Metabolomics and gene expression analysis reveal the accumulation patterns of phenylpropanoids and flavonoids in different colored-grain wheats (Triticum aestivum L.)

Metabolic and molecular basis of flavonoid biosynthesis in Lycii fructus: An integration of metabolomic and transcriptomic analysis

Flavonoids serve as bioactive components and contribute to medicinal and nutritional profile of Lycii fructus. However, there is limited information regarding the influence of ecological environments on the flavonoid biosynthesis pathway. In this study, we integrated transcriptome sequencing and metabonomic techniques across three distinct cultivation regions to elucidate the processes of flavonoids biosynthesis and the associated gene expression levels in L. fructus. LC-MS/MS based metabolomics revealed significant variations in metabolite profiles including 43 differential flavonoid metabolites, predominantly consisting of flavanol compounds across diverse regions. Additionally, 154 significantly differentially expressed genes (DEGs) were categorized in the flavonoid biosynthesis identified by de novo transcriptome assembly. Transcription factors C2C2 MYB, NAC, WRKY, AP2/ERF and B3 superfamily were the mainly hub genes regulating the flavonoids biosynthesis. The flavonoid pathway was built through integrated analysis of DEGs and DAMs to illustrate the molecular mechanism of flavonoid biosynthesis. Precipitation and temperature may serve as the primary environmental factors that affected the flavonoids variations. This study proposed a schematic of flavonoid biosynthesis in L. fructus, and further provided evidence for environmental response of L. fructus.

Cooperation mechanism of flavonoid transformation by Bifidobacterium animalis subsp. lactis and Lacticaseibacillus paracasei

Elaeagnus moorcroftii Wall. ex Schlecht (EWS) as a suitable food matrix contains abundant flavonoids for promoting human health, this study aimed to use flavonoid-targeted metabolomics and transcriptome sequencing to investigate the transformation of flavonoids in EWS juice (EWSJ) by mono- and mixed-cultures fermentations of Bifidobacterium animalis subsp. lactis HN-3 (B.an3) and Lacticaseibacillus paracasei YL-29 (L.cp29). A total of 33 flavonoids were identified in mono- and mixed-cultures fermented EWSJ. Among them, fermentation by B.an3 produced specific deglycosylation products (kaempferol (17.6 mmol/L) and luteolin (4.5 mmol/L)) and methoxylation products (syringaldehyde (59.05 mmol/L)), and fermentation by L.cp29 resulted in a specific deglycosylation product (quercetin (9.2 mmol/L)). The co-culture fermentation further increased the levels of isorhamnetin (52.3 mmol/L), and produced a specific product (homoplantaginin (0.03 mmol/L)), which significantly increased the bioactive-form flavonoids. Moreover, we analyzed changes in different flavonoid metabolites and differential genes before and after fermentation. After L.cp29 fermentation the expression of glycoside hydrolases and oxidoreductases were increased compared to other groups. After B.an3 fermentation the expression of isomerases and synthetases were increased compared to other groups. In particular, 6-phosphogluconolactonase (Pgl) and glucose-6-phosphate isomerase (Pgi) were increased in B.an3 fermentation. Thus, we validated the predicted transformation reactions by the biotransformation of flavonoids by the collected strains and crude enzyme extracts of B.an3 and L.cp29. These findings provided a basis for the development of functional plant-based foods with enhanced bioactive flavonoids.

Variations in the End-Use Quality of Whole Grain Flour Are Closely Related to the Metabolites in the Grains of Pigmented Wheat (Triticum aestivum L.)

Whole grain flour is considered a part of a healthy diet, especially when produced with pigmented wheat (Triticum aestivum). However, the specific metabolic pathways and mechanisms by which these metabolites affect the end-use quality of pigmented wheat varieties still need to be better understood. This study examined the relationship between metabolite concentrations and the end-use quality of three wheat varieties: common wheat (CW, JM20), black wheat (BW, HJ1), and green wheat (GW, HZ148). The study's findings revealed significant differences in the accumulation of metabolic substances among the various pigmented wheat varieties. Specifically, BW and GW exhibited notably higher levels of amino acids, derivatives, and lipids than CW. The study's findings revealed significant differences in the accumulation of metabolic substances among the various pigmented wheat varieties. Specifically, BW and GW exhibited notably higher levels of amino acids and their derivatives and lipids than CW. Amino acid derivatives, such as glutathione and creatine, are compounds formed through chemical modifications of amino acids and play crucial roles in antioxidative defense and energy metabolism. The gliadin and glutenin content of BW increased by 12% and 2%, respectively, compared to CW, due to elevated levels of amino acids and their derivatives, whereas GW was notable for its higher globulin content (an increase of 11.6%). BW was also distinguished by its exceptionally high anthocyanin content, including cyanidin-3-O-(6-O-malonyl-beta-D-glucoside) (23.2 μg g-1), cyanidin-3-O-glucoside (6.5 μg g-1), and peonidin-3-O-glucoside (2.3 μg g-1), which surpassed the levels found in both CW and GW (which approached zero). However, BW had lower gluten content, resulting in a greater weakening and reduced development and stability times. Conversely, GW exhibited an increased lipid metabolism, which was associated with a higher starch and gluten content, improving the maximum tensile resistance. Overall, the pigmented wheat varieties offer superior nutritional profiles and processing advantages, necessitating further research to optimize their commercial use.

Application of Supercritical CO2 Extraction and Identification of Polyphenolic Compounds in Three Species of Wild Rose from Kamchatka: Rosa acicularis, Rosa amblyotis, and Rosa rugosa

A comparative metabolomic study of three varieties of wild Rosa (Rosa acicularis, Rosa amblyotis, and Rosa rugosa) from a Kamchatka expedition (2024) was conducted via extraction with supercritical carbon dioxide modified with ethanol (EtOH), and detection of bioactive compounds was realized via tandem mass spectrometry. Several experimental conditions were investigated in the pressure range 50-350 bar, with the used volume of co-solvent ethanol in the amount of 2% in the liquid phase at a temperature in the range of 31-70 °C. The most effective extraction conditions are the following: pressure 200 Bar and temperature 55 °C for Rosa acicularis; pressure 250 Bar and temperature 60 °C for Rosa amblyotis; pressure 200 Bar and temperature 60 °C for Rosa rugosa. Three varieties of wild Rosa contain various phenolic compounds and compounds of other chemical groups with valuable biological activity. Tandem mass spectrometry (HPLC-ESI-ion trap) was applied to detect the target analytes. A total of 283 bioactive compounds (two hundred seventeen compounds from the polyphenol group and sixty-six compounds from other chemical groups) were tentatively identified in extracts from berries of wild Rosa. For the first time, forty-eight chemical constituents from the polyphenol group (15 flavones, 14 flavonols, 4 flavan-3-ols, 3 flavanones, 1 phenylpropanoid, 2 gallotannins, 1 ellagitannin, 4 phenolic acids, 1 dihydrochalcone, and 3 coumarins) were identified in supercritical extracts of R. acicularis, R. amblyotis, and R. rugosa.

Using VIS-NIR hyperspectral imaging and deep learning for non-destructive high-throughput quantification and visualization of nutrients in wheat grains

High-throughput and low-cost quantification of the nutrient content in crop grains is crucial for food processing and nutritional research. However, traditional methods are time-consuming and destructive. A high-throughput and low-cost method of quantification of wheat nutrients with VIS-NIR (400-1700 nm) hyperspectral imaging is proposed in this study. Stepwise linear regression (SLR) was used to predict hundreds of nutrients accurately (R2 > 0.6); results improved when the hyperspectral data was processed with the first derivative. Knockout materials were also used to verify their practical application value. Various nutrients' characteristic wavelengths were mainly concentrated in the visible regions of 400-500 nm and 900-1000 nm. Finally, we proposed an improved pix2pix conditional generative network model to visualize the nutrients distribution and showed better results compared with the original. This research highlights the potential of hyperspectral technology in high-throughput and non-destructive determination and visualization of grain nutrients with deep learning.

Genus Ribes: Ribes aureum, Ribes pauciflorum, Ribes triste, and Ribes dikuscha-Comparative Mass Spectrometric Study of Polyphenolic Composition and Other Bioactive Constituents

This study presents the metabolomic profiles of the four Ribes species (Ribes pauciflorum Turcz., Ribes triste Pall., Ribes dicuscha Fisch., and Ribes aureum Purch.). The plant material was collected during two expeditions in the Russian Far East. Tandem mass spectrometry was used to detect target analytes. A total of 205 bioactive compounds (155 compounds from polyphenol group and 50 compounds from other chemical groups) were tentatively identified from the berries and extracts of the four Ribes species. For the first time, 29 chemical constituents from the polyphenol group were tentatively identified in the genus Ribes. The newly identified polyphenols include flavones, flavonols, flavan-3-ols, lignans, coumarins, stilbenes, and others. The other newly detected compounds in Ribes species are the naphthoquinone group (1,8-dihydroxy-anthraquinone, 1,3,6,8-tetrahydroxy-9(10H)-anthracenone, 8,8'-dihydroxy-2,2'-binaphthalene-1,1',4,4'-tetrone, etc.), polyhydroxycarboxylic acids, omega-3 fatty acids (stearidonic acid, linolenic acid), and others. Our results imply that Ribes species are rich in polyphenols, especially flavanols, anthocyanins, flavones, and flavan-3-ols. These results indicate the utility of Ribes species for the health and pharmaceutical industry.

Identification of crucial metabolites in colored grain wheat (Triticum aestivum L.) regulated by nitrogen application

Colored wheats have drawn attention due to their nutritional compounds. However, limited information is obtained on the effects of nitrogen fertilizer on crucial metabolites and grain quality of wheats with different color grain. In the study, the pot experiment was conducted with white (W), blue (B), and purple (P) grain wheats treated with three levels of N (LN, 0 g kg-1; MN, 0.05 g kg-1; HN, 0.1 g kg-1). Higher N level could promote wheat growth, improve grain indexes, and nutrient uptake. SPAD values of flag leaves remained in the order HN > MN > LN across all wheat varieties, and maintained increasing during tested stages under purple wheat. Metabolomics analysis showed that the annotated 358 metabolites mainly belonged to 29 classes, including carboxylic acids and their derivatives, fatty acids, flavonoids, and phenols. 35, 39, and 70 differential accumulated metabolites were respectively found between the WLN vs. WHN, the BHN vs. BLN, and the PHN vs. PLN, which were mainly enriched in "biosynthesis of plant secondary metabolites", "cGMP-PKG signaling pathway", "sphingolipid signaling pathway", "biosynthesis of alkaloids derived from histidine and purine", and "biosynthesis of plant hormones". Additionally, erucic acid was dominated in the three wheat cultivars, and was decreased after treated with high N levels. Our study preliminarily revealed the different response mechanisms to different N levels in the white, blue, and purple grain wheats, and lay a theoretical foundation for further breeding of excellent colored grain varieties.

Metabolomics Uncovers the Mechanisms of Nitrogen Response to Anthocyanins Synthesis and Grain Quality of Colored Grain Wheat (Triticum aestivum L.)

Nitrogen (N) is a key factor for plant growth and affects anthocyanin synthesis. This study aimed to clarify the potential mechanisms of N levels (LN, 0 kg·ha-1; MN, 150 kg·ha-1; HN, 225 kg·ha-1) in anthocyanin synthesis and grain quality of colored grain wheat. HN increased the yield component traits and grain morphology traits in colored grain wheat while decreasing the processing and nutrient quality traits. Most quality traits were significantly negatively correlated with the yield composition and morphological traits. Anthocyanin was more accumulated under LN conditions, but other related yield and morphological traits of colored grain wheat declined. The anthocyanin content was the highest in blue wheat, followed by that in purple wheat. Cyanidin-3-O-(6-O-malonyl-β-d-glucoside) and cyanidin-3-O-rutinoside were the predominant anthocyanins in blue and purple wheat. The identified anthocyanin-related metabolites were associated with flavonoid biosynthesis, anthocyanin biosynthesis, and secondary metabolite biosynthesis. Therefore, the study provided information for optimizing nitrogen fertilizer management in producing high quality colored wheat and verified the close relationship between anthocyanin and low N condition.

Dietary polyphenols regulate appetite mechanism via gut-brain axis and gut homeostasis

Nowadays, due to the rise of fast-food consumption, the metabolic diseases are increasing as a result of high-sugar and high-fat diets. Therefore, there is an urgent need for natural, healthy and side-effect-free diets in daily life. Whole grain supplementation can enhance satiety and regulate energy metabolism, effects that have been attributed to polyphenol content. Dietary polyphenols interact with gut microbiota to produce intermediate metabolites that can regulate appetite while also enhancing prebiotic effects. This review considers how interactions between gut metabolites and dietary polyphenols might regulate appetite by acting on the gut-brain axis. In addition, further advances in the study of dietary polyphenols and gut microbial metabolites on energy metabolism and gut homeostasis are summarized. This review contributes to a better understanding of how dietary polyphenols regulate appetite via the gut-brain axis, thereby providing nutritional references for citizens' dietary preferences.

Changes in physio-biochemical metabolism, phenolics and antioxidant capacity during germination of different wheat varieties

Changes in physio-biochemical metabolism, phenolics and antioxidant capacity during germination were studied in eight different wheat varieties. Results showed that germination enhanced sprout growth, and caused oxidative damage, but enhanced phenolics accumulation. Ferulic acid and p-coumaric acid were the main phenolic acids in wheat sprouts, and dihydroquercetin, quercetin and vitexin were the main flavonoids. The phenolic acid content of Jimai 44 was the highest on the 2th and 4th day of germination, and that of Bainong 307 was the highest on the 6th day. The flavonoid content of Hei jingang was the highest during whole germination. The enzymes activities of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H) and 4-coumarate coenzyme A ligase (4CL) were up-regulated. The activities of catalase, polyphenol oxidase and peroxidase were also activated. Antioxidant capacity of wheat sprouts was enhanced. The results provided new ideas for the production of naturally sourced phenolic rich foods.

Integrative metabolome and transcriptome profiling provide insights into elucidation of the synthetic mechanisms of phenolic compounds in Yunnan hulled wheat (Triticum aestivum ssp. yunnanense King)

BACKGROUND

Yunnan hulled wheat grains (YHWs) have abundant phenolic compounds (PCs). However, a systematic elucidation of the phenolic characteristics and molecular basis in YHWs is currently lacking. The aim of the study, for the first time, was to conduct metabolomic and transcriptomic analyses of YHWs at different developmental stages.

RESULTS

A total of five phenolic metabolite classes (phenolic acids, flavonoids, quinones, lignans and coumarins, and tannins) and 361 PCs were identified, with flavonoids and phenolic acids being the most abundant components. The relative abundance of the identified PCs showed a dynamic decreasing pattern with grain development, and the most significant differences in accumulation were between the enlargement and mature stage, which is consistent with the gene regulation patterns of the corresponding phenolic biosynthesis pathway. Through co-expression and co-network analysis, PAL, HCT, CCR, F3H, CHS, CHI and bZIP were identified and predicted as candidate key enzymes and transcription factors.

CONCLUSION

The results broaden our understanding of PC accumulation in wheat whole grains, especially the differential transfer between immature and mature grains. The identified PCs and potential regulatory factors provide important information for future in-depth research on the biosynthesis of PCs and the improvement of wheat nutritional quality. © 2024 Society of Chemical Industry.

Metabolome and Transcriptome Association Analysis Reveals Mechanism of Synthesis of Nutrient Composition in Quinoa (Chenopodium quinoa Willd.) Seeds

Quinoa (Chenopodium quinoa Willd.) seeds are rich in nutrition, superior to other grains, and have a high market value. However, the biosynthesis mechanisms of protein, starch, and lipid in quinoa grain are still unclear. The objective of this study was to ascertain the nutritional constituents of white, yellow, red, and black quinoa seeds and to employ a multi-omics approach to analyze the synthesis mechanisms of these nutrients. The findings are intended to furnish a theoretical foundation and technical support for the biological breeding of quinoa in China. In this study, the nutritional analysis of white, yellow, red, and black quinoa seeds from the same area showed that the nutritional contents of the quinoa seeds were significantly different, and the protein content increased with the deepening of color. The protein content of black quinoa was the highest (16.1 g/100 g) and the lipid content was the lowest (2.7 g/100 g), among which, linoleic acid was the main fatty acid. A combined transcriptome and metabolome analysis exhibited that differentially expressed genes were enriched in "linoleic acid metabolism", "unsaturated fatty acid biosynthesis", and "amino acid biosynthesis". We mainly identified seven genes involved in starch synthesis (LOC110716805, LOC110722789, LOC110738785, LOC110720405, LOC110730081, LOC110692055, and LOC110732328); five genes involved in lipid synthesis (LOC110701563, LOC110699636, LOC110709273, LOC110715590, and LOC110728838); and nine genes involved in protein synthesis (LOC110710842, LOC110720003, LOC110687170, LOC110716004, LOC110702086, LOC110724454 LOC110724577, LOC110704171, and LOC110686607). The data presented in this study based on nutrient, transcriptome, and metabolome analyses contribute to an enhanced understanding of the genetic regulation of seed quality traits in quinoa, and provide candidate genes for further genetic improvements to improve the nutritional value of quinoa seeds.

Transcriptome, Plant Hormone, and Metabolome Analysis Reveals the Mechanism of Purple Pericarp Formation in 'Zihui' Papaya (Carica papaya L.)

The color of the pericarp is a crucial characteristic that influences the marketability of papaya fruit. Prior to ripening, normal papaya exhibits a green pericarp, whereas the cultivar 'Zihui' displays purple ring spots on the fruit tip, which significantly affects the fruit's visual appeal. To understand the mechanism behind the formation of purple pericarp, this study performed a thorough examination of the transcriptome, plant hormone, and metabolome. Based on the UPLC-ESI-MS/MS system, a total of 35 anthocyanins and 11 plant hormones were identified, with 27 anthocyanins and two plant hormones exhibiting higher levels of abundance in the purple pericarp. In the purple pericarp, 14 anthocyanin synthesis genes were up-regulated, including CHS, CHI, F3H, F3'5'H, F3'H, ANS, OMT, and CYP73A. Additionally, through co-expression network analysis, three MYBs were identified as potential key regulators of anthocyanin synthesis by controlling genes encoding anthocyanin biosynthesis. As a result, we have identified numerous key genes involved in anthocyanin synthesis and developed new insights into how the purple pericarp of papaya is formed.

Metabolic profiling provides insights into the accumulation patterns of flavonoids and phenolic acids in different parts of Lactuca indica L

Lactuca indica L. contains high amounts of flavonoids and phenolic acids. However, there is limited information on the composition of these compounds in different parts of the plant. The present study analyzed the secondary metabolite profiles of the stem, leaf, flower, and seed of Lactuca indicaL.cv. Mengzao (LIM) using a widely targeted metabolomic approach. A total of 576 secondary metabolites were identified, including 218, 267, 232, 286, 302, and 308 differentially accumulated metabolites (DAMs) in the stem_vs_leaf, stem_vs_flower, stem_vs_seed, leaf_vs_flower, leaf_vs_seed, and flower_vs_seed comparisons. In particular, considerable differences were detected in the flavonoids and phenolic acids, five flavonoids, five phenolic acids, one triterpenoid and one alkaloid being differentially accumulated in the four parts. Compared to the stem and flower, the leaf and seed had higher total flavonoid content and total phenolic content. Thses findings provide comprehensive insights into utilizing different parts of LIM in developing functional food products.

Antioxidant Properties and Geroprotective Potential of Wheat Bran Extracts with Increased Content of Anthocyanins

In recent years, there has been a focus on breeding wheat with high anthocyanin levels in order to improve food quality and human health. The objective of this study was to examine the antioxidant and geroprotective properties of wheat bran extracts using both in vitro and in vivo research methods. Two wheat lines were used: one with uncolored pericarp (anthocyanin-free) and another with colored pericarp (anthocyanin-containing). These lines differed in a specific region of chromosome 2A containing the Pp3/TaMyc1 gene, which regulates anthocyanin production. High-performance liquid chromatography-mass spectrometry revealed the presence of cyanidin glucoside and cyanidin arabinoside in the anthocyanin-containing wheat bran extract (+AWBE), while no anthocyanins were found in the anthocyanin-free wheat bran extract (-AWBE). The +AWBE showed higher radical scavenging activity (DPPH and ABTS assays) and membrane protective activity (AAPH oxidative hemolysis model) compared to the -AWBE. Both extracts extended the lifespan of female Drosophila, indicating geroprotective properties. This study demonstrates that wheat bran extracts with high anthocyanin levels have antioxidant and geroprotective effects. However, other secondary metabolites in wheat bran can also contribute to its antioxidant and geroprotective potential.

Uncovering the phenolic diversity of Guabiju fruit: LC-MS/MS-based targeted metabolomics approach

The comprehensive composition of phenolic compounds (PC) from seven genotypes of guabiju were analyzed by high-performance liquid chromatography coupled to a diode array detector and mass spectrometry (HPLC-ESI-qTOF-MS/MS), and a targeted metabolomic approach was utilized to explore the PC-related similarities among the genotypes. Sixty-seven phenolic compounds were annotated and twenty-four were quantified in all genotypes of guabiju. The phenolic acids and anthocyanins were the major PC, representing more than 63% (w/w) of the total PC. Di-O-galloylquinic and tri-O-galloylquinic acids and ellagitannins were reported for the first time in guabiju. The results of hierarchical clustering and principal components analysis (PCA) suggested seven groups as suitable clusters to be formed according to phenolic composition. Eleven PC were selected as relevant for sample clustering, and six of them were highlighted as the most informative (in decreasing order of importance): epicatechin, catechin, (epi)gallocatechin gallate II, di-O-galloylquinic acid I, tri-O-galloylquinic acid and delphinidin 3-O-glucoside. To the best of our knowledge, this study contributes to the literature with the most complete phenolic profile of guabiju genotypes up to date. Moreover, guabiju susceptibility to fungal infestation related to PC composition was briefly discussed based on a parallel study using the same genotypes.

Elucidating the Differentiation Synthesis Mechanisms of Differently Colored Resistance Quinoa Seedings Using Metabolite Profiling and Transcriptome Analysis

Quinoa (Chenopodium quinoa wild.), a dicotyledonous plant native to the Andes, is an increasingly popular pseudograin owing to its high nutritional value, stress resistance capabilities, and gluten-free properties. In this study, we aimed to explore the dynamic changes in different varieties of quinoa at the seedling stage and their regulatory networks. Here, we found that the leaves of quinoa showed obvious coloration after 45 days, and four quinoa seedling types (red, white, yellow, and black) were subjected to ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and transcriptome sequencing to identify their differentially expressed genes and metabolites. A total of 29 differential metabolites and 19 genes (14 structural and 5 regulatory genes) were identified, and consistent differences were observed in the flavonoid, phenolic acid, and alkaloid metabolites in the different quinoa types. These differential metabolites were significantly enriched in flavonoid and flavonol biosynthesis, flavonoid biosynthesis, and phenylpropanoid biosynthesis pathways. In addition, real-time fluorescence quantitative PCR (RT-qPCR) technology was used to detect the expression of four structural genes involved in the flavonoid biosynthesis pathway and four regulatory genes (interaction network). The results revealed that the structural and regulatory gene transcript levels in the flavonoid pathway were higher in the red quinoa cultivars than in the white, yellow, and black. Additionally, the differences in the leaves of these four quinoa cultivars were mainly due to differences in flavonoid, phenolic acid, and alkaloid accumulation. Our findings provide a basis for understanding the accumulation and coloration mechanisms of flavonoids, phenolic acids, and alkaloids in quinoa seedlings of different colors and also provide a theoretical basis for future investigations.

Influence of Agronomic Practices on the Antioxidant Compounds of Pigmented Wheat (Triticum aestivum spp. aestivum L.) and Tritordeum (× Tritordeum martinii A. Pujadas, nothosp. nov.) Genotypes

Twelve pigmented wheat genotypes, one tritordeum, and one common wheat were grown in three field experiments under varying nitrogen (N) fertilization rates to investigate the contributions of genotype, environment, and fertilization on the levels of phenolic acids, anthocyanins, carotenoids and antioxidant capacity of the grains. Soluble phenolic acids increased significantly (+16%) in the environment with high soil N content, while bound phenolic acids and anthocyanins decreased (-16 and -57%). N fertilization affected the agronomic and qualitative traits but had limited effects on some bioactive compounds (bound phenolic acids and anthocyanins). The greatest differences appeared among the color groups and within the same color types, with the black group showing the most anthocyanins and phenolic acids (34.4 and 1207 mg·kg-1) and the highest antioxidant capacity. Some of the cultivars could be promising for the development of innovative supply chains and the production of functional foods, as they showed good yield and quality performances, and good antioxidant features.

Integrated Metabolome and Transcriptome Analyses Reveal Amino Acid Biosynthesis Mechanisms during the Physiological Maturity of Grains in Yunnan Hulled Wheat (Triticum aestivum ssp. yunnanense King)

Yunnan hulled wheat (YHW) possesses excellent nutritional characteristics; however, the precise amino acid (AA) composition, contents, and molecular mechanisms underlying AA biosynthesis in YHW grains remain unclear. In this study, we aimed to perform metabolomic and transcriptomic profiling to identify the composition and genetic factors regulating AA biosynthesis during the physiological maturation of grains of two YHW genotypes, Yunmai and Dikemail, with high and low grain protein contents, respectively. A total of 40 and 14 differentially accumulated amino acids (AAs) or AA derivatives were identified between the waxy grain (WG) and mature grain (MG) phenological stages of Yunmai and Dikemail, respectively. The AA composition differed between WG and MG, and the abundance of AAs-especially that of essential AAs-was significantly higher in WG than in MG (only 38.74-58.26% of WG). Transcriptome analysis revealed differential regulation of structural genes associated with the relatively higher accumulation of AAs in WG. Weighted gene co-expression network analysis and correlation analyses of WG and MG indicated differences in the expression of clusters of genes encoding both upstream elements of AA biosynthesis and enzymes that are directly involved in AA synthesis. The expression of these genes directly impacted the synthesis of various AAs. Together, these results contribute to our understanding of the mechanism of AA biosynthesis during the different developmental stages of grains and provide a foundation for further research to improve the nutritional value of wheat products.

Characterization Variation of the Differential Coloring Substances in Rapeseed Petals with Different Colors Using UPLC-HESI-MS/MS

Rapeseed's (Brassica napus L.) colorful petals have important ornamental values. However, the mechanisms of regulating petals coloration in rapeseed are still unknown. In our study, we investigated the key differential coloring substances in nine rapeseed cultivars with different petal colors, and 543 metabolites were detected and characterized through UPLC-HESI-MS/MS. Among them, the kinds and contents of flavonols, flavones, and anthocyanidins were the main contributors to petals' coloration. Tamarixetin-, quercetin-, butin-, naringenin- and luteolin-derivates were the main pigment bases in white and yellow petals. Peonidin-3,5-O-diglucoside, peonidin-3-O-(6″-O-caffeoyl)glucoside, and quercetin-derivatives were the main coloring substances in pink petals. Acylated cyanidin derivatives might lead to a series of different purple petal colors. Glycosylated anthocyanins were responsible for the coloration of rapeseed red petals, and peonidin-3-O-glucoside and kaempferol-derivatives were mainly detected from the red petals. These results provide comprehensive insights into the difference in flavonoid metabolites in rapeseed petals with different colors and supply theoretical supports for the breeding of novel colorful rapeseed cultivars.

Phenolic metabolites as therapeutic in inflammation and neoplasms: molecular pathways explaining their efficacy

Polyphenols, also known as phenolic compounds, are chemical substances containing aromatic rings as well as at least two hydroxyl groups. Natural phenolic compounds exist widely in plants, which protect plants from ultraviolet radiation and other insults. Phenolic compounds have superior pharmacological and nutritional properties (antimicrobial, antibacterial, antiviral, anti-sclerosis, antioxidant, and anti-inflammatory activities), which have been paid more and more attention by the scientific community. Phenols can protect key cellular components from reactive free radical damage, which is mainly due to their property to activate antioxidant enzymes and alleviate oxidative stress and inflammation. It can also inhibit or isolate reactive oxygen species and transfer electrons to free radicals, thereby avoiding cell damage. It has a regulatory role in glucose metabolism, which has a promising prospect in the prevention and intervention of diabetes. It also prevents cardiovascular disease by regulating blood pressure and blood lipids. Polyphenols can inhibit cell proliferation by affecting Erk1/2, CDK, and PI3K/Akt signaling pathways. Polyphenols can function as enhancers of intrinsic defense systems, including superoxide dismutase (SOD) and glutathione peroxidase (GPX). Simultaneously, they can modulate multiple proteins and transcription factors, making them promising candidates in the investigation of anti-cancer medications. This review focuses on multiple aspects of phenolic substances, including their natural origins, production process, disinfection activity, oxidative and anti-inflammatory functions, and the effects of different phenolic substances on tumors.

A multi-omic resource of wheat seed tissues for nutrient deposition and improvement for human health

As a globally important staple crop, wheat seeds provide us with nutrients and proteins. The trend of healthy dietary has become popular recently, emphasizing the consumption of whole-grain wheat products and the dietary benefits. However, the dynamic changes in nutritional profiles of different wheat seed regions (i.e., the embryo, endosperm and outer layers) during developmental stages and the molecular regulation have not been well studied. Here, we provide this multi-omic resource of wheat seeds and describe the generation, technical assessment and preliminary analyses. This resource includes a time-series RNA-seq dataset of the embryo, endosperm and outer layers of wheat seeds and their corresponding metabolomic dataset, covering the middle and late stages of seed development. Our RNA-seq experiments profile the expression of 63,708 genes, while the metabolomic data includes the abundance of 984 metabolites. We believe that this was the first reported transcriptome and metabolome dataset of wheat seeds that helps understand the molecular regulation of the deposition of beneficial nutrients and hence improvements for nutritional and processing quality traits.

Metabolome and transcriptome analyses of anthocyanin biosynthesis reveal key metabolites and candidate genes in purple wheat (Triticum aestivum L.)

Wheat (Triticum aestivum L.) is continuously subjected to genetic improvement to optimize grain quality. Purple wheat has recently gained attention because of its high anthocyanin and nutrient content. In this study, we performed an integrated transcriptome and metabolome analysis of the inbred wheat lines ZM152 (white wheat line) and ZM163 (purple wheat line) to elucidate molecular networks and identify potential genes regulating anthocyanin synthesis. A total of 564 metabolites were detected, of which 47 metabolite contents differed significantly between the two lines. Twenty-five flavonoids, including four anthocyanins, were significantly higher in purple wheat. High contents of cyanidin 3-rutinoside and malvidin 3-glucoside might contribute to the purple coloration of the wheat grains. Consistently, gene ontology and pathway enrichment analyses revealed that flavonoid and anthocyanin biosynthesis were mostly enriched, and the expression of anthocyanin structural genes was specifically upregulated in purple wheat lines, while transcription factors (TFs) were mostly downregulated in purple wheat lines. Especially, the correlation analysis showed the anthocyanin synthesis-related genes CHS (TraesCS2B02G048400) and UFGT (TraesCS7A02G155400) were likely regulated negatively by the TFs MYB4 (TraesCS1A02G268800, TraesCS1B02G279400), TT8 (TraesCS1D02G094200, TraesCS1B02G113100, and TraesCS1A02G102400), which thus could be considered important regulatory genes in the anthocyanin biosynthesis pathway of purple wheat lines. In summary, these results offer new insights into anthocyanin biosynthesis and accumulation of purple wheat, and provide very useful candidate genes for future colored wheat breeding.

Comparative Characterization of Fruit Volatiles and Volatile-Related Genes Expression of 'Benihoppe' Strawberry and Its Somaclonal Mutant

Somaclonal variations in tissue cultures can be used in plant breeding programs. However, it is still unclear whether somaclonal variations and their original parent have differences in volatile compounds, and the candidate genes which result in the differences in volatile compounds also need to be identified. In this study, we utilized the 'Benihoppe' strawberry and its somaclonal mutant 'Xiaobai', which has different fruit aromas compared with 'Benihoppe', as research materials. Using HS-SPME-GC-MS, 113 volatile compounds have been identified in the four developmental periods of 'Benihoppe' and 'Xiaobai'. Among them, the quantity and content of some unique esters in 'Xiaobai' were much higher than that in 'Benihoppe'. In addition, we found that the contents and odor activity values of ethyl isovalerate, ethyl hexanoate, ethyl butyrate, ethyl pentanoate, linalool, and nerolidol in the red fruit of 'Xiaobai' were much higher compared with 'Benihoppe', which may result from the significantly increased expression of FaLOX6, FaHPL, FaADH, FaAAT, FaAAT1, FaDXS, FaMCS, and FaHDR in 'Xiaobai'. However, the content of eugenol in 'Benihoppe' was higher than that in 'Xiaobai', which may result from the higher expression of FaEGS1a in 'Benihoppe' compared with 'Xiaobai'. The results provide insights into the somaclonal variations that affect the volatile compounds in strawberries and can be used for strawberry quality improvement.

Metabolomic Analysis Reveals Patterns of Whole Wheat and Pearling Fraction Flour Quality Response to Nitrogen in Two Wheat Lines with Contrasting Protein Content

Nitrogen (N) application increases wheat yield and protein content and affects the nutritional quality of the grain. Analysis of N use efficiency revealed that N uptake efficiency is a key factor affecting protein content. Two wheat lines with significant differences in protein content were used to investigate the response of differential accumulation of metabolites to N levels and the spatial variation pattern of metabolites related to nutritional quality in wheat grains using widely targeted metabolomics analysis. The results showed that amino acids, nucleic acids, and phytohormones and their derivatives and glycolytic processes are the crucial factors affecting protein content in two wheat lines. Amino acids and derivatives, lipids, and flavonoids are the main contributors to metabolite spatial variation of grains, which were interactively regulated by nitrogen and genotypes. N application significantly increased the relative accumulation of beneficial bioactive substances in the inner layer (P3 to P5), but excessive N application may inhibit this effect and lead to poor nutritional quality.

Metabolomics analysis reveals the accumulation patterns of flavonoids and phenolic acids in quinoa (Chenopodium quinoa Willd.) grains of different colors

Quinoa grains are gaining increasing popularity owing to their high nutritional merits. However, only limited information is available on the metabolic profiles of quinoa grains. In this study, we determined the metabolic profiles of black, red, and white quinoa grains via an ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics. A total of 689 metabolites were identified, among which 251, 182, and 317 metabolites displayed different accumulation patterns in the three comparison groups (Black vs Red, Black vs White, and Red vs White), respectively. In particular, flavonoid and phenolic acid contents displayed considerable differences, with 22 flavonoids, 5 phenolic acids, and 1 betacyanin being differentially accumulated among the three quinoa cultivars. Additionally, correlation analysis showed that flavonoids and phenolic acids could act as betanin co-pigments in quinoa grains. In conclusion, this study provides comprehensive insights into the adequate utilization and development of novel quinoa-based functional foods.

Omics data reveals the phenolic fingerprint of Brazilian whole wheat flours of different technological qualities

Common wheat (Triticum aestivum) is one of the most consumed staple foods used for bakery products. Outer layers of grain present a great diversity of bioactive compounds, especially phenolic compounds (PC). Free and bound PC were extracted from eight genotypes of whole wheat flours (WWF) presenting different technological classifications. These extracts were comprehensively characterized through untargeted metabolomics applying ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MSE) and spectrophotometric analyses. Chemical composition and colorimetry were also determined by classical analyses. Thirty-eight PC were tentatively identified by UHPLC-MSE belonging to three classes (phenolic acids, flavonoids, and other polyphenols), some of them identified in all WWF samples. Bound hydroxycinnamic acids were the main PC found in WWF, especially the trans-ferulic acid and its isomer. No difference was found in starch and protein contents, whereas low-quality flours showed a higher ash content than the superior and medium-quality flours. Total phenolic content (TPC) ranged between 124.5 and 171.4 mg GAE/100 g WWF, which bound PC were responsible for 60% of TPC. Omics data and multivariate statistical analyses were successfully applied to discern the phenolic profile of WWF from different genotypes and technological qualities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05665-8.

Protective effect of astragalus membranaceus and its bioactive compounds against the intestinal inflammation in Drosophila

Inflammatory bowel disease (IBD) is characterized by chronic and relapsing intestinal inflammation, which currently lacks safe and effective medicines. Astragalus membranaceus (AM), also named Huangqi, is one of the most commonly used fundamental herbs in China. Here, we aimed to investigate mechanism and bioactive compounds of AM on treating sodium dodecyl sulfate (SDS)- induced colitis in Drosophila flies. Our data showed that AM extract (AME) supplementation had no toxic effect in flies, and protected flies against SDS-induced lifespan shortening, intestinal morphological damage, and colon length shortening. Moreover, AME supplementation remarkably rescued SDS-induced intestinal stem cell (ISC) overproliferation and increased reactive oxygen species (ROS) level in the intestine. Mechanistically, AME remarkably rescued the altered expression levels of genes and proteins in c-Jun N-terminal kinase (JNK) and JAK-STAT signaling pathways induced by SDS in gut. Additionally, formononetin, isoliquiritigenin, isorhamnetin, astragaloside I, astragaloside III, vanillic acid, and caffeic acid in AM had protection against SDS-induced inflammatory damage in flies. Taken together, AME could ameliorate the intestinal inflammation partially by suppressing oxidative stress-associated JNK signaling and JAK-STAT signaling pathways. AME may provide a theoretical basis for natural medicine toward treating intestinal inflammatory disease in human.

Proteomic and Metabolomic Revealed Differences in the Distribution and Synthesis Mechanism of Aroma Precursors in Yunyan 87 Tobacco Leaf, Stem, and Root at the Seedling Stage

Tobacco, as an important cash crop and model plant, has been the subject of various types of research. The quality of flue-cured tobacco products depends on the compound collection of tobacco leaves, including pigments, carbohydrates, amino acids, polyphenols, and alkaloid aroma precursors. The present study investigates tobacco seedling organs (leaf, stem, and root) with the assistance of label-free proteomic technology and untargeted metabonomic technology. We analyzed 4992 proteins and 298 metabolites obtained in the leaf, stem, and root groups and found that there were significant differences in both primary and secondary metabolism processes involved in aroma precursor biosynthesis, such as carbohydrate metabolism, energy metabolism, and amino acid biosynthesis, and phenylpropanoid, flavonoid, and alkaloid biosynthesis. The findings showed that the contents of alkaloid metabolites such as nornicotine, anatabine, anatalline, and myosmine were significantly higher in tobacco roots than in leaves and stems at the seedling stage.

Colored wheat and derived products: key to global nutritional security

Ensuring food and nutritional security of fast-growing population will pose a huge challenge in future. An estimated one-half population who does not go hungry, nonetheless suffers the debilitating effects of unhealthy diets. In view of the nutritional awareness, when the major wheat breeding programs have started shifting to quality, instead of quantity in wheat, the colored wheats give a novel twist of targeting the malnutrition by enhancing the antioxidants such as anthocyanin, carotenoids, flavonoids, polyphenols etc. Moreover, changing consumer demands have picked the trend to prefer a nutritionally balanced diet over the conventional high energy diets and thus, colored wheat has opened up a hidden avenue for providing additional value to the wheat-based products. Besides providing nutrition, these pigments have the potential to replace the synthetic dyes and food colorants prevalent in the market. The review summarizes the genetics and biochemistry of the pigments of colored wheat along with their product development, nutritional status and consumer preference. The review also sheds light on the environmental effect on color accumulation and the effect of increased colorants on other quality traits of wheat.

Flos puerariae ameliorates the intestinal inflammation of Drosophila via modulating the Nrf2/Keap1, JAK-STAT and Wnt signaling

Gut homeostasis is important for human health, and its disruption can lead to inflammatory bowel disease (IBD). Flos Puerariae is a herb with a wide variety of pharmacological activities including antioxidant, antidiabetic, antialcoholismic and anti-inflammatory properties. However, the role of Flos Puerariae on treating IBD remains obscure. Here, we employed Drosophila melanogaster as a model organism to investigate the protective effect of Flos Puerariae extract (FPE) against sodium dodecyl sulfate (SDS)-induced intestinal injury. Our data showed that FPE had no toxic effect in flies, and significantly extended lifespan in SDS-inflamed flies, reduced stem cell proliferation in the midgut, and maintained intestinal morphological integrity. Furthermore, FPE remarkably recused the altered expression level of genes and proteins in Nrf2/Keap1 signaling, JAK-STAT signaling and Wnt signaling pathways in gut of inflammation flies. Thus, FPE has a protective effect against intestinal injury possibly via increasing the Nrf2/keap1 pathway and suppressing the JAK-STAT and Wnt signaling pathways, which would have tremendous potential for treating IBD.

Metabolomics based inferences to unravel phenolic compound diversity in cereals and its implications for human gut health

Background

Scope and approach

Key findings and conclusion

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Phenolic compounds are critical in avoiding metabolic disorders associated with oxidative stress.

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Breeding cereal crops to enrich phenolic compounds in grains contributes to personalized nutrition.

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A diet rich in cereal phenolics likely to increase human gut health, thereby lowering the risk of non-communicable illness.

Rising Demand for Healthy Foods-Anthocyanin Biofortified Colored Wheat Is a New Research Trend

Wheat is a vital and preferred energy source in many parts of the world. Its unique processing quality helps prepare many products such as bread, biscuit, pasta, and noodles. In the world of rapid economic growth, food security, in terms of nutritional profile, began to receive more significant interest. The development of biofortified colored wheat (black, purple, and blue) adds nutritional and functional health benefits to the energy-rich wheat. Colored wheat exists in three forms, purple, blue, and black, depending upon the types and position of the anthocyanins in wheat layers, regulated by the bHLH-MYC transcription factor. Colored wheat lines with high anthocyanin, iron, and zinc contents showed antioxidant and anti-inflammatory activity and possessed desirable product-making and commercial utilization features. The anthocyanin in colored wheat also has a broad spectrum of health implications, such as protection against metabolic syndromes like obesity, diabetes, hypertension, and dyslipidemia. The idea of developing anthocyanin-biofortified wheat shapes human beings' lifestyles as it is a staple food crop in many parts of the world. This review is a compilation of the currently available information on colored wheat in the critical aspects, including biochemistry, food processing, nutrition, genetics, breeding, and its effect on human health. Market generation and consumer awareness creation are vital challenges for its exploitation as a function food on a large scale.

Flavonoid Biosynthesis Genes in Triticum aestivum L.: Methylation Patterns in Cis-Regulatory Regions of the Duplicated CHI and F3H Genes

Flavonoids are a diverse group of secondary plant metabolites that play an important role in the regulation of plant development and protection against stressors. The biosynthesis of flavonoids occurs through the activity of several enzymes, including chalcone isomerase (CHI) and flavanone 3-hydroxylase (F3H). A functional divergence between some copies of the structural TaCHI and TaF3H genes was previously shown in the allohexaploid bread wheat Triticum aestivum L. (BBAADD genome). We hypothesized that the specific nature of TaCHI and TaF3H expression may be induced by the methylation of the promoter. It was found that the predicted position of CpG islands in the promoter regions of the analyzed genes and the actual location of methylation sites did not match. We found for the first time that differences in the methylation status could affect the expression of TaCHI copies, but not the expression of TaF3Hs. At the same time, we revealed significant differences in the structure of the promoters of only the TaF3H genes, while the TaCHI promoters were highly homologous. We assume that the promoter structure in TaF3Hs primarily affects the change in the nature of gene expression. The data obtained are important for understanding the mechanisms that regulate the synthesis of flavonoids in allopolyploid wheat and show that differences in the structure of promoters have a key effect on gene expression.

A comprehensive review of wheat phytochemicals: From farm to fork and beyond

The health benefits of whole wheat consumption can be partially attributed to wheat's phytochemicals, including phenolic acids, flavonoids, alkylresorcinols, carotenoids, phytosterols, tocopherols, and tocotrienols. It is of increasing interest to produce whole wheat products that are rich in bioactive phytochemicals. This review provides the fundamentals of the chemistry, extraction, and occurrence of wheat phytochemicals and includes critical discussion of several long-lasting issues: (1) the commonly used nomenclature on distribution of wheat phenolic acids, namely, soluble-free, soluble-conjugated, and insoluble-bound phenolic acids; (2) different extraction protocols for wheat phytochemicals; and (3) the chemistry and application of in vitro antioxidant assays. This review further discusses recent advances on the effects of genotypes, environments, field management, and processing techniques including ultrafine grinding, germination, fermentation, enzymatic treatments, thermal treatments, and food processing. These results need to be interpreted with care due to varied sample preparation protocols and limitations of in vitro assays. The bioaccessibility, bioavailability, metabolism, and potential health benefits of wheat phytochemicals are also reviewed. This comprehensive and critical review will benefit scientific researchers in the field of bioactive compounds of cereal grains and also those in the cereal food industry to produce high-quality functional foods.

General Health Benefits and Pharmacological Activities of Triticum aestivum L

Common wheat (Triticum aestivum), one of the world's most consumed cereal grains, is known for its uses in baking and cooking in addition to its medicinal uses. As this plant's medical benefits are enormous and scattered, this narrative review was aimed at describing the pharmacological activities, phytochemistry, and the nutritional values of Triticum aestivum. It is a good source of dietary fiber, resistant starch, phenolic acids, alkylresorcinols, lignans, and diverse antioxidant compounds such as carotenoids, tocopherols and tocotrienols. These constituents provide Triticum aestivum with a wide range of pharmacological properties, including anticancer, antimicrobial, antidiabetic, hypolipemic, antioxidant, laxative, and moisturizing effects. This review summarized the established benefits of wheat in human health, the mode of action, and different clinical, in vitro and in vivo studies for different varieties and cultivars. This review also gives an insight for future research into the better use of this plant as a functional food. More clinical trials, in vivo and in vitro studies are warranted to broaden the knowledge about the effect of Triticum aestivum on nutrition-related diseases prevention, and physical and mental well-being sustenance.

Dynamic Metabolomics and Transcriptomics Analyses for Characterization of Phenolic Compounds and Their Biosynthetic Characteristics in Wheat Grain

Phenolic compounds are important bioactive phytochemicals with potential health benefits. In this study, integrated metabolomics and transcriptomics analysis was used to analyze the metabolites and differentially expressed genes in grains of two wheat cultivars (HPm512 with high antioxidant activity, and ZM22 with low antioxidant activity) during grain development. A total of 188 differentially expressed phenolic components, including 82 phenolic acids, 81 flavonoids, 10 lignans, and 15 other phenolics, were identified in the developing wheat grains, of which apigenin glycosides were identified as the primary flavonoid component. The relative abundance of identified phenolics showed a decreasing trend with grain development. Additionally, 51 differentially expressed phenolic components were identified between HPm512 and ZM22, of which 41 components, including 23 flavonoids, were up-regulated in HPm512. In developing grain, most of the identified differentially expressed genes involved in phenolic accumulation followed a similar trend. Integrated metabolomics and transcriptomics analysis revealed that certain genes encoding structural proteins, glycosyltransferase, and transcription factors were closely related to metabolite accumulation. The relatively higher accumulation of phenolics in HPm512 could be due to up-regulated structural and regulatory genes. A sketch map was drawn to depict the synthetic pathway of identified phenolics and their corresponding genes. This study enhanced the current understanding of the accumulation of phenolics in wheat grains. Besides, active components and their related genes were also identified, providing crucial information for the improvement of wheat's nutritional quality.

Metabolomic analysis of the grain pearling fractions of six bread wheat varieties

Bread wheat is a staple food crop that is consumed worldwide. In this study, using widely targeted LC-MS/MS, we conducted a high-throughput metabolomic analysis and determined the contents and spatial distribution of metabolites in pearled fractions of the dried kernels of six representative bread wheat varieties cultivated in China. Our aim was to explore the cultivars and pearling fractions with a view toward developing functional food products. We accordingly identified notable differences in the nutrient and bioactive metabolomes, and established that the pearling fractions of each cultivar had distinct metabolic profiles. Flavonoids varied the most amongst the cultivars and were found in higher concentration in the outer layers of the grain, but only at low concentrations in the kernel. Data from this study add further evidence of benefits of whole grain wheat consumption but, specifically, medium-gluten and pigmented wheat offer other nutrient and bioactive benefits whole grain products.

The effect of arbuscular mycorrhizal fungi on the phenolic compounds profile, antioxidant activity and grain yields in wheat cultivars growing under hydric stress

BACKGROUND

Hydric stress affects the production of wheat (Triticum aestivum L.) worldwide, making some tools necessary to cope with the decrease in rainfall. A sustainable alternative is the use of arbuscular mycorrhizal fungi (AMF) as biofertilisers. Here, we analysed the effects of AMF strains adapted or non-adapted to hyper-arid conditions on the phenolic profiles and antioxidant activities of wheat grains from two cultivars with contrasting tolerance to osmotic stress (Ilustre, moderately tolerant; and Maxi, tolerant) grown with and without hydric stress.

RESULTS

Eight phenolic compounds were detected, apigenin-C-pentoside-C-hexoside I being the most abundant and showing an increase of 80.5% when inoculated with the fungus Funneliformis mosseae (FM) obtained from Atacama Desert under normal irrigation with respect to non-mycorrhizal (NM) plants. NM treatments were associated with higher grain yields. FM showed a noticeable effect on most phenolic compounds, with an increase up to 30.2% in apigenin-C-pentoside-C-hexoside III concentration under hydric stress with respect to normal irrigation, being also responsible for high antioxidant activities such as ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) activities.

CONCLUSION

Inoculation with FM adapted to hydric stress produced improvements in phenolics composition and antioxidant activities in grains from wheat plants growing under hydric stress conditions, improving their food quality and supporting the development of further studies to determine whether the use of adapted AMF could be a realistic tool to improve grain quality in a scenario of increasing hydric stress conditions. © 2021 Society of Chemical Industry.

Physiological and molecular response of colored wheat seedlings against phosphate deficiency is linked to accumulation of distinct anthocyanins

Anthocyanin rich colored wheat with additional health benefits has created interest among breeders, consumers and policy makers to address the prevailing malnutrition in the vulnerable population. Researchers are exploring how colored wheat could perform under different nutrient conditions for the maintenance of growth and development. The present study was aimed to investigate the differential response of phosphorous (Pi) deficiency at the seedling stage using hydroponics. Our results showed that Pi-deficiency triggered typical response in the wheat along with the changes in the plant root morphology, total biomass, micronutrient concentration and distinct anthocyanin accumulation. Our physiological and biochemical data revealed that these parameters were positively altered under stress in the colored wheat and the adaptation followed the trend of white < blue <purple < black. Our results also confirmed that stress induced accumulation of distinct anthocyanins including derivatives of cyanidin, delphinidin and peonidin in a genotype dependent manner. Differential expression pattern visualized for the transcripts encoding phosphate transporters, anthocyanin biosynthesis, putative transporters and regulators may be one of the underlying factors. Altogether, our data showed that the black wheat genotype with highest anthocyanin content could able to adapt better with the P stress. This study will help in identifying suitable colored wheat adapting the stress condition and have potential for influence on the future agricultural cultivation practices.

Food Processing Technologies to Develop Functional Foods With Enriched Bioactive Phenolic Compounds in Cereals

Cereal grains and products provide calories globally. The health benefits of cereals attributed to their diverse phenolic constituents have not been systematically explored. Post-harvest processing, such as drying, storing, and milling cereals, can alter the phenolic concentration and influence the antioxidant activity. Furthermore, cooking has been shown to degrade thermo-labile compounds. This review covers several methods for retaining and enhancing the phenolic content of cereals to develop functional foods. These include using bioprocesses such as germination, enzymatic, and fermentation treatments designed to enhance the phenolics in cereals. In addition, physical processes like extrusion, nixtamalization, and parboiling are discussed to improve the bioavailability of phenolics. Recent technologies utilizing ultrasound, micro- or nano-capsule polymers, and infrared utilizing processes are also evaluated for their effectiveness in improving the phenolics content and bio-accessibility. We also present contemporary products made from pigmented cereals that contain phenolics.

Transcriptomics Integrated With Widely Targeted Metabolomics Reveals the Mechanism Underlying Grain Color Formation in Wheat at the Grain-Filling Stage

Colored wheat grains have a unique nutritional value. To elucidate the color formation mechanism in wheat seeds, comprehensive metabolomic and transcriptomic analyses were conducted on purple (Dianmai 20-1), blue (Dianmai 20-8), and white (Dianmai 16) wheat at the grain-filling stage. The results showed that the flavonoid biosynthesis pathway was closely related to grain color formation. Among the 603 metabolites identified in all varieties, there were 98 flavonoids. Forty-six flavonoids were detected in purple and blue wheat, and there were fewer flavonoids in white wheat than in colored wheat. Integrated transcriptomic and metabolomic analyses showed that gene expression modulated the flavonoid composition and content, resulting in different metabolite levels of pelargonidin, cyanidin, and delphinidin, thus affecting the color formation of wheat grains. The present study clarifies the mechanism by which pigmentation develops in wheat grains and provides an empirical reference for colored wheat breeding.

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.

Exploring the genic resources underlying metabolites through mGWAS and mQTL in wheat: From large-scale gene identification and pathway elucidation to crop improvement

Common wheat (Triticum aestivum L.) is a leading cereal crop, but has lagged behind with respect to the interpretation of the molecular mechanisms of phenotypes compared with other major cereal crops such as rice and maize. The recently available genome sequence of wheat affords the pre-requisite information for efficiently exploiting the potential molecular resources for decoding the genetic architecture of complex traits and identifying valuable breeding targets. Meanwhile, the successful application of metabolomics as an emergent large-scale profiling methodology in several species has demonstrated this approach to be accessible for reaching the above goals. One such productive avenue is combining metabolomics approaches with genetic designs. However, this trial is not as widespread as that for sequencing technologies, especially when the acquisition, understanding, and application of metabolic approaches in wheat populations remain more difficult and even arguably underutilized. In this review, we briefly introduce the techniques used in the acquisition of metabolomics data and their utility in large-scale identification of functional candidate genes. Considerable progress has been made in delivering improved varieties, suggesting that the inclusion of information concerning these metabolites and genes and metabolic pathways enables a more explicit understanding of phenotypic traits and, as such, this procedure could serve as an -omics-informed roadmap for executing similar improvement strategies in wheat and other species.

Insight into the pigmented anthocyanins and the major potential co-pigmented flavonoids in purple-coloured leaf teas

Tea cultivars possessing purple shoots have attracted global interest. In order to gain a better understanding of the major chemical constituents responsible for the purple colouration, we applied widely targeted metabolomics to investigate the pigmented flavonoids of freeze-dried purple-coloured tea leaves (PTLs) in comparison with green-coloured tea leaves (GTLs). Thirty-three anthocyanins were identified, and delphinidin 3-O-galactoside and cyanidin 3-O-galactoside were found to be the most abundant in PTLs. A total of 226 metabolites including 193 flavonoids and 33 tannins were identified, and the methylated, acylated, and glycosylated flavonoids differed significantly between PTLs and GTLs. Moreover, significant differences (p < 0.01) in the average anthocyanin, flavonoid, chlorophyll and catechin contents were also observed. Four PTLs were found to contain high levels of (-)-epigallocatechin-3-(3″-O-methyl) gallate (>10 mg/g). These results suggest that structurally modified anthocyanins and major potential co-pigmented flavonoids are the chemicals primarily responsible for the purple colouration of the tea leaves.