicious modification of BiP1 levels in transgenic rice can provide suitable conditions for the production of secretory proteins by alleviating ER stress.

Genetic diversity of new maize hybrids based on SSR markers as compared with other molecular and biochemical markers

Genetic diversity of four new yellow single crosses, five new yellow three-way crosses, and five yellow inbred lines of maize (Zea mays L.) was studied using different molecular (SSR, ISSR, and RAPD) and biochemical markers (seed storage protein content). All markers were able to clearly separate the inbred lines in one cluster from the different types of hybrids. The correlation among the different types of molecular markers was moderately high according to the Mantel’s test (e.g. 0.67 between SSR and ISSR, 0.42 between SSR and RAPD, and 0.65 between ISSR and RAPD), indicating that the three techniques are efficient for evaluating genetic diversity in the maize genotypes. The correlation of biochemical markers (seed storage protein SDS-PAGE) with SSR, ISSR, and RAPD markers was 0.61, 0.74, and 0.48, respectively. It can be concluded that both molecular and biochemical markers are efficient to study the genetic diversity in maize. Among the different types of molecular markers, SSR is a more accurate marker-type because of its co-dominance and stability of results. It can also be said that biochemical and molecular markers are positively correlated and the correlation ranged between moderate to high. This could suggest using both marker types, separately or together, for genetic diversity studies in maize.

Employment of hordein subunit polymorphisms in establishing selection criteria for high quality malting barley (Hordeum vulgare L.)

Cereal seed storage proteins are encoded by complex multigene families and their subunit profiles are highly related to end-use qualities. Each fraction of albumin and hordein was extracted and its subunit profile was evaluated in related to malt and grain quality parameters. The purpose of this study was to provide selection criteria for high quality malting barley using grain and malt quality parameters and biochemical-genetic information. Grain and malt quality of 13 local adaptability test (LAT) lines were evaluated for malting process. A total of 16 germplasm accessions of high or low seed storage protein content were also evaluated for biochemicalgenetic analysis. The correlation coefficients among quality parameters were analyzed. Several important quality parameters in brewing process showed significant positive or negative correlations. Seed storage protein subunits of albumin and hordein of all tested lines and accessions were evaluated using 12% 1D SDS-PAGE. Scored data of protein subunit’s presence or absence was applied to Agglomerative Hierarchical Clustering (AHC) for statistical analysis and showed specific grouping patterns among tested lines. Clustered lines with subunit information were highly related with agricultural performance and grain and malt qualities. Based on the profiles of seed storage protein subunits, association of hordein subunit of 38, 43, and 65 kDa with high malt scored lines was found. The obtained results would provide improved selection criteria for high quality malting barley in the malting barley breeding program.

Effect of Nutrient Solution Concentration at the Heading Time on the Growth, Development, and Seed Storage Protein Content of Rice Plants in a Controlled Environment

Genetically modified (GM) rice varieties that store up pharmaceutical proteins in seeds have recently been developed. Since the pharmaceutical protein-encoding genes of these varieties are connected with the promoter of seed storage protein-encoding genes, the pharmaceutical protein content increases as the seed protein content increases. Rice varieties were grown in hydroponic culture at different nutrient solution concentrations at the heading time in a controlled environment. Emergence of non-productive stems was inhibited through an early reduction in the nutrient solution concentration due to accelerated translocation from the leaf blade, leaf sheath, and stem to the seed. Further, the seed storage protein composition was altered by regulating the concentration of the nutrient solution. When the nutrient solution concentration was increased just before heading occurred, translocation to the seeds as well as the generation of non-productive stems decreased. The total protein concentration of rice seeds was not increased by the treatments of nutrient solution concentration, however, it was greater in the plants grown in the present study than in plants grown in field cultivation. Seeds in which high concentrations of total protein and seed storage protein accumulate can be produced when the nutritional content is kept constant in hydroponic culture.

Variation and Distribution of Seed Storage Protein Content and Composition among Different Rice Varieties

The crude protein contents(PC) in 351 varieties were measured by near infrared spectroscopy(NIRS) and their distribution and classification were analyzed.The results showed that the average value of crude protein content in indica and japonica types were 13.2% and 12.2%,respectively,with an average of 12.42%.The ranges of those above were 10.8-16.8%,9.3-17.7%,and 9.3-17.7%,respectively.It elucidated that PC was higher in indica rice than that in japonica rice.The huge difference in ratios of varieties(lines) based on their PC showed the genetic disequilibrium between subspecies indica and japonica,for example,the ratio of japonica rice with low PC was eight times that of indica rice with low PC.According to the criterion classifying varieties with different protein contents,most of rice genotypes fell into the group with intermediate PC,and there was very small number of varieties with either high or low PC,especially with very high PC in japonica rice.However,we could find some extreme individuals whose PC were very high/low,such as those with high PC:forage rice,early maturity varieties and indica-japonica hybrid progenies close to indica in the subspecies of indica,or close to japonica in the subspecies of japonica;and those with low PC:some japonica rice(but the PC not low enough),some overseas germplasms in indica.Thus it was not impossible to find out extreme germplasms on PC from landrace,overseas germplasms or indica-japonica hybrid progenies etc.,which are fine basic materials in genetic and breeding research.From the results of SDS-PAGE analysis of the total seed storage proteins among some representative varieties,we could know that the seed storage protein composition was different among different types of rice genotypes.

Modification of Storage Protein Content and Quality in Legume Seeds

Abstract Worldwide, legume seed proteins represent a major source of amino acids for human and animal nutrition. However, they are notoriously deficient in sulphur-containing amino acids. Therefore attempts to overcome this imbalance are nutritionally relevant, and the concept of legume seed protein quality has been extended to technological and health-oriented aspects. This review focuses on the state-of-the-art of the conventional and innovative methodologies for the improvement of legume seed storage protein content and quality and also the constraints encountered. Modifications of storage protein quality can be achieved by conventional breeding and processing, and by genetic engineering. Various examples concerning selection of new lines by conventional breeding for the improvement of functional properties and modification of the sulphur content of the genetically engineered seeds are reported. It is becoming increasingly apparent that these two approaches are not mutually exclusive, rather they appea...