Understanding Wheat Starch Metabolism in Properties, Environmental Stress Condition, and Molecular Approaches for Value-Added Utilization

Effect of fenugreek (Trigonella foenum-graecum L.) seed extract on glycemic index, in vitro digestibility, and physical characterization of wheat (Triticum aestivum L.) starch

Diabetes is a major health concern and is approaching epidemic proportions worldwide. In 2021, diabetes mellitus was responsible for 6.7 million deaths across the globe. Mortality due to diabetes is predicted to rise nearly 10-fold by 2030 and 783 million by 2045. Wheat starch, which constitutes about 70% of the endosperm, is a key component of wheat grain. The rapid hydrolysis of wheat starch can result in elevated postprandial glucose levels, leading to diabetes. The increase in blood glucose levels is primarily due to carbohydrate hydrolysis, catalyzed by the enzymes α-amylase and α-glucosidase. Although various medications are available for treating diabetes, most of them are costly and may lead to adverse effects. Natural herbs like fenugreek are recommended in traditional medicine for regulating blood glucose levels. This investigation aimed to study the effect of fenugreek seed extract (FSE) on in vitro starch hydrolysis by pancreatic α-amylase and the ultrastructure of starch. Wheat cultivars were characterized for their total starch, amylose content, and resistant starch content, and were screened for their predicted glycemic index. Microscopic studies were conducted to analyze the size and shape of starch granules and to compare native starch with starch treated with FSE. Significant inhibition of enzymatic starch hydrolysis was observed with FSE, with the maximum inhibitory effect caused by 0.2% FSE. These findings suggest that fenugreek could play a role in controlling blood glucose levels by reducing wheat starch hydrolysis and could be effective in managing diabetes.

Hydrogen sulfide and ethylene regulate photosynthesis, sugar metabolism, and tolerance to heat stress in the presence of sulfur in rice

Heat stress impacts photosynthesis and carbohydrate metabolism, challenging food security. To comprehend the mechanisms of thermotolerance, we examined the role of ethylene (ET) and hydrogen sulfide (H2S) with or without sulfur (S) in rice (Oryza sativa L.). Both ET and H2S promoted heat stress tolerance more conspicuously in the presence of S, restoring the balance between carbon assimilation and utilization. The enhanced photosynthesis in ET and H2S-treated plants under heat stress was linked with increased relative expression of Rubisco subunits rbcS and rbcL and carbohydrate metabolizing, including Sucrose Synthase 2 (SuSy2) and Sucrose transport 1 (SUT1). Notably, the H2S application showed the highest increase of 2.3, 3.2, 3.0, and 2.4-fold expression of the rbcS, rbcL, SuSy2, and SUT1, respectively, compared to the heat stress alone. The application of H2S with S more prominently increased starch content, total soluble sugar, and soluble invertase activity by 59.3%, 35.7%, and 25.9%, and also activity of soluble starch synthase and granule-bound starch synthase by 47.2% and 32.8%, respectively, compared to heat-stressed plants. The treatment (H2S plus S) elevated cysteine and GSH content and the activity of the antioxidant enzymes to maintain cellular redox potential under heat stress. These observed tolerance responses were less pronounced in plants treated with hypotaurine (HT; H2S scavenger) than those treated with norbornadiene (NBD; ET inhibitor), underscoring the superior role of H2S over ET in mitigating heat stress. The present study's findings explain that H2S is crucial for the ET-mediated response in augmenting photosynthesis and heat stress tolerance in rice.

Characterization of putative calcium-dependent protein kinase-1 (TaCPK-1) gene: hubs in signalling and tolerance network of wheat under terminal heat

Calcium-dependent protein kinase (CDPK) is member of one of the most important signalling cascades operating inside the plant system due to its peculiar role as thermo-sensor. Here, we identified 28 full length putative CDPKs from wheat designated as TaCDPK (1-28). Based on digital gene expression, we cloned full length TaCPK-1 gene of 1691 nucleotides with open reading frame (ORF) of 548 amino acids (accession number OP125853). The expression of TaCPK-1 was observed maximum (3.1-fold) in leaf of wheat cv. HD2985 (thermotolerant) under T2 (38 ± 3 °C, 2 h), as compared to control. A positive correlation was observed between the expression of TaCPK-1 and other stress-associated genes (MAPK6, CDPK4, HSFA6e, HSF3, HSP17, HSP70, SOD and CAT) involved in thermotolerance. Global protein kinase assay showed maximum activity in leaves, as compared to root, stem and spike under heat stress. Immunoblot analysis showed abundance of CDPK protein in wheat cv. HD2985 (thermotolerant) in response to T2 (38 ± 3 °C, 2 h), as compared to HD2329 (thermosusceptible). Calcium ion (Ca2+), being inducer of CDPK, showed strong Ca-signature in the leaf tissue (Ca-622 ppm) of thermotolerant wheat cv. under heat stress, whereas it was minimum (Ca-201 ppm) in spike tissue. We observed significant variations in the ionome of wheat under HS. To conclude, TaCPK-1 plays important role in triggering signaling network and in modulation of HS-tolerance in wheat.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03989-6.

A Review of the Impact of Starch on the Quality of Wheat-Based Noodles and Pasta: From the View of Starch Structural and Functional Properties and Interaction with Gluten

Starch, as a primary component of wheat, plays a crucial role in determining the quality of noodles and pasta. A deep understanding of the impact of starch on the quality of noodles and pasta is fundamentally important for the industrial progression of these products. The starch structure exerts an influence on the quality of noodles and pasta by affecting its functional attributes and the interaction of starch-gluten proteins. The effects of starch structure (amylopectin structure, amylose content, granules size, damaged starch content) on the quality of noodles and pasta is discussed. The relationship between the functional properties of starch, particularly its swelling power and pasting properties, and the texture of noodles and pasta is discussed. It is important to note that the functional properties of starch can be modified during the processing of noodles and pasta, potentially impacting the quality of the end product, However, this aspect is often overlooked. Additionally, the interaction between starch and gluten is addressed in relation to its impact on the quality of noodles and pasta. Finally, the application of exogenous starch in improving the quality of noodles and pasta is highlighted.

Structural and physicochemical effects on the starch quality of the high-quality wheat genotype caused by delayed sowing

Background

Bread wheat is one of the most important food crops associated with ensuring food security and human nutritional health. The starch quality is an important index of high-quality wheat. It is affected by a complex series of factors; among which, suitable sowing time is a key factor.

Aim and methods

To analyze the integrative effects of sowing time on the starch quality of high-quality wheat, in the present study, we selected a high-quality bread wheat cultivar Jinan 17 and investigated the effect of different sowing times on the starch properties and the related genes by analyzing X-ray diffraction patterns, apparent amylose content, thermal properties, pasting properties, in vitro starch digestibility, and qRT-PCR. Meanwhile, we also investigated the agronomic and yield performance that may be associated with the starch properties.

Results

Delayed sowing had little effect on starch crystalline morphology, but there was a tendency to reduce the formation of crystals within wheat starch granules: (1) delayed sowing for 15 days altered the thermal properties of starch, including onset, peak and termination temperatures, and enthalpy changes; (2) delayed sowing for 30 days changed the thermal characteristics of starch relatively insignificant; (3) significant differences in pasting characteristics occurred: peak viscosity and hold-through viscosity increased, while final viscosity, breakdown viscosity, and setback viscosity tended to increase and then decrease, suggesting that delayed sowing caused changes in the surface of the starch granules resulting in a decrease in digestibility. Analysis of related genes showed that several key enzymes in starch biosynthesis were significantly affected by delayed sowing, leading to a reduction in apparent straight-chain starch content. In addition to starch properties, thousand-kernel weight also increased under delayed sowing conditions compared with normal sowing.

Conclusion

The impact of delayed sowing on starch quality is multifaceted and complex, from the fine structure, and functional properties of the starch to the regulation of key gene expression. Our study holds significant practical value for optimizing wheat planting management and maximizing the potential in both quality and yield.

Recent advances in modified starch based biodegradable food packaging: A review

This study reviews the importance of resistant starch (RS) as the polymer of choice for biodegradable food packaging and highlights the RS types and modification methods for developing RS from native starch (NS). NS is used in packaging because of its vast availability, low cost and film forming capacity. However, application of starch is restricted due to its high moisture sensitivity and hydrophilic nature. The modification of NS into RS improves the film forming characteristics and extends the applications of starch into the formulation of packaging. The starch is blended with other bio-based polymers such as guar, konjac glucomannan, carrageenan, chitosan, xanthan gum and gelatin as well as active ingredients such as nanoparticles (NPs), plant extracts and essential oils to develop hybrid biodegradable packaging with reduced water vapor permeability (WVP), low gas transmission, enhanced antimicrobial activity and mechanical properties. Hybrid RS based active packaging is well known for its better film forming properties, crystalline structures, enhanced tensile strength, water resistance and thermal properties. This review concludes that RS, due to its better film forming ability and stability, can be utilized as polymer of choice in the formulation of biodegradable packaging.

Investigation of the in vitro biological activities of polyethylene glycol-based thermally stable polyurethane elastomers

The intense urge to replace conventional polymers with ecofriendly monomers is a step towards green products. The novelty of this study is the extraction of starch from the biowaste of wheat bran (WB) and banana peel (BP) for use as a monomer in the form of chain extenders. For the synthesis of polyurethane (PU) elastomers, polyethylene glycol (PEG) bearing an average molecular weight Mn = 1000 g mol-1 was used as a macrodiol, which was reacted with isophorone diisocyanate (IPDI) to develop NCO-terminated prepolymer chains. These prepolymer chains were terminated with chain extenders. Two series of linear PU elastomers were prepared by varying the concentration of chain extenders (0.5-2.5 mol%), inducing a variation of 40 to 70 wt% in the hard segment (HS). Fourier-transform infrared (FTIR) spectroscopy confirmed the formation of urethane linkages. Thermal gravimetric analysis (TGA) showed a thermal stability of up to 250 °C. Dynamic mechanical analysis (DMA) revealed a storage modulus (E') of up to 140 MPa. Furthermore, the hemolytic activities of up to 8.97 ± 0.1% were recorded. The inhibition of biofilm formation was investigated against E. coli and S. aureus (%), which was supported by phase contrast microscopy.

Effects of Post-Anthesis Irrigation on the Activity of Starch Synthesis-Related Enzymes and Wheat Grain Quality under Different Nitrogen Conditions

To develop optimal management strategies for water and nitrogen fertilizer application in winter wheat cultivation, we conducted a potted experiment to investigate the effects of different irrigation levels and nitrogen fertilizer treatments on the activity of starch synthesis-related enzymes and the grain quality of winter wheat. The potted experiment consisted of three irrigation levels, with the lower limits set at 50-55% (I0), 60-65% (I1), and 70-75% (I2) of the field capacity. In addition, four levels of nitrogen fertilizer were applied, denoted as N0 (0 kg N hm-2), N1 (120 kg N hm-2), N2 (240 kg N hm-2), and N3 (300 kg N hm-2), respectively. The results revealed the significant impacts of irrigation and nitrogen treatments on the activities of key starch-related enzymes, including adenosine diphosphoglucose pyrophosphrylase (ADPG-PPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS), and starch branching enzymes (SBE) in wheat grains. These treatments also influenced the starch content, amylopectin content, and, ultimately, wheat yield. In summary, our findings suggest that maintaining irrigation at a lower limit of 60% to 65% of the field capacity and applying nitrogen fertilizer at a rate of 240 kg hm-2 is beneficial for achieving both high yield and high quality in winter wheat cultivation.

Advances in bread wheat production through CRISPR/Cas9 technology: a comprehensive review of quality and other aspects

MAIN CONCLUSION

This review provides a comprehensive overview of the CRISPR/Cas9 technique and the research areas of this gene editing tool in improving wheat quality. Wheat (Triticum aestivum L.), the basic nutrition for most of the human population, contributes 20% of the daily energy needed because of its, carbohydrate, essential amino acids, minerals, protein, and vitamin content. Wheat varieties that produce high yields and have enhanced nutritional quality will be required to fulfill future demands. Hexaploid wheat has A, B, and D genomes and includes three like but not identical copies of genes that influence important yield and quality. CRISPR/Cas9, which allows multiplex genome editing provides major opportunities in genome editing studies of plants, especially complicated genomes such as wheat. In this overview, we discuss the CRISPR/Cas9 technique, which is credited with bringing about a paradigm shift in genome editing studies. We also provide a summary of recent research utilizing CRISPR/Cas9 to investigate yield, quality, resistance to biotic/abiotic stress, and hybrid seed production. In addition, we provide a synopsis of the laboratory experience-based solution alternatives as well as the potential obstacles for wheat CRISPR studies. Although wheat's extensive genome and complicated polyploid structure previously slowed wheat genetic engineering and breeding progress, effective CRISPR/Cas9 systems are now successfully used to boost wheat development.

Phytochemical, Morphological, and Physiological Variation in Different Ajowan (Trachyspermum ammi L.) Populations as Affected by Salt Stress, Genotype × Year Interaction and Pollination System

In the present research, 28 populations of ajowan (Trachyspermum ammi L.) were evaluated for agro-morphological traits and essential oil yield in two consecutive years. Then, selected ajowan populations from these two years were used for further morphophysiological and biochemical studies under different salinity levels (control, 60, 90, and 120 mM NaCl). The main components of the oil were thymol (32.7-54.29%), γ-terpinene (21.71-32.81%), and p-cymene (18.74-26.16%). Salt stress caused an increase in essential oil content in the Esfahfo and Qazvin populations. The highest total phenolic and flavonoid contents were found in the Arak population grown in 60 mM NaCl (183.83 mg TAE g^-1 DW) and the Yazd population grown in 90 mM NaCl (5.94 mg QE g^-1 DW). Moreover, the Yazd population exhibited the strongest antioxidant activity based on DPPH (IC₅₀ = 1566 µg/mL) under 60 mM NaCl and the highest reducing power (0.69 nm) under 120 mM NaCl. The results revealed that low and moderate salt stress improves the phytochemicals of ajowan seeds, which are useful for pharmaceutical and food applications. In this research, some morphological traits, as well as essential oil yield, were evaluated in open pollinated versus self-pollinated plants. As a result, plant height, number of flowering branches, and crown diameter significantly decreased in some populations, while a significant increase was obtained for number of flowers per umbel and seed numbers per umbel. Finally, self-pollination of ajowan might provide new insights for further breeding programs to increase oil or thymol content in ajowan.

Starch-based controlled release fertilizers: A review

Starch, as a widely available renewable resource, has the potential to be used in the production of controlled-release fertilizers (CRFs) that support sustainable agriculture. These CRFs can be formed by incorporating nutrients through coating or absorption, or by chemically modifying the starch to enhance its ability to carry and interact with nutrients. This review examines the various methods of creating starch-based CRFs, including coating, chemical modification, and grafting with other polymers. In addition, the mechanisms of controlled release in starch-based CRFs are discussed. Overall, the potential benefits of using starch-based CRFs in terms of resource efficiency and environmental protection are highlighted.

The functional implications of high-amylose wholegrain wheat flours: An in vitro digestion and fermentation approach combined with metabolomics

Wheat flour is one of the most prevalent foodstuffs for human consumption, and novel strategies are underway to enhance its nutritional properties. This work evaluated wholegrain flours from bread wheat lines with different amylose/amylopectin ratios through in vitro starch digestion and large intestine fermentation. High-amylose flours presented a higher resistant starch content and lower starch hydrolysis index. Moreover, UHPLC-HRMS metabolomics was carried out to determine the profile of the resulting in vitro fermentates. The multivariate analysis highlighted distinctive profiles between the flours derived from the different lines compared to the wild type. Peptides, glycerophospholipids, polyphenols, and terpenoids were identified as the main markers of the discrimination. The high-amylose flour fermentates showed the richest bioactive profile, containing stilbenes, carotenoids, and saponins. Present findings pave the way toward applying high-amylose flours to design novel functional foods.

Impact of Foliar Application of ZnO and Fe3O4 Nanoparticles on Seed Yield and Physio-Biochemical Parameters of Cucumber (Cucumis sativus L.) Seed under Open Field and Protected Environment vis a vis during Seed Germination

Nutritionally rich cucumber seeds remain in demand in the agricultural, health and cosmetic sectors as they are essential for a successful crop stand establishment and seed-based products. However, the production of cucumber seeds is impeded by source limitation and nutrient deficiency. The foliar application of micronutrients can supplement this deficiency and overcome the physiological setback. An experiment was undertaken to compare the impacts of the foliar application of Fe and Zn, as nanoparticles and fertilizers, on the yield and seed quality of cucumber under open and protected environments. A foliar spray of nano-ZnO (ZnNPs) and nano-Fe3O4 (FeNPs) at 100, 200 and 300 mg L-1, as well as ZnSO4 and FeSO4 as fertilizer (0.5%), was conducted at the vegetative stage and pre- and post-flowering stages. The NPs had a greater efficacy in an open field than in the protected (naturally ventilated poly house) environment. The application of both NPs increased seed yield (51.7-52.2%), total chlorophyll content (15.9-17.3%) and concentration of Zn and Fe in the fruit and the seed, by 2.0-58.5% and 5.0-30.5%, respectively. A significant increase in starch, soluble proteins, soluble sugars and oil content was observed in the seeds from the NP treated plants. NP treatment also enhanced the germination-related parameters, such as percent germination (16.8-17.0%), rate of germination (18.0-22.2%) and seedling vigor (59.8-72.6%). The biochemical characterization showed a significant improvement in the seed water uptake and the activity of hydrolytic enzymes (amylase and protease) in the germinating seed. The involvement of reactive oxygen species (superoxide anion and hydrogen peroxide) and antioxidant enzymes (Superoxide dismutase, Catalase and Peroxidase) in the germination process was indicated by an increase in their activities in the seeds from NP treated plants. Hence, the study proposes the potential benefit of the foliar application of 300 mg L-1 ZnNPs and 200 mg L-1 FeNPs at crucial stages of plant growth to improve the yield and seed quality in cucumbers.

Transcriptome and Proteome Co-Profiling Offers an Understanding of Pre-Harvest Sprouting (PHS) Molecular Mechanisms in Wheat (Triticum aestivum)

While wheat (Triticum aestivum L.) is a widely grown and enjoyed crop, the diverse and complex global situation and climate are exacerbating the instability of its supply. In particular, pre-harvest sprouting (PHS) is one of the major abiotic stresses that frequently occurs due to irregular climate conditions, causing serious damage to wheat and its quality. In this study, transcriptomic analysis with RNA-seq and proteomic analysis with LC-MS/MS were performed in PHS-treated spikes from two wheat cultivars presenting PHS sensitivity and tolerance, respectively. A total of 13,154 differentially expressed genes (DEGs) and 706 differentially expressed proteins (DEPs) were identified in four comparison groups between the susceptible/tolerant cultivars. Gene function and correlation analysis were performed to determine the co-profiled genes and proteins affected by PHS treatment. In the functional annotation of each comparative group, similar functions were confirmed in each cultivar under PHS treatment; however, in Keumgang PHS+7 (K7) vs. Woori PHS+7 (W7), functional annotations presented clear differences in the "spliceosome" and "proteasome" pathways. In addition, our results indicate that alternative splicing and ubiquitin-proteasome support the regulation of germination and seed dormancy. This study provides an advanced understanding of the functions involved in transcription and translation related to PHS mechanisms, thus enabling specific proposals for the further analysis of germination and seed dormancy mechanisms and pathways in wheat.