Striving for Stability in the Dough Mixing Quality of Spring Wheat under the Influence of Prolonged Heat and Drought

The effects of prolonged heat and drought stress and cool growing conditions on dough mixing quality traits of spring wheat (Triticum aestivum L.) were studied in fifty-six genotypes grown in 2017 and 2018 in southern Sweden. The mixing parameters evaluated by mixograph and the gluten protein characteristics studied by size exclusion high-performance liquid chromatography (SE-HPLC) in dough were compared between the two growing seasons which were very different in length, temperature and precipitation. The genotypes varying in gluten strength between the growing seasons (<= 5%, <= 12%, and <= 17%) from three groups (stable (S), moderately stable (MS), and of varying stability (VS)) were studied. The results indicate that most of the mixing parameters were more strongly impacted by the interaction between the group, genotype, and year than by their individual contribution. The excessive prolonged heat and drought did not impact the buildup and mixing time expressed as peak time and time 1-2. The gluten polymeric proteins (unextractable, %UPP; total unextractable, TOTU) and large unextractable monomeric proteins (%LUMP) were closely associated with buildup and water absorption in dough. Major significant differences were found in the dough mixing parameters between the years within each group. In Groups S and MS, the majority of genotypes showed the smallest variation in the dough mixing parameters responsible for the gluten strength and dough development between the years. The mixing parameters such as time 1-2, buildup, and peak time (which were not affected by prolonged heat and drought stress) together with the selected gluten protein parameters (%UPP, TOTU, and %LUMP) are essential components to be used in future screening of dough mixing quality in wheat in severe growing environments

Are ultrafine submicron sized gliadin fibrous materials suitable as bio-absorbents? Processing and post-treatment derived structures and functional properties

Gliadins were electrospun into ultrafine fibrous membrane-like materials to evaluate their processability and suitability as bio-absorbents. From a wide range of tested protein concentrations and processing conditions, 15 and 20% protein solutions were optimal to produce uniform fibers with size

Combating heavy metals in wheat grains under drought - is alien or ancient germplasm a solution to secure food and health?

Alien and ancient wheat germplasms have been utilized to combat diseases and improve yield performance under climate change. However, the potential risk of excessive heavy metal uptake with these germplasms has been less studied. In order to ensure food security, this study aimed to evaluate the levels of cadmium (Cd), lead (Pb) and mercury (Hg) in 30 wheat lines, including modern, old and wheat-rye introgression genotypes grown under three conditions i.e., control, early drought and late drought. The results of this study revealed a generally higher Cd grain accumulation in old and 1R genotypes than in the other genotype groups evaluated here, while old genotypes also showed an excess Pb grain concentration. The induced late drought resulted in an increased Cd uptake in wheat, leading to significantly elevated grain Cd concentration in modern, 1R, 1RS and 2R genotypes, while similar results were not obtained for the other heavy metals e.g. Pb or Hg. Specifically, an old genotype, 207, showed an extremely high Cd value across control and drought conditions. There was a greater genotypic variation in Pb concentration compared to Cd, while consistently high Hg concentrations were observed in several genotypes carrying 1R or 1RS. Some wheat-rye introgression genotypes, particularly those with the 3R chromosome, showed a low Cd accumulation across all treatments. The results from the present study pin-point the necessity of a rigorous assessment of heavy metal accumulation in wheat grain when utilizing ancient and alien genetic resources in breeding for disease resistance, and wheat resilience to environmental stress and climate change. Furthermore, the specific lines identified in this study with elevated heavy metal accumulation should be avoided in breeding programs. Additionally, mechanisms for the found differences in heavy metals accumulation among genotypes and treatments should be further revealed

Climate Change Impact on Wheat Performance-Effects on Vigour, Plant Traits and Yield from Early and Late Drought Stress in Diverse Lines

Global climate change is threatening wheat productivity; improved yield under drought conditions is urgent. Here, diverse spring-wheat lines (modern, old and wheat-rye introgressions) were examined in an image-based early-vigour assay and a controlled-conditions (Biotron) trial that evaluated 13 traits until maturity. Early root vigour was significantly higher in the old Swedish lines (root length 8.50 cm) and introgressed lines with 1R (11.78 cm) and 1RS (9.91 cm) than in the modern (4.20 cm) and 2R (4.67 cm) lines. No significant correlation was noted between early root and shoot vigour. A higher yield was obtained under early drought stress in the 3R genotypes than in the other genotype groups, while no clear patterns were noted under late drought. Evaluating the top 10% of genotypes in terms of the stress-tolerance index for yield showed that root biomass, grains and spikes per plant were accountable for tolerance to early drought, while 1000-grain weight and flag-leaf area were accountable for tolerance to late drought. Early root vigour was determined as an important focus trait of wheat breeding for tolerance to climate-change-induced drought. The responsible genes for the trait should be searched for in these diverse lines. Additional drought-tolerance traits determined here need further elaboration to identify the responsible genes

Diverse wheat lines to mitigate the effect of drought on end-use quality

Global climate change is causing an increasing number of drought events, which might impact the stability of wheat breadmaking quality. In this study, 73 spring wheat lines with diverse genetic backgrounds (modern, old, and wheat–rye introgression) were drought treated, and the grains were analyzed by high-performance liquid chromatography for protein composition traits related to breadmaking quality. The amount of total sodium dodecyl sulfate-extractable and -unextractable proteins (TOTE, which correlates to grain protein content) increased significantly under late drought, while no effect of early drought was found on the analyzed protein composition traits. Under control treatment, genotypes with 3R showed significantly higher TOTE than genotypes with 1R, 1RS, and 2R, indicating the potential role of 3R in increasing grain protein concentration. The lower percentage of sodium dodecyl sulfate-unextractable polymeric protein in the total polymeric protein (%UPP) found in 1R and 1RS genotypes as compared to modern and old genotypes suggested a gluten strength reduction induced by 1R and 1RS. Despite the negative yield–protein correlation found in this study, lines 252 (3R), 253 (3R), and 258 (2R) displayed the presence of germplasm with both high yield and protein concentration. The %UPP was found to be positively correlated to spike-size-related traits (grains per spike, grain weight per spike, and spike length) across all three treatments. Additionally, high and stable TOTE was mainly obtained in genotypes with 3R, while old genotypes showed dominant performance in %UPP. Thus, genes responsible for high and stable protein concentration and gluten strength should be explicitly searched among introgression lines with chromosome 3R and old Swedish cultivars, respectively

Green Chemistry to Modify Functional Properties of Crambe Protein Isolate-Based Thermally Formed Films

Proteins are promising precursors to be used in productionof sustainablematerials with properties resembling plastics, although protein modificationor functionalization is often required to obtain suitable productcharacteristics. Here, effects of protein modification were evaluatedby crosslinking behavior using high-performance liquid chromatography(HPLC), secondary structure using infrared spectroscopy (IR), liquidimbibition and uptake, and tensile properties of six crambe proteinisolates modified in solution before thermal pressing. The resultsshowed that a basic pH (10), especially when combined with the commonlyused, although moderately toxic, crosslinking agent glutaraldehyde(GA), resulted in a decrease in crosslinking in unpressed samples,as compared to acidic pH (4) samples. After pressing, a more crosslinkedprotein matrix with an increase in beta-sheets was obtained inbasic samples compared to acidic samples, mainly due to the formationof disulfide bonds, which led to an increase in tensile strength,and liquid uptake with less material resolved. A treatment of pH 10+ GA, combined either with a heat or citric acid treatment, did notincrease crosslinking or improve the properties in pressed samples,as compared to pH 4 samples. Fenton treatment at pH 7.5 resulted ina similar amount of crosslinking as the pH 10 + GA treatment, althoughwith a higher degree of peptide/irreversible bonds. The strong bondformation resulted in lack of opportunities to disintegrate the proteinnetwork by all extraction solutions tested (even for 6 M urea + 1%sodium dodecyl sulfate + 1% dithiothreitol). Thus, the highest crosslinkingand best properties of the material produced from crambe protein isolateswere obtained by pH 10 + GA and pH 7.5 + Fenton, where Fenton is agreener and more sustainable solution than GA. Therefore, chemicalmodification of crambe protein isolates is effecting both sustainabilityand crosslinking behavior, which might have an effect on product suitability

Alien introgression to wheat for food security: functional and nutritional quality for novel products under climate change

Crop yield and quality has increased globally during recent decades due to plant breeding, resulting in improved food security. However, climate change and shifts in human dietary habits and preferences display novel pressure on crop production to deliver enough quantity and quality to secure food for future generations. This review paper describes the current state-of-the-art and presents innovative approaches related to alien introgressions into wheat, focusing on aspects related to quality, functional characteristics, nutritional attributes, and development of novel food products. The benefits and opportunities that the novel and traditional plant breeding methods contribute to using alien germplasm in plant breeding are also discussed. In principle, gene introgressions from rye have been the most widely utilized alien gene source for wheat. Furthermore, the incorporation of novel resistance genes toward diseases and pests have been the most transferred type of genes into the wheat genome. The incorporation of novel resistance genes toward diseases and pests into the wheat genome is important in breeding for increased food security. Alien introgressions to wheat from e.g. rye and Aegilops spp. have also contributed to improved nutritional and functional quality. Recent studies have shown that introgressions to wheat of genes from chromosome 3 in rye have an impact on both yield, nutritional and functional quality, and quality stability during drought treatment, another character of high importance for food security under climate change scenarios. Additionally, the introgression of alien genes into wheat has the potential to improve the nutritional profiles of future food products, by contributing higher minerals levels or lower levels of anti-nutritional compounds into e.g., plant-based products substituting animal-based food alternatives. To conclude, the present review paper highlights great opportunities and shows a few examples of how food security and functional-nutritional quality in traditional and novel wheat products can be improved by the use of genes from alien sources, such as rye and other relatives to wheat. Novel and upcoming plant breeding methods such as genome-wide association studies, gene editing, genomic selection and speed breeding, have the potential to complement traditional technologies to keep pace with climate change and consumer eating habits

Impact of Combined Drought and Heat Stress and Nitrogen on Winter Wheat Productivity and End-Use Quality

Water deficit and heat stress are the main abiotic stresses affecting the yield and quality of winter wheat. The increasing frequency of the simultaneous occurrence of these two stresses might threaten global food security and drives the need to breed resilient high-quality cultivars. The aim of this study was to evaluate the grain yield, quality and gluten protein characteristics in 50 winter wheat cultivars and breeding lines during the harvest years of 2018 and 2019. The yield and grain quality components were affected more severely by the combined heat and drought in 2019 than the drought in 2018. Two nitrogen (N) fertilization regimes were studied, sustainable (S, 15/100/30 kg N ha(-1)) and high-input (HI, 15/100/100 kg N ha(-1)). The yield was higher in HI trials compared to S trials by 2.2 t ha(-1) in 2018 and by 2.4 t ha(-1) in 2019. Higher protein content and sedimentation volume and lower yield, test weight and starch content were observed under combined heat and drought stress in 2019 compared to 2018. Genotypes containing the Glu-D1 x5-y10 allele exhibited the higher amounts of unextractable polymeric proteins (%UPP = 58.5%) in gluten studied by size exclusion liquid chromatography (SE-HPLC) as compared to Glu-D1 x2-y12 allele (%UPP = 54.3%). Genotype was the main determinant of gluten protein characteristics regardless of the nitrogen application and the abiotic stress conditions. The results suggest that the relatively mild drought and heat events in Lithuania might not threaten gluten quality in the future; however, breeding efforts should be directed towards improved drought and heat stress resistance to ensure stable wheat productivity in the region