Elevating optimal human nutrition to a central goal of plant breeding and production of plant-based foods

From 'Farm to Fork': Exploring the Potential of Nutrient-Rich and Stress-Resilient Emergent Crops for Sustainable and Healthy Food in the Mediterranean Region in the Face of Climate Change Challenges

In the dynamic landscape of agriculture and food science, incorporating emergent crops appears as a pioneering solution for diversifying agriculture, unlocking possibilities for sustainable cultivation and nutritional bolstering food security, and creating economic prospects amid evolving environmental and market conditions with positive impacts on human health. This review explores the potential of utilizing emergent crops in Mediterranean environments under current climate scenarios, emphasizing the manifold benefits of agricultural and food system diversification and assessing the impact of environmental factors on their quality and consumer health. Through a deep exploration of the resilience, nutritional value, and health impacts of neglected and underutilized species (NUS) such as quinoa, amaranth, chia, moringa, buckwheat, millet, teff, hemp, or desert truffles, their capacity to thrive in the changing Mediterranean climate is highlighted, offering novel opportunities for agriculture and functional food development. By analysing how promoting agricultural diversification can enhance food system adaptability to evolving environmental conditions, fostering sustainability and resilience, we discuss recent findings that underscore the main benefits and limitations of these crops from agricultural, food science, and health perspectives, all crucial for responsible and sustainable adoption. Thus, by using a sustainable and holistic approach, this revision analyses how the integration of NUS crops into Mediterranean agrifood systems can enhance agriculture resilience and food quality addressing environmental, nutritional, biomedical, economic, and cultural dimensions, thereby mitigating the risks associated with monoculture practices and bolstering local economies and livelihoods under new climate scenarios.

Harmony in Motion: Unraveling the Nexus of Sports, Plant-Based Nutrition, and Antioxidants for Peak Performance

The intricate interplay between plant-based nutrition, antioxidants, and their impact on athletic performance forms the cornerstone of this comprehensive review. Emphasizing the pivotal importance of dietary choices in the realm of sports, this paper sets the stage for an in-depth exploration of how stress and physical performance are interconnected through the lens of nutrition. The increasing interest among athletes in plant-based diets presents an opportunity with benefits for health, performance, and recovery. It is essential to investigate the connection between sports, plants, and antioxidants. Highlighting the impact of nutrition on recovery and well-being, this review emphasizes how antioxidants can help mitigate oxidative stress. Furthermore, it discusses the growing popularity of plant-based diets among athletes. It elaborates on the importance of antioxidants in combating radicals addressing stress levels while promoting cellular health. By identifying rich foods, it emphasizes the role of a balanced diet in ensuring sufficient intake of these beneficial compounds. Examining stress within the context of sports activities, this review provides insights into its mechanisms and its impact on athletic performance as well as recovery processes. This study explores the impact of plant-based diets on athletes including their types, potential advantages and challenges. It also addresses the drawbacks of relying on plant-based diets, concerns related to antioxidant supplementation and identifies areas where further research is needed. Furthermore, the review suggests directions for research and potential innovations in sports nutrition. Ultimately it brings together the aspects of sports, plant-based nutrition, and antioxidants to provide a perspective for athletes, researchers and practitioners. By consolidating existing knowledge, it offers insights that can pave the way for advancements in the ever-evolving field of sports nutrition.

Genomic prediction of seed nutritional traits in biparental families of oat (Avena sativa)

Selection for more nutritious crop plants is an important goal of plant breeding to improve food quality and contribute to human health outcomes. While there are efforts to integrate genomic prediction to accelerate breeding progress, an ongoing challenge is identifying strategies to improve accuracy when predicting within biparental populations in breeding programs. We tested multiple genomic prediction methods for 12 seed fatty acid content traits in oat (Avena sativa L.), as unsaturated fatty acids are a key nutritional trait in oat. Using two well-characterized oat germplasm panels and other biparental families as training populations, we predicted family mean and individual values within families. Genomic prediction of family mean exceeded a mean accuracy of 0.40 and 0.80 using an unrelated and related germplasm panel, respectively, where the related germplasm panel outperformed prediction based on phenotypic means (0.54). Within family prediction accuracy was more variable: training on the related germplasm had higher accuracy than the unrelated panel (0.14-0.16 and 0.05-0.07, respectively), but variability between families was not easily predicted by parent relatedness, segregation of a locus detected by a genome-wide association study in the panel, or other characteristics. When using other families as training populations, prediction accuracies were comparable to the related germplasm panel (0.11-0.23), and families that had half-sib families in the training set had higher prediction accuracy than those that did not. Overall, this work provides an example of genomic prediction of family means and within biparental families for an important nutritional trait and suggests that using related germplasm panels as training populations can be effective.

Rapid screening of sixty potato cultivars for starch profiles to address a consumer glycemic dilemma

Potatoes are a dietary staple consumed by a significant portion of the world, providing valuable carbohydrates and vitamins. However, most commercially produced potatoes have a high content of highly branched amylopectin starch, which generally results in a high glycemic index (GI). Consumption of foods with high levels of amylopectin elicit a rapid spike in blood glucose levels, which is undesirable for individuals who are pre-diabetic, diabetic, or obese. Some cultivars of potatoes with lower amylopectin levels have previously been identified and are commercially available in niche markets in some countries, but they are relatively unavailable in the United States and Latin America. The high glycemic index of widely available potatoes presents a problematic "consumer's dilemma" for individuals and families that may not be able to afford a better-balanced, more favorable diet. Some native communities in the Andes (Bolivia, Chile, and Peru) reportedly embrace a tradition of providing low glycemic tubers to people with obesity or diabetes to help people mitigate what is now understood as the negative effects of high blood sugar and obesity. These cultivars are not widely available on a global market. This study examines 60 potato cultivars to identify potatoes with low amylopectin. Three independent analyses of potato starch were used: microscopic examination of granule structure, water absorption, and spectrophotometric analysis of iodine complexes to identify potato cultivars with low amylopectin Differences among cultivars tested were detected by all three types of analyses. The most promising cultivars are Huckleberry Gold, Muru, Multa, Green Mountain, and an October Blue x Colorado Rose cross. Further work is necessary to document the ability of these low amylopectin cultivars to reduce blood glucose spike levels in human subjects.

Greek Landrace Flours Characteristics and Quality of Dough and Bread

Besides organic growing, ancient wheats and landraces are attracting the attention of scientists who are reassessing the healthy and dietary properties attributed to them by popular tradition. A total of eleven wheat flours and whole meal samples were analyzed, of which, nine originated from the organic farming of five Greek landraces (one einkorn, one emmer, two durum, and one soft wheat) and a commercial organically grown emmer cultivar. Two commercial conventional flours of 70% and 100% extraction rate were examined for comparison purposes. Chemical composition, micronutrients, phenolic profile, and quantification, and antioxidant activity of all samples were determined. Moreover, dough rheology and breadmaking quality were studied; Flours from local landraces were higher in micronutrients, phenolic content, and antioxidant activity than the commercial samples. The 90% extraction flour of the landrace, besides the highest protein content (16.62%), exhibited the highest content of phenolic acids (19.14 μg/g of flour), whereas the commercial refined emmer flour was the lowest (5.92 μg/g of flour). The same milling of the einkorn landrace also showed a higher specific volume (1.9 mL/g vs. 1.7 mL/g) and lower bread crumb firmness than the whole meal commercial emmer sample (33.0 N vs. 44.9 N). The results of this study showed that the examined Greek wheat landraces could be considered as a possible source of microelements, phenolics, and antioxidants with a beneficial effect in human health, and by using an appropriate breadmaking procedure, they could produce high-quality breads.

Comparative Compositions of Grain of Bread Wheat, Emmer and Spelt Grown with Different Levels of Nitrogen Fertilisation

Five cultivars of bread wheat and spelt and three of emmer were grown in replicate randomised field trials on two sites for two years with 100 and 200 kg nitrogen fertiliser per hectare, reflecting low input and intensive farming systems. Wholemeal flours were analysed for components that are suggested to contribute to a healthy diet. The ranges of all components overlapped between the three cereal types, reflecting the effects of both genotype and environment. Nevertheless, statistically significant differences in the contents of some components were observed. Notably, emmer and spelt had higher contents of protein, iron, zinc, magnesium, choline and glycine betaine, but also of asparagine (the precursor of acrylamide) and raffinose. By contrast, bread wheat had higher contents of the two major types of fibre, arabinoxylan (AX) and β-glucan, than emmer and a higher AX content than spelt. Although such differences in composition may be suggested to result in effects on metabolic parameters and health when studied in isolation, the final effects will depend on the quantity consumed and the composition of the overall diet.

Phytochemical Components and Human Health Effects of Old versus Modern Italian Wheat Varieties: The Case of Durum Wheat Senatore Cappelli

The Mediterranean diet has significant beneficial health effects and wheat is a major component of the Mediterranean diet, mainly in the form of bread and pasta. Modern wheat generally refers to varieties that were developed after the introduction of dwarfing genes in the 1950s, while old varieties are considered those developed before that time. Research findings on Italian wheat varieties showed that the total polyphenol content in both old and modern durum and soft wheat varieties are similar; but the old varieties have a higher number of polyphenols and of isomer forms. In particular, the durum wheat Senatore Cappelli genotype shows a very high variety of polyphenolic components. Recent studies have demonstrated healthy cardiovascular effects (favorable changes of atherosclerosis markers such as lipid parameters and hemorheological variables) as well as a marked reduction in gastrointestinal and extra-intestinal symptoms in non-celiac gluten sensitivity subjects with the consumption of pasta obtained by old durum wheat Senatore Cappelli variety, even though this type of wheat contains high amounts of gluten. In conclusion, old wheat Italian varieties, and in particular the Senatore Cappelli genotype, are characterized by multiple nutraceutical specificities that could suggest their use for health-promoting purposes. Additional research is needed to confirm these findings, focusing attention also on the effect of different environments and years.

Quality Evaluation Indices for Soybean Oil in Relation to Cultivar, Application of N Fertiliser and Seed Inoculation with Bradyrhizobium japonicum

Soybean ranks second in production and consumption of vegetable oils worldwide and these are expected to continue to increase. The suitability of soybean oil for specific uses is determined by the fatty acid composition from which a number of indices and indicators can be calculated. The aim of this study was to evaluate the indices of nutritional and health-promoting fat in seeds of soybean cultivars grown in 2016–2019 under the influence of varying doses of N and inoculation with Bradyrhizobium japonicum. Omega 3 and Omega 6, unsaturated fatty acids (UFA), saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), index of desirable fatty acids (DFA), sum of hypercholesterolemic fatty acids (OFA), index of atherogenicity (AI), index of thrombogenicity (TI), oleic desaturation ratio (ODR), linoleic desaturation ratio (LDR), calculated oxidizability value (COX) and the hypocholesterolemic/hypercholesterolemic ratio (HH), saturation fat index (S/P) and ALA/LA, OL/(LA+ALA) ratios and the consumer index (CI) were included. Fat quality indices for soybean seeds were strongly determined by weather conditions. Seeds of the cv. Aldana contained higher amounts of Omega 6 and featured more favourable MUFA/PUFA and OL/(LA+ALA) ratios, while the seeds of the cv. Annushka had more favourable CI and higher ODR, COX and S/P indices. No important differences were observed regarding the effect of nitrogen dose and seed inoculation on the formation of the DFA, OFA, HH, AI, TI and CI indices. The value of the S/P index suggests that higher nitrogen rates (60 kg∙ha−1) and the lack of inoculation treatment produce seeds with a more favourable dietary fatty acid balance.

Nutritional prospects of jackfruit and its potential for improving dietary diversity in Uganda

Objective

A sustainable way of providing essential nutrients from crops for the poor and undernourished is biofortification, through plant breeding. This study characterised the intraspecific variation of selected nutritional elements in the flakes and seeds of Ugandan jackfruit (Artocarpus heterophyllus) plus the phytochemical composition of leaves. The overall aim was to explore possibilities of selecting for varieties that are higher in selected essential nutrients. Selecting for nutrient dense crops has been mostly done for annual agricultural crops, and rarely for perennial fruit trees.

Results

Uganda’s Jackfruit has high macronutrients, especially magnesium and calcium. This study revealed that the amounts of these macronutrients were higher than those found in commonly consumed fruits, giving jackfruit a nutritional advantage with respect to these nutrients. The varieties sampled also differed significantly (p < 0.01) for some nutrients such as vitamin C, crude fat, crude fibre, total soluble solids and juice yield, highlighting the potential for selection for targeted nutritional gains. The seeds however, had less amounts of most of the quantified nutrients that also differed among the varieties. Significant intraspecific variation of the leaf total phenolics was also observed. With regard to the quantified nutritional elements in the flakes, the ethno-varieties were separated in space along PC1 (p < 0.001), PC2 (p < 0.001) and PC3 (p < 0.01) indicating their distinctness.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05916-5.

Association of Grain Iron and Zinc Content With Other Nutrients in Pearl Millet Germplasm, Breeding Lines, and Hybrids

Micronutrient deficiency is most prevalent in developing regions of the world, including Africa and Southeast Asia where pearl millet (Pennisetum glaucum L.) is a major crop. Increasing essential minerals in pearl millet through biofortification could reduce malnutrition caused by deficiency. This study evaluated the extent of variability of micronutrients (Fe, Zn, Mn, and Na) and macronutrients (P, K, Ca, and Mg) and their relationship with Fe and Zn content in 14 trials involving pearl millet hybrids, inbreds, and germplasm. Significant genetic variability of macronutrients and micronutrients was found within and across the trials (Ca: 4.2–40.0 mg 100 g⁻¹, Fe: 24–145 mg kg⁻¹, Zn: 22–96 mg kg⁻¹, and Na: 3.0–63 mg kg⁻¹). Parental lines showed significantly larger variation for nutrients than hybrids, indicating their potential for use in hybrid parent improvement through recurrent selection. Fe and Zn contents were positively correlated and highly significant (r = 0.58–0.81; p < 0.01). Fe and Zn were positively and significantly correlated with Ca (r = 0.26–0.61; p < 0.05) and Mn (r = 0.24–0.50; p < 0.05). The findings indicate that joint selection for Fe, Zn, and Ca will be effective. Substantial genetic variation and high heritability (>0.60) for multiple grain minerals provide good selection accuracy prospects for genetic enhancement. A highly positive significant correlation between Fe and Zn and the nonsignificant correlation of grain macronutrients and micronutrients with Fe and Zn suggest that there is scope to achieve higher levels of Fe/Zn simultaneously in current pearl millet biofortification efforts without affecting other grain nutrients. Results suggest major prospects for improving multiple nutrients in pearl millet.

Total Meat Intake is Associated with Life Expectancy: A Cross-Sectional Data Analysis of 175 Contemporary Populations

Background

The association between a plant-based diet (vegetarianism) and extended life span is increasingly criticised since it may be based on the lack of representative data and insufficient removal of confounders such as lifestyles.

Aim

We examined the association between meat intake and life expectancy at a population level based on ecological data published by the United Nations agencies.

Methods

Population-specific data were obtained from 175 countries/territories. Scatter plots, bivariate, partial correlation and linear regression models were used with SPSS 25 to explore and compare the correlations between newborn life expectancy (e₍₀₎), life expectancy at 5 years of life (e₍₅₎) and intakes of meat, and carbohydrate crops, respectively. The established risk factors to life expectancy – caloric intake, urbanization, obesity and education levels – were included as the potential confounders.

Results

Worldwide, bivariate correlation analyses revealed that meat intake is positively correlated with life expectancies. This relationship remained significant when influences of caloric intake, urbanization, obesity, education and carbohydrate crops were statistically controlled. Stepwise linear regression selected meat intake, not carbohydrate crops, as one of the significant predictors of life expectancy. In contrast, carbohydrate crops showed weak and negative correlation with life expectancy.

Conclusion

If meat intake is not incorporated into nutrition science for predicting human life expectancy, results could prove inaccurate.

Development of Selection Indices for Improvement of Seed Yield and Lipid Composition in Bambara Groundnut (Vigna subterranea (L.) Verdc.)

The underutilised grain legume bambara groundnut (Vigna subterranea) has the potential to contribute significantly to nutritional security. However, the lack of commercial cultivars has hindered its wider adoption and utilisation as a food source. The development of competitive cultivars is impeded by (1) lack of systematic data describing variation in nutritional composition within the gene pool, and (2) a poor understanding of how concentrations of different nutritional components interact. In this study, we analysed seed lipid and protein concentration and lipid composition within a collection of 100 lines representing the global gene pool. Seed protein and lipid varied over twofold with a normal distribution, but no significant statistical correlation was detected between the two components. Seed lipid concentration (4.2–8.8 g/100 g) is primarily determined by the proportion of oleic acid (r² = 0.45). Yield and composition data for a subset of 40 lines were then used to test selection parameters for high yielding, high lipid breeding lines. From five selection indices tested using 15 scenarios, an index based on the seed number, seed weight, and oleic acid yielded a >50% expected increase in each of the mean values of seed number, pod dry weight, seed dry weight, and seed size, as well as an expected 7% increase in seed lipid concentration.

Features and genetic basis of chlorogenic acid formation in diploid potatoes

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A diversity panel of lines was used to study the CGA formation in diploid potatoes.

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Decreased tuber CGA level was observed in the domesticated diploid potatoes.

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Potential factors affecting the CGA level in diploid potatoes were revealed.

The concentration of chlorogenic acids (CGAs), is tightly associated with the appearance, taste, and nutrient content of potato tubers. Manipulation of tuber CGA concentrations allows for the breeding of quality traits in potatoes. Currently, a hybrid potato breeding system that aims to convert tetraploid potato into a diploid seed crop represents a new development in potato breeding. Unfortunately, however, a systematic study of CGA formation is very limited in diploid potatoes. Here, using a diverse panel of diploid potatoes, including 40 ancestors and 374 landraces, we analyzed the influence of location, environment, genetic basis, as well as expression of enzymes, in affecting the CGA concentrations in diploid lines. We revealed a selection of the decreased CGA level of tuber flesh in the domestication of diploid potatoes. Moreover, we identified 18 SNPs associated with tuber CGA levels using re-sequenced genome data. This study provides a basis for the breeding of high-quality potato by taking into consideration customer preferences.

Metabolomics and Transcriptomics Provide Insights into Anthocyanin Biosynthesis in the Developing Grains of Purple Wheat (Triticum aestivum L.)

Purple wheat is thought to have beneficial effects on humans owing to its high anthocyanin content. However, a systematic understanding of the anthocyanin biosynthesis process in developing wheat grain is lacking. Here, the dynamic changes in anthocyanin components and transcripts in the grain of purple wheat ZNM168 at five developmental stages (10, 15, 20, 25, and 30 DAF) were characterized. Compared with other anthocyanins, four components, cyanidin 3-O-rutinoside, cyanidin 3-O-glucoside, cyanidin 3,5-O-diglucoside, and malvidin 3-O-glucoside, were significantly accumulated with grain development. In particular, the considerable accumulation of cyanidin 3-O-rutinoside indicated that it was the pivotal pigment for the purple grain. Transcriptome analysis revealed that the nine differentially expressed genes related to anthocyanin biosynthesis belonged to the BZ1 group, the homologous enzyme encoded by the maize Bronze-1 locus, which may primarily serve to glucosylate anthocyanidins. By constructing a gene coexpression network based on weighted gene coexpression network analysis, the TaBZ1 UniGene (TraesCS1D02G019200) was predicted as a core gene in anthocyanin biosynthesis. In addition, correlation analysis between the metabolites and transcripts suggested that TraesCS2A01G527700 (TaCHS) and TraesCS6B01G006200 (TaANS) were considered critical structural genes in the anthocyanin biosynthesis pathway. This study provides insights to exploit genes pinpointed as genetic engineering targets, thereby breeding anthocyanin-enriched wheat.

QTL Mapping for Grain Zinc and Iron Concentrations in Bread Wheat

Deficiency of micronutrient elements, such as zinc (Zn) and iron (Fe), is called “hidden hunger,” and bio-fortification is the most effective way to overcome the problem. In this study, a high-density Affymetrix 50K single-nucleotide polymorphism (SNP) array was used to map quantitative trait loci (QTL) for grain Zn (GZn) and grain Fe (GFe) concentrations in 254 recombinant inbred lines (RILs) from a cross Jingdong 8/Bainong AK58 in nine environments. There was a wide range of variation in GZn and GFe concentrations among the RILs, with the largest effect contributed by the line × environment interaction, followed by line and environmental effects. The broad sense heritabilities of GZn and GFe were 0.36 ± 0.03 and 0.39 ± 0.03, respectively. Seven QTL for GZn on chromosomes 1DS, 2AS, 3BS, 4DS, 6AS, 6DL, and 7BL accounted for 2.2–25.1% of the phenotypic variances, and four QTL for GFe on chromosomes 3BL, 4DS, 6AS, and 7BL explained 2.3–30.4% of the phenotypic variances. QTL on chromosomes 4DS, 6AS, and 7BL might have pleiotropic effects on both GZn and GFe that were validated on a germplasm panel. Closely linked SNP markers were converted to high-throughput KASP markers, providing valuable tools for selection of improved Zn and Fe bio-fortification in breeding.

Molecular Biology in the Improvement of Biological Nitrogen Fixation by Rhizobia and Extending the Scope to Cereals

The contribution of biological nitrogen fixation to the total N requirement of food and feed crops diminished in importance with the advent of synthetic N fertilizers, which fueled the “green revolution”. Despite being environmentally unfriendly, the synthetic versions gained prominence primarily due to their low cost, and the fact that most important staple crops never evolved symbiotic associations with bacteria. In the recent past, advances in our knowledge of symbiosis and nitrogen fixation and the development and application of recombinant DNA technology have created opportunities that could help increase the share of symbiotically-driven nitrogen in global consumption. With the availability of molecular biology tools, rapid improvements in symbiotic characteristics of rhizobial strains became possible. Further, the technology allowed probing the possibility of establishing a symbiotic dialogue between rhizobia and cereals. Because the evolutionary process did not forge a symbiotic relationship with the latter, the potential of molecular manipulations has been tested to incorporate a functional mechanism of nitrogen reduction independent of microbes. In this review, we discuss various strategies applied to improve rhizobial strains for higher nitrogen fixation efficiency, more competitiveness and enhanced fitness under unfavorable environments. The challenges and progress made towards nitrogen self-sufficiency of cereals are also reviewed. An approach to integrate the genetically modified elite rhizobia strains in crop production systems is highlighted.

Important determinants to take into account to optimize protein nutrition in the elderly: solutions to a complex equation

During ageing, skeletal muscle develops anabolic resistance towards the stimulation of protein synthesis induced by dietary amino acids. The stimulation of muscle protein synthesis after food intake remains insufficient, even with a protein intake recommended for healthy adults. This alteration is one of the mechanisms known to be responsible for the decrease of muscle mass and function during ageing, namely sarcopenia. Increasing dietary protein intake above the current RDA(0⋅83 g/kg/d) has been strongly suggested to overcome the anabolic resistance observed. It is also specified that the dietary protein ingested should be of good quality. A protein of good quality is a protein whose amino acid (AA) composition covers the requirement of each AA when ingested at the RDA. However, the biological value of proteins may vary among dietary sources in which AA composition could be unbalanced. In the present review, we suggest that the quality of a dietary protein is also related to several other determinants. These determinants include the speed of digestion of dietary proteins, the presence of specific AA, the food matrix in which the dietary proteins are included, the processes involved in the production of food products (milk gelation and cooking temperature), the energy supply and its nature, and the interaction between nutrients before ingestion. Particular attention is given to plant proteins for nutrition of the elderly. Finally, the timing of protein intake and its association with the desynchronized intake of energetic nutrients are discussed.

Historical changes in the contents and compositions of fibre components and polar metabolites in white wheat flour

Thirty-nine UK adapted wheat cultivars dating from between 1790 and 2012 were grown in replicated randomised field trials for three years, milled, and white flour analysed for the contents of dietary fibre components (arabinoxylan and β-glucan) and polar metabolites (sugars, amino acids, organic acids, choline and betaine) to determine whether the composition had changed due to the effects of intensive breeding. The concentrations of components varied between study years, indicating strong effects of environment. Nevertheless, some trends were observed, with the concentrations of arabinoxylan fibre and soluble sugars (notably sucrose, maltose and fructose) increasing and most amino acids (including asparagine which is the precursor of acrylamide formed during processing) decreasing between the older and newer types. The concentration of betaine, which is beneficial for cardio-vascular health, also increased. The study therefore provided no evidence for adverse effects of intensive breeding on the contents of beneficial components in wheat flour.

Large-scale GWAS in sorghum reveals common genetic control of grain size among cereals

Grain size is a key yield component of cereal crops and a major quality attribute. It is determined by a genotype's genetic potential and its capacity to fill the grains. This study aims to dissect the genetic architecture of grain size in sorghum. An integrated genome-wide association study (GWAS) was conducted using a diversity panel (n = 837) and a BC-NAM population (n = 1421). To isolate genetic effects associated with genetic potential of grain size, rather than the genotype's capacity to fill the grains, a treatment of removing half of the panicle was imposed during flowering. Extensive and highly heritable variation in grain size was observed in both populations in 5 field trials, and 81 grain size QTL were identified in subsequent GWAS. These QTL were enriched for orthologues of known grain size genes in rice and maize, and had significant overlap with SNPs associated with grain size in rice and maize, supporting common genetic control of this trait among cereals. Grain size genes with opposite effect on grain number were less likely to overlap with the grain size QTL from this study, indicating the treatment facilitated identification of genetic regions related to the genetic potential of grain size. These results enhance understanding of the genetic architecture of grain size in cereal, and pave the way for exploration of underlying molecular mechanisms and manipulation of this trait in breeding practices.

Bridging the food security gap: an information-led approach to connect dietary nutrition, food composition and crop production

BACKGROUND

Food security is recognized as a major global challenge, yet human food-chain systems are inherently not geared towards nutrition, with decisions on crop and cultivar choice not informed by dietary composition. Currently, food compositional tables and databases (FCT/FCDB) are the primary information sources for decisions relating to dietary intake. However, these only present single mean values representing major components. Establishment of a systematic controlled vocabulary to fill this gap requires representation of a more complex set of semantic relationships between terms used to describe nutritional composition and dietary function.

RESULTS

We carried out a survey of 11 FCT/FCDB and 177 peer-reviewed papers describing variation in nutritional composition and dietary function for food crops to identify a comprehensive set of terms to construct a controlled vocabulary. We used this information to generate a Crop Dietary Nutrition Data Framework (CDN-DF), which incorporates controlled vocabularies systematically organized into major classes representing nutritional components and dietary functions. We demonstrate the value of the CDN-DF for comparison of equivalent components between crop species or cultivars, for identifying data gaps and potential for formal meta-analysis. The CDN-DF also enabled us to explore relationships between nutritional components and the functional attributes of food.

CONCLUSION

We have generated a structured crop dietary nutrition data framework, which is generally applicable to the collation and comparison of data relevant to crop researchers, breeders, and other stakeholders, and will facilitate dialogue with nutritionists. It is currently guiding the establishment of a more robust formal ontology. © 2019 Society of Chemical Industry.

Color Mutations Alter the Biochemical Composition in the San Marzano Tomato Fruit

San Marzano (SM) is a traditional Italian landrace characterized by red elongated fruits, originating in the province of Naples (Italy) and cultivated worldwide. Three mutations, yellow flesh (r), green flesh (gf) and colorless fruit epidermis (y) were introduced into SM by backcross and the resulting introgression lines (ILs) produced the expected yellow, brown and pink fruit variants. In addition, ILs carrying double combinations of those mutations were obtained. The six ILs plus the SM reference were analyzed for volatile (VOC), non-polar (NP) and polar (P) metabolites. Sixty-eight VOCs were identified, and several differences evidenced in the ILs; overall gf showed epistasis over r and y and r over y. Analysis of the NP component identified 54 metabolites; variation in early carotenoids (up to lycopene) and chlorophylls characterized respectively the ILs containing r and gf. In addition, compounds belonging to the quinone and xanthophyll classes were present in genotypes carrying the r mutation at levels higher than SM. Finally, the analysis of 129 P metabolites evidenced different levels of vitamins, amino acids, lipids and phenylpropanoids in the ILs. A correlation network approach was used to investigate metabolite-metabolite relationships in the mutant lines. Altogether these differences potentially modified the hedonistic and nutritional value of the berry. In summary, single and combined mutations in gf, r and y generated interesting visual and compositional diversity in the SM landrace, while maintaining its original typology.

Hedonic evaluation and check-all-that-apply (CATA) question for sensory characterisation of stewed vegetable Amaranthus

Hedonic assessment and sensory characteristics of 13 Amaranthus genotypes, stewed with onions, tomatoes and potatoes, were evaluated. 50 consumers ranked their preference on a nine-point hedonic scale to determine overall acceptability of the stewed samples. In addition, 100 consumers were asked to select sensory characteristics that described the genotypes best, using the Check-all-that-apply question. Hedonic responses indicated significant differences (p < 0.001) between stewed samples. Significant differences were also found in the frequency with which consumers used 15 of the 23 terms generated to characterise the sensory profile of stewed Amaranthus leaves. Correspondence analysis illustrated differences in sensory characteristics between genotypes, describing 72.4% variance. Agglomerative hierarchical clustering indicated three consumer preference clusters, while external preference mapping showed the regions of maximum liking. There was no correlation between hedonic evaluation and sensory characteristics. In addition, no strong association between specific species, genotypes and sensory attributes was observed.

Mineral Element Composition in Grain of Awned and Awnletted Wheat (Triticum aestivum L.) Cultivars: Tissue-Specific Iron Speciation and Phytate and Non-Phytate Ligand Ratio

In wheat (Triticum aestivum L.), the awns—the bristle-like structures extending from lemmas—are photosynthetically active. Compared to awned cultivars, awnletted cultivars produce more grains per unit area and per spike, resulting in significant reduction in grain size, but their mineral element composition remains unstudied. Nine awned and 11 awnletted cultivars were grown simultaneously in the field. With no difference in 1000-grain weight, a larger calcium and manganese—but smaller iron (Fe) concentrations—were found in whole grain of awned than in awnletted cultivars. Micro X-ray absorption near edge structure analysis of different tissues of frozen-hydrated grain cross-sections revealed that differences in total Fe concentration were not accompanied by differences in Fe speciation (64% of Fe existed as ferric and 36% as ferrous species) or Fe ligands (53% were phytate and 47% were non-phytate ligands). In contrast, there was a distinct tissue-specificity with pericarp containing the largest proportion (86%) of ferric species and nucellar projection (49%) the smallest. Phytate ligand was predominant in aleurone, scutellum and embryo (72%, 70%, and 56%, respectively), while nucellar projection and pericarp contained only non-phytate ligands. Assuming Fe bioavailability depends on Fe ligands, we conclude that Fe bioavailability from wheat grain is tissue specific.

Natural Variation in Ovule Morphology Is Influenced by Multiple Tissues and Impacts Downstream Grain Development in Barley (Hordeum vulgare L.)

The ovule plays a critical role in cereal yield as it is the site of fertilization and the progenitor of the grain. The ovule primordium is generally comprised of three domains, the funiculus, chalaza, and nucellus, which give rise to distinct tissues including the integuments, nucellar projection, and embryo sac. The size and arrangement of these domains varies significantly between model eudicots, such as Arabidopsis thaliana, and agriculturally important monocotyledonous cereal species, such as Hordeum vulgare (barley). However, the amount of variation in ovule development among genotypes of a single species, and its functional significance, remains unclear. To address this, wholemount clearing was used to examine the details of ovule development in barley. Nine sporophytic and gametophytic features were examined at ovule maturity in a panel of 150 European two-row spring barley genotypes, and compared with grain traits from the preceding and same generation. Correlations were identified between ovule traits and features of grain they produced, which in general highlighted a negative correlation between nucellus area, ovule area, and grain weight. We speculate that the amount of ovule tissue, particularly the size of the nucellus, may affect the timing of maternal resource allocation to the fertilized embryo sac, thereby influencing subsequent grain development.

State of the art in eukaryotic nitrogenase engineering

Improving the ability of plants and plant-associated organisms to fix and assimilate atmospheric nitrogen has inspired plant biotechnologists for decades, not only to alleviate negative effects on nature from increased use and availability of reactive nitrogen, but also because of apparent economic benefits and opportunities. The combination of recent advances in synthetic biology and increased knowledge about the biochemistry and biosynthesis of the nitrogenase enzyme has made the seemingly remote and for long unreachable dream more possible. In this review, we will discuss strategies how this could be accomplished using biotechnology, with a special focus on recent progress on engineering plants to express its own nitrogenase.

Novel Grain Weight Loci Revealed in a Cross between Cultivated and Wild Sorghum

Grain weight has increased during domestication of cereals. Together with grain number it determines yield, but the two are often negatively correlated. Understanding the genetic architecture of grain weight and its relationship with grain number is critical to enhance crop yield. Sorghum is an important food, feed, and biofuel crop well-known for its adaptation to drought and heat. This study aimed to dissect the genetic basis of thousand grain weight (TGW) in a BCF population between a domesticated sorghum accession and its wild progenitor, subsp. and investigate its relationship with grain number. Thousand grain weight, grain number, and yield were measured in field trials in two successive years. A strong negative correlation between TGW and grain number was observed in both trials. In total, 17 TGW quantitative trait loci (QTL) were identified, with 11 of them exhibiting an opposing effect on grain number, implying the correlation between TGW and grain number is due to pleiotropy. Nine grain size candidate genes were identified within 6 TGW QTL, and of these 5 showed signatures of selection during sorghum domestication. Large-effect QTL in this study that have not been identified previously in cultivated sorghum were found to contain candidate genes with domestication signal, indicating that these QTL were affected during sorghum domestication. This study sheds new light on the genetic basis of TGW, its relationship with grain number, and sorghum domestication.

Occurrence of serum antibodies against wheat alpha-amylase inhibitor 0.19 in celiac disease

The alcohol-soluble fraction of wheat gluten (gliadins) induces in genetically susceptible individuals immunologically mediated celiac disease (CLD). However, gliadins and related cereal proteins are not unique foodstuff targets of CLD patients´ immune system. Non-gluten wheat alpha-amylase inhibitor 0.19 (AAI 0.19) has been found to be capable of activating human monocyte-derived dendritic cells and inducing pro-inflammatory status in intestinal mucosa of patients with celiac disease (CLD). The possible contribution of this reactivity in incomplete remission of CLD patients on a gluten-free diet (GFD) is matter of contention. In an attempt to characterize the antigenicity of AAI 0.19 in patients with active CLD, patients on a GFD and healthy controls we developed ELISA employing wheat recombinant AAI 0.19. Using this test we revealed a significant (P<0.001) elevation of IgA anti-AAI 0.19 antibodies (Ab) in patients with active CLD (12 out of 30 patients were seropositive) but also in CLD patients on a GFD (15/46), in contrast to healthy controls (2/59). Anti-AAI 0.19 IgG Ab levels were increased (P<0.001) only in patients with active CLD (14/30) in contrast to the controls. Interestingly, the levels of anti-AAI 0.19 IgG Ab were decreased in CLD patients on a GFD (P<0.001, 1/46) compared to the controls (1/59). Notably, 20 out of 30 patients with active CLD were positive either for IgA or for IgG anti-AAI 0.19 Ab. Thus, the majority of CLD patients developed a robust IgA and IgG Ab response against AAI 0.19. These findings may contribute to the broadening of the knowledge about CLD pathogenesis.

Protein for Life: Review of Optimal Protein Intake, Sustainable Dietary Sources and the Effect on Appetite in Ageing Adults

With an ageing population, dietary approaches to promote health and independence later in life are needed. In part, this can be achieved by maintaining muscle mass and strength as people age. New evidence suggests that current dietary recommendations for protein intake may be insufficient to achieve this goal and that individuals might benefit by increasing their intake and frequency of consumption of high-quality protein. However, the environmental effects of increasing animal-protein production are a concern, and alternative, more sustainable protein sources should be considered. Protein is known to be more satiating than other macronutrients, and it is unclear whether diets high in plant proteins affect the appetite of older adults as they should be recommended for individuals at risk of malnutrition. The review considers the protein needs of an ageing population (>40 years old), sustainable protein sources, appetite-related implications of diets high in plant proteins, and related areas for future research.

Identifying Candidate Genes for Enhancing Grain Zn Concentration in Wheat

Wheat (Triticum aestivum L.) is one of the major staple food crops worldwide. Despite efforts in improving wheat quality, micronutrient levels are still below the optimal range for human nutrition. In particular, zinc (Zn) deficiency is a widespread problem in human nutrition in countries relying mainly on a cereal diet; hence improving Zn accumulation in grains is an imperative need. This study was designed to understand the genetic architecture of Zn grain concentrations in wheat grains. We performed a genome-wide association study (GWAS) for grain Zn concentrations in 369 European wheat genotypes, using field data from 3 years. The complete wheat panel was genotyped by high-density arrays of single nucleotide polymorphic (SNP) markers (90k iSELECT Infinium and 35k Affymetrix arrays) resulting in 15,523 polymorphic markers. Additionally, a subpanel of 183 genotypes was analyzed with a novel 135k Affymetrix marker array resulting in 28,710 polymorphic SNPs for high-resolution mapping of the potential genomic regions. The mean grain Zn concentration of the genotypes ranged from 25.05-52.67 μg g^-1 dry weight across years with a moderate heritability value. Notably, 40 marker-trait associations (MTAs) were detected in the complete panel of varieties on chromosomes 2A, 3A, 3B, 4A, 4D, 5A, 5B, 5D, 6D, 7A, 7B, and 7D. The number of MTAs in the subpanel was increased to 161 MTAs whereas the most significant and consistent associations were located on chromosomes 3B (723,504,241-723,611,488 bp) and 5A (462,763,758-466,582,184 bp) having major effects. These genomic regions include newly identified putative candidate genes, which are related to Zn uptake and transport or represent bZIP and mitogen-activated protein kinase genes. These findings provide the basis for understanding the genetic background of Zn concentration in wheat grains that in turn may help breeders to select high Zn-containing genotypes to improve human health and grain quality.

Identifying Candidate Genes for Enhancing Grain Zn Concentration in Wheat

Wheat (Triticum aestivum L.) is one of the major staple food crops worldwide. Despite efforts in improving wheat quality, micronutrient levels are still below the optimal range for human nutrition. In particular, zinc (Zn) deficiency is a widespread problem in human nutrition in countries relying mainly on a cereal diet; hence improving Zn accumulation in grains is an imperative need. This study was designed to understand the genetic architecture of Zn grain concentrations in wheat grains. We performed a genome-wide association study (GWAS) for grain Zn concentrations in 369 European wheat genotypes, using field data from 3 years. The complete wheat panel was genotyped by high-density arrays of single nucleotide polymorphic (SNP) markers (90k iSELECT Infinium and 35k Affymetrix arrays) resulting in 15,523 polymorphic markers. Additionally, a subpanel of 183 genotypes was analyzed with a novel 135k Affymetrix marker array resulting in 28,710 polymorphic SNPs for high-resolution mapping of the potential genomic regions. The mean grain Zn concentration of the genotypes ranged from 25.05-52.67 μg g^-1 dry weight across years with a moderate heritability value. Notably, 40 marker-trait associations (MTAs) were detected in the complete panel of varieties on chromosomes 2A, 3A, 3B, 4A, 4D, 5A, 5B, 5D, 6D, 7A, 7B, and 7D. The number of MTAs in the subpanel was increased to 161 MTAs whereas the most significant and consistent associations were located on chromosomes 3B (723,504,241-723,611,488 bp) and 5A (462,763,758-466,582,184 bp) having major effects. These genomic regions include newly identified putative candidate genes, which are related to Zn uptake and transport or represent bZIP and mitogen-activated protein kinase genes. These findings provide the basis for understanding the genetic background of Zn concentration in wheat grains that in turn may help breeders to select high Zn-containing genotypes to improve human health and grain quality.

Evaluation of the Effect of Planting Distance and Harvesting Time on the Carotenoids and Phytochemicals of Selected Orange-Fleshed Sweet Potato Varieties

We evaluated the carotenoid profile and concentration (by HPLC) and the phytochemical content of two OFSP varieties (Umuspo 3 and Ex-Igbariam) planted at three distances (20 cm, 30 cm and 40 cm) and harvested in two different periods (12th and 16th weeks after planting) respectively. Carotene contents of the outer peel and inner flesh of the sweet potato varieties were also determined. The results showed wide variation in the carotenoid and phytochemical content among the varieties at different planting spaces and harvest periods. Umuspo 3 planted at 20 cm, 30 cm and 40 cm had significantly greater carotenoid concentration than Ex-Igbariam variety. The predominant carotenoid was β-carotene with highest concentration obtained from 40 cm planting distance (92.82µg/g) and 30 cm (80.97µg/g) for Umuspo 3. Ex-Igbariam at 30 cm planting distance contained 2.51µg/g β-carotene when harvested after 16th weeks. Also the highest β-carotene concentration was from Umuspo 3 flesh sample planted 30 and 40 cm (409.45 and 441.15 mg/100g) and the peel for samples planted 30 and 40 cm (490.47 and 640.69 mg/100g, respectively) at the 12th week of harvest. Flavonoids were present in significant amounts (310.62mg/100g) in Umuspo 3 planted at 30 cm and harvested after 12th week while in total polyphenol, significant quantities of ≈42.12mg/100g was present in Ex-Igbariam spaced at 30 cm and 40 cm and harvested after 16th week. Provitamin A carotenoid was calculated and Umuspo 3 pro-vitamin A carotenoid was significantly higher (p< 0.05) with highest concentration (742.26 RE/100g) present in samples from 40 cm planting distance. The results showed that planting space and harvesting period had significant impact on the carotenoid and phytochemical concentrations of OFSP varieties. Planting distances of 30 and 40 cm are recommended for high carotenoid content in the two sweet potato varieties.

Evaluation of the Effect of Planting Distance and Harvesting Time on the Carotenoids and Phytochemicals of Selected Orange-Fleshed Sweet Potato Varieties

We evaluated the carotenoid profile and concentration (by HPLC) and the phytochemical content of two OFSP varieties (Umuspo 3 and Ex-Igbariam) planted at three distances (20 cm, 30 cm and 40 cm) and harvested in two different periods (12thand 16thweeks after planting) respectively. Carotene contents of the outer peel and inner flesh of the sweet potato varieties were also determined. The results showed wide variation in the carotenoid and phytochemical content among the varieties at different planting spaces and harvest periods. Umuspo 3 planted at 20 cm, 30 cm and 40 cm had significantly greater carotenoid concentration than Ex-Igbariam variety. The predominant carotenoid was β-carotene with highest concentration obtained from 40 cm planting distance (92.82µg/g) and 30 cm (80.97µg/g) for Umuspo 3. Ex-Igbariam at 30 cm planting distance contained 2.51µg/g β-carotene when harvested after 16thweeks. Also the highest β-carotene concentration was from Umuspo 3 flesh sample planted 30 and 40 cm (409.45 and 441.15 mg/100g) and the peel for samples planted 30 and 40 cm (490.47 and 640.69 mg/100g, respectively) at the 12thweek of harvest. Flavonoids were present in significant amounts (310.62mg/100g) in Umuspo 3 planted at 30 cm and harvested after 12thweek while in total polyphenol, significant quantities of ≈42.12mg/100g was present in Ex-Igbariam spaced at 30 cm and 40 cm and harvested after 16thweek. Provitamin A carotenoid was calculated and Umuspo 3 pro-vitamin A carotenoid was significantly higher (p< 0.05) with highest concentration (742.26 RE/100g) present in samples from 40 cm planting distance. The results showed that planting space and harvesting period had significant impact on the carotenoid and phytochemical concentrations of OFSP varieties. Planting distances of 30 and 40 cm are recommended for high carotenoid content in the two sweet potato varieties.

Identification of major loci and genomic regions controlling acid and volatile content in tomato fruit: implications for flavor improvement

Plant metabolites are important to world food security due to their roles in crop yield and nutritional quality. Here we report the metabolic profile of 300 tomato accessions (Solanum lycopersicum and related wild species) by quantifying 60 primary and secondary metabolites, including volatile organic compounds, over a period of 2 yr. Metabolite content and genetic inheritance of metabolites varied broadly, both within and between different genetic groups. Using genotype information gained from 10 000 single nucleotide polymorphism markers, we performed a metabolite genome-wide association mapping (GWAS) study. We identified 79 associations influencing 13 primary and 19 secondary metabolites with large effects at high resolution. Four genome regions were detected, highlighting clusters of associations controlling the variation of several metabolites. Local linkage disequilibrium analysis and allele mining identified possible candidate genes which may modulate the content of metabolites that are of significant importance for human diet and fruit consumption. We precisely characterized two associations involved in fruit acidity and phenylpropanoid volatile production. Taken together, this study reveals complex and distinct metabolite regulation in tomato subspecies and demonstrates that GWAS is a powerful tool for gene-metabolite annotation and identification, pathways elucidation, and further crop improvement.

Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops

Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.

Whole-Genome Analysis of Candidate genes Associated with Seed Size and Weight in Sorghum bicolor Reveals Signatures of Artificial Selection and Insights into Parallel Domestication in Cereal Crops

Seed size and seed weight are major quality attributes and important determinants of yield that have been strongly selected for during crop domestication. Limited information is available about the genetic control and genes associated with seed size and weight in sorghum. This study identified sorghum orthologs of genes with proven effects on seed size and weight in other plant species and searched for evidence of selection during domestication by utilizing resequencing data from a diversity panel. In total, 114 seed size candidate genes were identified in sorghum, 63 of which exhibited signals of purifying selection during domestication. A significant number of these genes also had domestication signatures in maize and rice, consistent with the parallel domestication of seed size in cereals. Seed size candidate genes that exhibited differentially high expression levels in seed were also found more likely to be under selection during domestication, supporting the hypothesis that modification to seed size during domestication preferentially targeted genes for intrinsic seed size rather than genes associated with physiological factors involved in the carbohydrate supply and transport. Our results provide improved understanding of the complex genetic control of seed size and weight and the impact of domestication on these genes.

Arbuscular mycorrhiza improves yield and nutritional properties of onion (Allium cepa)

Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogues and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity.

Association of Increased Grain Iron and Zinc Concentrations with Agro-morphological Traits of Biofortified Rice

Biofortification of rice (Oryza sativa L.) with micronutrients is widely recognized as a sustainable strategy to alleviate human iron (Fe) and zinc (Zn) deficiencies in developing countries where rice is the staple food. Constitutive overexpression of the rice nicotianamine synthase (OsNAS) genes has been successfully implemented to increase Fe and Zn concentrations in unpolished and polished rice grain. Intensive research is now needed to couple this high-micronutrient trait with high grain yields. We investigated associations of increased grain Fe and Zn concentrations with agro-morphological traits of backcross twice second filial (BC₂F₂) transgenic progeny carrying OsNAS1 or OsNAS2 overexpression constructs under indica/japonica and japonica/japonica genetic backgrounds. Thirteen agro-morphological traits were evaluated in BC₂F₂ transgenic progeny grown under hydroponic conditions. Concentrations of eight mineral nutrients (Fe, Zn, copper, manganese, calcium, magnesium, potassium, and phosphorus) in roots, stems/sheaths, non-flag leaves, flag leaves, panicles, and grain were also determined. A distance-based linear model (DistLM) was utilized to extract plant tissue nutrient predictors accounting for the largest variation in agro-morphological traits differing between transgenic and non-transgenic progeny. Overall, the BC₂F₂ transgenic progeny contained up to 148% higher Fe and 336% higher Zn concentrations in unpolished grain compared to non-transgenic progeny. However, unpolished grain concentrations surpassing 23 μg Fe g^-1 and 40 μg Zn g^-1 in BC₂F₂indica/japonica progeny, and 36 μg Fe g^-1 and 56 μg Zn g¹ in BC₂F₂japonica/japonica progeny, were associated with significant reductions in grain yield. DistLM analyses identified grain-Zn and panicle-magnesium as the primary nutrient predictors associated with grain yield reductions in the indica/japonica and japonica/japonica background, respectively. We subsequently produced polished grain from high-yield BC₂F₂ transgenic progeny carrying either the OsNAS1 or OsNAS2 overexpression constructs. The OsNAS2 overexpressing progeny had higher percentages of Fe and Zn in polished rice grain compared to the OsNAS1 overexpressing progeny. Results from this study demonstrate that genetic background has a major effect on the development of Fe and Zn biofortified rice. Moreover, our study shows that high-yielding rice lines with Fe and Zn biofortified polished grain can be developed by OsNAS2 overexpression and monitoring for Zn overaccumulation in the grain.

Breeding Vegetables with Increased Content in Bioactive Phenolic Acids

Vegetables represent a major source of phenolic acids, powerful antioxidants characterized by an organic carboxylic acid function and which present multiple properties beneficial for human health. In consequence, developing new varieties with enhanced content in phenolic acids is an increasingly important breeding objective. Major phenolic acids present in vegetables are derivatives of cinnamic acid and to a lesser extent of benzoic acid. A large diversity in phenolic acids content has been found among cultivars and wild relatives of many vegetable crops. Identification of sources of variation for phenolic acids content can be accomplished by screening germplasm collections, but also through morphological characteristics and origin, as well as by evaluating mutations in key genes. Gene action estimates together with relatively high values for heritability indicate that selection for enhanced phenolic acids content will be efficient. Modern genomics and biotechnological strategies, such as QTL detection, candidate genes approaches and genetic transformation, are powerful tools for identification of genomic regions and genes with a key role in accumulation of phenolic acids in vegetables. However, genetically increasing the content in phenolic acids may also affect other traits important for the success of a variety. We anticipate that the combination of conventional and modern strategies will facilitate the development of a new generation of vegetable varieties with enhanced content in phenolic acids.

Enabling nutrient security and sustainability through systems research

Human and companion animal health depends upon nutritional quality of foods. Seed varieties, seasonal and local growing conditions, transportation, food processing, and storage, and local food customs can influence the nutrient content of food. A new and intensive area of investigation is emerging that recognizes many factors in these agri-food systems that influence the maintenance of nutrient quality which is fundamental to ensure nutrient security for world populations. Modeling how these systems function requires data from different sectors including agricultural, environmental, social, and economic, but also must incorporate basic nutrition and other biomedical sciences. Improving the agri-food system through advances in pre- and post-harvest processing methods, biofortification, or fortifying processed foods will aid in targeting nutrition for populations and individuals. The challenge to maintain and improve nutrient quality is magnified by the need to produce food locally and globally in a sustainable and consumer-acceptable manner for current and future populations. An unmet requirement for assessing how to improve nutrient quality, however, is the basic knowledge of how to define health. That is, health cannot be maintained or improved by altering nutrient quality without an adequate definition of what health means for individuals and populations. Defining and measuring health therefore becomes a critical objective for basic nutritional and other biomedical sciences.

Comparative transcriptional profiling of two wheat genotypes, with contrasting levels of minerals in grains, shows expression differences during grain filling

Wheat is one of the most important cereal crops in the world. To identify the candidate genes for mineral accumulation, it is important to examine differential transcriptome between wheat genotypes, with contrasting levels of minerals in grains. A transcriptional comparison of developing grains was carried out between two wheat genotypes- Triticum aestivum Cv. WL711 (low grain mineral), and T. aestivum L. IITR26 (high grain mineral), using Affymetrix GeneChip Wheat Genome Array. The study identified a total of 580 probe sets as differentially expressed (with log2 fold change of ≥2 at p≤0.01) between the two genotypes, during grain filling. Transcripts with significant differences in induction or repression between the two genotypes included genes related to metal homeostasis, metal tolerance, lignin and flavonoid biosynthesis, amino acid and protein transport, vacuolar-sorting receptor, aquaporins, and stress responses. Meta-analysis revealed spatial and temporal signatures of a majority of the differentially regulated transcripts.

Mechanisms of tolerance and high degradation capacity of the herbicide mesotrione by Escherichia coli strain DH5-α

The intensive use of agrochemicals has played an important role in increasing agricultural production. One of the impacts of agrochemical use has been changes in population structure of soil microbiota. The aim of this work was to analyze the adaptive strategies that bacteria use to overcome oxidative stress caused by mesotrione, which inhibits 4-hydroxyphenylpyruvate dioxygenase. We also examined antioxidative stress systems, saturation changes of lipid membranes, and the capacity of bacteria to degrade mesotrione. Escherichia coli DH5-á was chosen as a non-environmental strain, which is already a model bacterium for studying metabolism and adaptation. The results showed that this bacterium was able to tolerate high doses of the herbicide (10× field rate), and completely degraded mesotrione after 3 h of exposure, as determined by a High Performance Liquid Chromatography. Growth rates in the presence of mesotrione were lower than in the control, prior to the period of degradation, showing toxic effects of this herbicide on bacterial cells. Changes in the saturation of the membrane lipids reduced the damage caused by reactive oxygen species and possibly hindered the entry of xenobiotics in the cell, while activating glutathione-S-transferase enzyme in the antioxidant system and in the metabolizing process of the herbicide. Considering that E. coli DH5-α is a non-environmental strain and it had no previous contact with mesotrione, the defense system found in this strain could be considered non-specific. This bacterium system response may be a general adaptation mechanism by which bacterial strains resist to damage from the presence of herbicides in agricultural soils.

An update on magnesium homeostasis mechanisms in plants

Worldwide, nearly two-thirds of the population do not consume the recommended amount of magnesium (Mg) in their diet. Furthermore, low Mg status (hypomagnesaemia) is known to contribute to a number of human chronic disease conditions. Because the principal dietary Mg source is of plant origin, agronomic and genetic biofortification strategies are aimed at improving nutritional Mg content in food crops to overcome this mineral deficiency in humans. This update incorporates the contributions of annotated permeases involved in Mg uptake, storage and recycling with a schematic model of Mg movement at the organ and cellular levels in the model species Arabidopsis thaliana. Furthermore, approaches using mutagenesis or natural ionomic variation to identify loci involved in Mg homeostasis in roots, leaves and seeds will be summarised. A brief overview will be presented on how Arabidopsis research can help to develop strategies for biofortification of crops.

Regulation of Intestinal Immune Responses through TLR Activation: Implications for Pro- and Prebiotics

The intestinal mucosa is constantly facing a high load of antigens including bacterial antigens derived from the microbiota and food. Despite this, the immune cells present in the gastrointestinal tract do not initiate a pro-inflammatory immune response. Toll-like receptors (TLRs) are pattern recognition receptors expressed by various cells in the gastrointestinal tract, including intestinal epithelial cells (IEC) and resident immune cells in the lamina propria. Many diseases, including chronic intestinal inflammation (e.g., inflammatory bowel disease), irritable bowel syndrome (IBS), allergic gastroenteritis (e.g., eosinophilic gastroenteritis and allergic IBS), and infections are nowadays associated with a deregulated microbiota. The microbiota may directly interact with TLR. In addition, differences in intestinal TLR expression in health and disease may suggest that TLRs play an essential role in disease pathogenesis and may be novel targets for therapy. TLR signaling in the gut is involved in either maintaining intestinal homeostasis or the induction of an inflammatory response. This mini review provides an overview of the current knowledge regarding the contribution of intestinal epithelial TLR signaling in both tolerance induction or promoting intestinal inflammation, with a focus on food allergy. We will also highlight a potential role of the microbiota in regulating gut immune responses, especially through TLR activation.