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Mother Nature is an indispensable source of bioactive natural products. Bioactive secondary metabolites have played a crucial role in the drug development and discovery process; mainly, anticancer and antibiotic molecules are extensively enriched with molecules of natural origin. Anthocyanins are water-soluble secondary metabolites found in most species in the plant domain, especially flowers, fruits, and tubers. These natural vacuolar pigments belong to the chemical class of phenolic moieties, which are responsible for the shiny orange, red, blue, pink, and violet colors in the fruits, flowers, and vegetables. Chemically, anthocyanins comprise a core structure in the form of flavylium cation or 2-phenylbenzopyrylium, and these natural colorants are polyhydroxy and polymethoxy analouges of this flavylium cation and can have sugar moieties or acylated groups linked at different positions. Currently, these molecules have raised a growing interest because of their wide range of colors, innocuous and beneficial health effects, and commercial application in functional foods, nutraceuticals, pharmaceutical and cosmetic industries. However, interest in anthocyanin derivatives has noticeably enhanced in recent years due to their higher stability, improved bioavailability in biological matrices, and better use in food matrices and cosmetic products. Due to the enormous potential of natural anthocyanins and their derivatives, this review tries to cover syntheses of anthocyanins and their analogues, chemical derivatization of anthocyanins, and anticancer activities, such as breast, colorectal, leukemia, lung, prostate, and skin cancer of anthocyanins efficiently.

The present review has analyzed the scientific literature, available in the PubMed and Scopus databases, in order to summarize the current state of diet anthocyanin research in breast cancer (BC) and colorectal cancer (CRC) animal models but also for up-to-date human studies. For CRC, 28 preclinical and 9 clinical studies were selected in line with our search query in science databases. In relation to BC, 14 preclinical and 5 clinical studies were selected. Remarkably, all the preclinical studies, to a greater or lesser degree, suggested a chemoprevention effect of anthocyanin in BC/CRC rodent models. These encouraging results from animal models are not extrapolated to the same degree to human studies where, from the similar theoretical daily doses of anthocyanins in these studies, the opposite results were reported. Nevertheless, it is worth mentioning that the anthocyanin doses in the human studies carried out recently are low if we consider the estimated exposure to anthocyanins issued by the European Food Safety Agency (EFSA) or extremely low if we consider with caution the human equivalent dose based on body surface area from the preclinical dosage regimes used. Therefore, although some clinical data has demonstrated an inverse relation between anthocyanin consumption and BC/CRC, this could, in fact, be more relevant if we increase the daily human anthocyanin dose (as observed in animal model dose-effect studies) while new toxicological data for this flavonoid subtype are brought to light.

The key regulatory gene CaAN2 encodes an R2R3 MYB transcription factor that regulates anthocyanin biosynthesis in various tissues in pepper ( Capsicum annuum ). However, CaAN2 is not expressed in certain pepper accessions showing fruit-specific anthocyanin accumulation. In this study, we identified the novel locus CaAN3 as a regulator of fruit-specific anthocyanin biosynthesis, using an F 2 population derived from a hybrid cultivar with purple immature fruits and segregating for CaAN3 . We extracted total RNA, assembled two RNA pools according to fruit color, and carried out bulked segregant RNA sequencing. We aligned the raw reads to the pepper reference genome Dempsey and identified 6,672 significant single nucleotide polymorphisms (SNPs) by calculating the Δ(SNP-index) between the two pools. We then conducted molecular mapping to delimit the target region of CaAN3 to the interval 184.6–186.4 Mbp on chromosome 10. We focused on Dem.v1.00043895, encoding an R2R3 MYB transcription factor, as the strongest candidate gene. Sequence analysis revealed four insertion/deletion polymorphisms in the promoter region of the green CaAN3 allele. We employed virus-induced gene silencing and transient overexpression assays to characterize the function of the candidate gene. When Dem.v1.00043895 was silenced in pepper, anthocyanin accumulation decreased in the pericarp, while the transient overexpression of Dem.v1.00043895 in Nicotiana benthamiana leaves resulted in the accumulation of anthocyanins around the infiltration sites. These results showed that Dem.v1.00043895 is CaAN3 , an activator of anthocyanin biosynthesis in pepper fruits.

Increasing ultraviolet (UV) radiation is causing oxidative stress that accounts for growth and yield losses in the present era of climate change. Plant hormones are useful tools for minimizing UV-induced oxidative stress in plants, but their putative roles in protecting tomato development under UVC remain unknown. Therefore, we investigated the underlying mechanism of pre-and post-kinetin (Kn) treatments on tomato plants under UVC stress. The best dose of Kn was screened in the preliminary experiments, and this dose was tested in further experiments. UVC significantly decreases growth traits, photosynthetic pigments, protein content, and primary metabolites (proteins, carbohydrates, amino acids) but increases oxidative stress biomarkers (lipid peroxidation, lipoxygenase activity, superoxide anion, hydroxyl radical, and hydrogen peroxide) and proline content. Treatment of pre-and post-kinetin spraying to tomato plants decreases UVC-induced oxidative stress by restoring the primary and secondary metabolites’ (phenolic compounds, flavonoids, and anthocyanins) status and upregulating the antioxidant defense systems (non-enzymatic antioxidants as ascorbate, reduced glutathione, α-tocopherol as well as enzymatic antioxidants as superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione-S-transferase, and phenylalanine ammonia-lyase). Thus, the application of Kn in optimum doses and through different modes can be used to alleviate UVC-induced negative impacts in tomato plants. Graphical abstract

Anthocyanin accumulation is a hallmark response to nitrogen (N) deficiency in Arabidopsis. Although the regulation of anthocyanin biosynthesis has been extensively studied, the roles of chromatin modification in this process are largely unknown. In this study we show that anthocyanin accumulation induced by N deficiency is modulated by HISTONE DEACETYLASE15 (HDA15) in Arabidopsis seedlings. The hda15-1 T-DNA insertion mutant accumulated more anthocyanins than the wild-type when the N supply was limited, and this was caused by up-regulation of anthocyanin biosynthetic and regulatory genes in the mutant. The up-regulated genes also had increased levels of histone acetylation in the mutant. The accumulation of anthocyanins induced by sucrose and methyl jasmonate, but not that induced by H2O2 and phosphate starvation, was also greater in the hda15-1 mutant. While sucrose increased histone acetylation in the hda15-1 mutant in genes in a similar manner to that caused by N deficiency, methyl jasmonate only enhanced histone acetylation in the genes involved in anthocyanin biosynthesis. Our results suggest that different stresses act through distinct regulatory modules to activate anthocyanin biosynthesis, and that HDA15-mediated histone modification modulates the expression of anthocyanin biosynthetic and regulatory genes to avoid overaccumulation in response to N deficiency and other stresses.

As apple fruits (Malus domestica) mature, they accumulate anthocyanins concomitantly with losing chlorophyll (Chl); however, the molecular pathways and events that coordinate Chl degradation and fruit coloration have not been elucidated. We showed previously that the transcription factor ETHYLENE RESPONSE FACTOR17 (MdERF17) modulates Chl degradation in apple fruit peels and that variation in the pattern of MdERF17 serine (Ser) residues is responsible for differences in its transcriptional regulatory activity. Here, we report that MdERF17 interacts with and is phosphorylated by MAP KINASE4 (MdMPK4-14G). Phosphorylation of MdERF17 at residue Thr67 by MdMPK4-14G is necessary for its transcriptional regulatory activity and its regulation of Chl degradation. We also show that MdERF17 mutants with different numbers of Ser repeat insertions exhibit altered phosphorylation profiles, with more repeats increasing its interaction with MdMPK4. MdMPK4-14G can be activated by exposure to darkness and is involved in the dark-induced degreening of fruit peels. We also demonstrate that greater phosphorylation of MdERF17 by MdMPK4-14G is responsible for the regulation of Chl degradation during light/dark transitions. Overall, our findings reveal the mechanism by which MdMPK4 controls fruit peel coloration.

Anthocyanin production in apple (Malus domestica) fruit and their consequent coloration can be induced by high-light treatment. The hormone ethylene is also essential for this coloration, but the regulatory relationships that link ethylene and light with anthocyanin-associated coloration are not well defined. In this study, we observed that high-light treatment of apple fruit increased anthocyanin accumulation more than moderate-light treatment did and was the main contributor of induced ethylene production and activation of anthocyanin biosynthesis. A transcriptome study of light-treated apple fruit suggested that a long noncoding RNA (lncRNA), MdLNC610, the corresponding gene of which is physically located downstream from the 1-aminocyclopropane-1-carboxylate oxygenase (ACO) ethylene biosynthesis gene MdACO1, likely affects anthocyanin biosynthesis under high-light treatment. Expression and promoter β-glucuronidase reporter analyses further showed that MdLNC610 upregulates expression of MdACO1 and so likely participates in high-light-induced ethylene biosynthesis. Overexpression of MdACO1 and MdLNC610 in apple fruit and calli indicated that a major increase in MdLNC610 expression activates MdACO1 expression, thereby causing an increase in ethylene production and anthocyanin levels. These results suggest that MdLNC610 participates in the regulation of high-light-induced anthocyanin production by functioning as a positive regulator to promote MdACO1 expression and ethylene biosynthesis. Our study provides insights into the relationship between mRNA and lncRNA networks in the ethylene biosynthetic pathway and anthocyanin accumulation in apple fruit.

Anthocyanins are a group of phytochemicals responsible for the purple or red color of plants. Additionally, they are recognized to have health promoting functions including anti-cardiovascular, anti-thrombotic, anti-diabetic, antimicrobial, neuroprotective, and visual protective effect as well as anti-cancer activities. Thus, consumption of anthocyanin supplement or anthocyanin-rich foods has been recommended to prevent the risk of development of chronic diseases. However, the low stability and bioavailability of anthocyanins limit the efficacy and distribution of anthocyanins in human body. Thus, strategies to achieve target site-local delivery with good bioavailability and controlled release rate are necessary. This review introduced and discussed the latest advanced techniques of designing lipid-based, polysaccharide-based and protein-based complexes, nano-encapsulation and exosome to overcome the limitation of anthocyanins. The improved bioavailability and controlled release of anthocyanins have great significance for gastrointestinal tract absorption, transepithelial transportation and cellular uptake. The techniques of applying different biocompatible materials and modifying the solubility of anthocyanins complex could achieve target site-local delivery with negligible degradation and good bioavailability in human body.

Background Fruits are vital food resources as they are loaded with bioactive compounds varying with different stages of ripening. As the fruit ripens, a dynamic color change is observed from green to yellow to red due to the biosynthesis of pigments like chlorophyll, carotenoids, and anthocyanins. Apart from making the fruit attractive and being a visual indicator of the ripening status, pigments add value to a ripened fruit by making them a source of nutraceuticals and industrial products. As the fruit matures, it undergoes biochemical changes which alter the pigment composition of fruits. Results The synthesis, degradation and retention pathways of fruit pigments are mediated by hormonal, genetic, and environmental factors. Manipulation of the underlying regulatory mechanisms during fruit ripening suggests ways to enhance the desired pigments in fruits by biotechnological interventions. Here we report, in-depth insight into the dynamics of a pigment change in ripening and the regulatory mechanisms in action. Conclusions This review emphasizes the role of pigments as an asset to a ripened fruit as they augment the nutritive value, antioxidant levels and the net carbon gain of fruits; pigments are a source for fruit biofortification have tremendous industrial value along with being a tool to predict the harvest. This report will be of great utility to the harvesters, traders, consumers, and natural product divisions to extract the leading nutraceutical and industrial potential of preferred pigments biosynthesized at different fruit ripening stages.

Consumption of high fat diets (HFD) and the associated metabolic endotoxemia can initiate liver inflammation and lipid deposition that with time can progress to non-alcoholic fatty liver disease (NAFLD). We previously observed that 14 weeks supplementation with the anthocyanidins cyanidin and delphinidin mitigated HFD-induced metabolic endotoxemia and liver insulin resistance, steatosis, inflammation and oxidative stress. This work investigated if a 4-week supplementation of mice with a cyanidin- and delphinidin-rich extract (CDRE) could mitigate or reverse HFD (60% calories from lard fat)-induced liver steatosis and inflammation. After a first 4-weeks period on the HFD, mice showed increased endotoxemia and activation of liver proinflammatory signaling cascades. Supplementation with CDRE between weeks 4 and 8 did not mitigate liver steatosis or the altered lipid and glucose plasma levels. However, CDRE supplementation reverted HFD-induced metabolic endotoxemia, in parallel with the mitigation of the overexpression of hepatic TLR2 and TLR4, and of the activation of: (i) NF-κB, (ii) AP-1 and upstream mitogen-activated kinases p38 and ERK1/2, and (iii) HIF-1. Thus, even a short-term consumption of cyanidin and delphinidin could help mitigate the adverse consequences

Objective: Asthma, caused by chronic inflammation, is a common disease. Anthocyanins are involved in asthma treatment. This study explored the mechanism of anthocyanins on airway inflammation in asthmatic mice by regulating nuclear factor-κB (NF-κB) via the miR-138-5p/sirtuin-1 (SIRT1) axis. Methods: The asthmatic mouse model was established by ovalbumin (OVA) induction and treated with anthocyanins or simultaneously injected with the lentivirus miR-138-5p mimic, followed by the measurement of lung inflammatory injury and IL-4, IL-5, IL-13, and IFN-γ levels in bronchoalveolar lavage fluid. Human bronchial epithelial (HBE) cells 16HBE14o-160 were induced by OVA to establish an asthmatic cell model, treated with anthocyanins and manipulated with miR-138-5p mimic and pcDNA3.1-SIRT1. The releases of inflammatory cytokines, the nuclear translocation of p-p65/p65 in the NF-κB pathway, and the levels of miR-138-5p and SIRT1 mRNA were detected. Results: In vivo experiments showed that anthocyanins could reduce the OVA-induced airway hyperresponsiveness and airway inflammation, improve the inflammatory infiltration and mucus in lung tissues, and diminish the miR-138-5p level in asthmatic mice. Infection with the miR-138-5p mimic averted the remission effect of anthocyanins in asthmatic mice. In vitro experiments showed that in HBE cells exposed to OVA, anthocyanins reduced the miR-138-5p level, increased the SIRT1 level, inhibited the release of inflammatory factors, and reduced the nuclear translocation of NF-κB p65. miR-138-5p targeted SIRT1. miR-138-5p overexpression partially reversed the therapeutic effect of anthocyanins, while SIRT1 overexpression antagonized the effect of miR-138-5p overexpression. Conclusion: Anthocyanins inhibited the NF-κB pathway by regulating the miR-138-5p/SIRT1 axis, thus inhibiting airway inflammation in asthmatic mice.

Anthocyanins, a class of flavonoid compounds that provide pigmentation to plant organs, are beneficial components of the human diet and there is an interest in understanding the regulation of their formation in crop plants. The apple cultivar ‘May’ represents an excellent model for the study of anthocyanin metabolism due to the spatial color pattern of its flesh, which transitions sequentially from red to white to red again, from the outside to the inside of the apple fruit. To screen the transcription factors involved in the anthocyanin pathway, transcriptomes from differently colored sections of ‘May’ fruits were analyzed by RNA sequencing. Kyoto Encyclopedia of Genes and Genomes (KEGG) database was used to analyse the gene expression data. The results suggested differentially expressed genes (DEGs) that are related to phytohormones are involved in regulating anthocyanin biosynthesis. K-means clustering analysis revealed 167 common DEGs between different sections of fruit with the same expression pattern as candidates for regulating anthocyanin synthesis. Further analysis showed that nine of the 167 DEGs were annotated as transcription factors and quantitative real time PCR (qRT-PCR) confirmed that their expression was obviously higher in red regions of the fruit, consistent with their roles as hub genes that regulate anthocyanin synthesis. This study provides valuable results for future studies of anthocyanin synthesis in apple fruit.

Genome-wide transcriptome analysis provides systems-level insights into plant biology. Due to the limited depth of quantitative proteomics our understanding of gene-protein-complex stoichiometry is largely unknown in plants. Recently, the complexity of the proteome and its cell-/tissue-specific distribution have boosted the research community to the integration of transcriptomics and proteomics landscapes in a proteogenomic approach. Herein, we generated a quantitative proteome and transcriptome abundance atlas of 15 major sweet cherry (Prunus avium L., cv 'Tragana Edessis') tissues represented by 29 247 genes and 7584 proteins. Additionally, 199 984 alternative splicing events, particularly exon skipping and alternative 3' splicing, were identified in 23 383 transcribed regions of the analyzed tissues. Common signatures as well as differences between mRNA and protein quantities, including genes encoding transcription factors and allergens, within and across the different tissues are reported. Using our integrated dataset, we identified key putative regulators of fruit development, notably genes involved in the biosynthesis of anthocyanins and flavonoids. We also provide proteogenomic-based evidence for the involvement of ethylene signaling and pectin degradation in cherry fruit ripening. Moreover, clusters of genes and proteins with similar and different expression and suppression trends across diverse tissues and developmental stages revealed a relatively low RNA abundance-to-protein correlation. The present proteogenomic analysis allows us to identify 17 novel sweet cherry proteins without prior protein-level annotation evidenced in the currently available databases. To facilitate use by the community, we also developed the Sweet Cherry Atlas Database (https://grcherrydb.com/) for viewing and data mining these resources. This work provides new insights into the proteogenomics workflow in plants and a rich knowledge resource for future investigation of gene and protein functions in Prunus species.

BACKGROUND During winemaking, after extraction from the skins, anthocyanins and tannins adsorb onto the pulp flesh cell walls. This study aims to quantify the amounts adsorbed and their impact on wine composition, the impact of variety and ethanol on adsorption, and whether the presence of anthocyanins plays a role and impacts tannin adsorption. RESULTS Anthocyanin and tannin fractions obtained by mimicking winemaking conditions were mixed with fresh flesh cell walls of two varieties: Carignan and Grenache. Adsorption isotherms were measured. Adsorption of tannins was higher with Carignan than with Grenache and decreased when the ethanol content increased. In comparison, anthocyanins were adsorbed in small amounts, and their mixing with tannins had no impact on their adsorption. The differences were related to differences in pulp cell wall composition, particularly in terms of extensins and arabinans. CONCLUSION Adsorption of tannins, which can reach 50% of the initial amount, depends on the pulp cell wall composition. This needs to be further investigated. This article is protected by copyright. All rights reserved.

Red wines are characterized by their astringency, a very important sensory attribute that affects the perceived quality of wines. Three mechanisms have been proposed to explain astringency, and two theories describe how these mechanisms work in an integrated manner to produce tactile sensations such as drying, roughening, shrinking and puckering. The factors involved include not only tannins and salivary proteins, but also anthocyanins, grape polysaccharides and mannoproteins, as well as other wine matrix components that modulate their interactions. These multifactorial interactions could be responsible for different sensory responses and therefore need to be further studied. This review presents the latest advances in astringency perception and its possible origins, with special attention on the interactions of components, their impact on oral perception and the development of astringency sub-qualities. Future research efforts should concentrate on understanding the mechanisms involved as well as on the limiting factors related to the conformation and stability of the tannin - salivary protein complexes. This article is protected by copyright. All rights reserved.

Reactive species (RS) causing oxidative stress are unavoidable by-products of various plant metabolic processes, such as photosynthesis, respiration or photorespiration. In leaves, flavonoids scavenge RS produced during photosynthesis and protect plant cells against deleterious oxidative damages. Their biosynthesis and accumulation are therefore under tight regulation at the cellular level. Glycosylation has emerged as an essential biochemical reaction in the homeostasis of various specialized metabolites such as flavonoids. This article provides a functional characterization of the Populus tremula x P. alba (poplar) UGT72A2 coding for a UDP-glycosyltransferase that is localized in the chloroplasts. Compared with the wild type, transgenic poplar lines with decreased expression of UGT72A2 are characterized by reduced growth and oxidative damages in leaves, as evidenced by necrosis, higher content of glutathione and lipid peroxidation products as well as diminished soluble peroxidase activity and NADPH to NADP+ ratio under standard growing conditions. They furthermore display lower pools of phenolics, anthocyanins and total flavonoids but higher proanthocyanidins content. Promoter analysis revealed the presence of cis-elements involved in photomorphogenesis, chloroplast biogenesis and flavonoid biosynthesis. The UGT72A2 is regulated by the poplar MYB119, a transcription factor known to regulate the flavonoid biosynthesis pathway. Phylogenetic analysis and molecular docking suggest that UGT72A2 could glycosylate flavonoids; however, the actual substrate(s) was not consistently evidenced with either in vitro assays nor analyses of glycosylated products in leaves of transgenic poplar overexpressing or downregulated for UGT72A2. This article provides elements highlighting the importance of flavonoid glycosylation regarding protection against oxidative stress in poplar leaves and raises new questions about the link between this biochemical reaction and regulation of the redox homeostasis system.

Rhododendron delavayi is a popular ornamental plant with globular flowers noted for their bright red color, but very limited studies have been reported on its flower color formation. In this study, we successfully isolated a novel DFR gene (RdDFR1) from red flowers of Rhododendron delavayi. Multiple sequence alignments revealed that RdDFR1 had the conserved NADP and substrate binding domain, and was classified into Asn-type DFR. Meanwhile, quantitative real-time PCR analysis showed that transcript levels of RdDFR1 matched the accumulation patterns of anthocyanins during flower development, hinting its potential role involved in anthocyanin biosynthesis. Then in vitro enzymatic analysis indicated that recombinant RdDFR1 protein could catalyze the production of leucoanthocyanidins from dihydroquercetin and dihydromyricetin. Furthermore, the in planta assay, using Arabidopsis thaliana dfr mutant (tt3-1) and tobacco, displayed that RdDFR1 transgenes recovered the defective proanthocyanidin and anthocyanin biosynthesis at seed coats, hypocotyl as well as cotyledon, and altered the flowers color of tobacco from pale pink to dark pink which demonstrated its function as dihydroflavonol 4-reductase in vivo. In summary, our findings suggest that RdDFR1 plays a crucial role in the biosynthesis of anthocyanin and will also make a contribution to understand the mechanisms of flower color formation in Rhododendron delavayi.

The final concentration of phenolic compounds in wines is usually lower than what might be expected, given their concentration in grapes. This is in part due to the interactions between cell walls from grapes and yeast with phenolics during red winemaking. Most of these aggregates are insoluble and end up precipitating, forming part of the lees. The objective of this study is to determine the capacity of ultrasounds and/or enzymes treatments (β-glucanase and a pectolytic enzyme) to release the anthocyanins and tannins adsorbed in the lees. The ultrasound (US) applied for 120 min slightly favored the extraction of anthocyanins and doubled tannin extraction. Shorter sonication times did not show any positive effect. The combination of β-glucanase and pectolytic enzyme was always more effective in the liberation of anthocyanins (both no-acylated and acylated anthocyanins) and tannins than the enzymes acting separately. The combination of US (120 min), β-glucanase and pectolytic enzyme showed an additive effect, increasing the extraction of phenolic compounds with respect to the individual treatments and also releasing a large quantity of low molecular weight polysaccharides, compounds of enological importance. These results of this study could be of enological interest, facilitating and accelerating the aging on lees process, through the liberation of polysaccharides and the recovery of the phenolic compounds lost during vinification.

Anthocyanins have been shown to exert certain antiobesity properties, but the specific relationship between anthocyanin-induced beneficial effects and the gut microbiota remains unclear. Petunidin-3-O-[rhamnopyranosyl-(trans-p-coumaroyl)]-5-O-(β-D-glucopyranoside) (P3G) is the main anthocyanin monomer from the fruit of Lycium ruthenicum Murray. Therefore, in this study, we investigated the antiobesity and remodeling effects of P3G on gut microbiota through a high-fat diet (HFD)-induced obesity mouse model and a fecal microbiota transplantation experiment. P3G was found to reduce body weight gain, fat accumulation, and liver steatosis in HFD-induced obese mice. Moreover, supplementation with P3G alleviated the HFD-induced imbalance in gut microbiota composition, and transferring the P3G-regulated gut microbiota to recipient mice provided comparable protection against obesity. This is the first time evidence is provided that P3G has an antiobesity effect by changing the intestinal microbiota. Our present data highlight a link between P3G intervention and enhancement in gut barrier integrity. This may be a promising option for obesity prevention.

Water-in-oil-in-water (W1/O/W2) emulsions (double emulsions) have often been used for the encapsulation of bioactive compounds such as anthocyanins. Instability of both anthocyanins and double emulsions creates a need for a tailored composition of the aqueous phase. In this work, double emulsions with a gelled internal water phase were produced and monitored over a 20-day storage period. The effect of the electrolyte phase composition (varying electrolyte components, including adipic acid, citric acid, and varying concentration of potassium chloride (KCl)) on anthocyanin and double emulsion stability was analysed using colour analysis, droplet sizing, and emulsion rheology. The effect of electrolytes on colour retention was shown to differ between the primary W1/O emulsion and the secondary W1/O/W2 emulsion. Furthermore, droplet size analysis and emulsion rheology highlighted significant differences in the stability and structural behaviour of the emulsions as a function of electrolyte composition. In terms of colour retention and emulsion stability, a citrate-buffered system performed best. The results of this study highlight the importance of strict control of aqueous phase constituents to prevent anthocyanin degradation and maximise double emulsion stability. Additional experiments analysed the effect of pectin chemistry on the anthocyanin colour retention and leakage, finding no conclusive difference between the unmodified and amidated pectin.

BACKGROUND During the storage and processing of Lilium bulbs, the phenomenon of violet-red colour change in Lilium bulbs which is different from enzymatic browning often exists, but the specific mechanism is not clear. RESULTS In this study, we chose six-year-old Lilium davidii var. unicolor to study. Bulb scales which were sealed in polyethylene film plastic bags were exposed to room temperature (20 ± 2 °C) treatment for 5 days (12 h of sunshine and 12 h of sun shading). Metabolomics and transcript omics were conducted to elucidate the mechanism of violet-red color change in Lilium bulbs. The results showed that the color of Lilium bulb scales was obvious violet-red in 5 days; chromaticity value measuring showed the a values had the most significant upward trend. Metabolomics analysis showed many metabolites produced from the flavonoid biosynthesis pathway showed an upward trend. Transcriptome revealed that flavonoid biosynthesis pathway was significantly enriched, of which 20 synthesis genes were highly regulated expression. Metabolome and transcriptome co-analysis that up-regulated expression of flavonoids synthesis genes including ten chalcone synthase, two anthocyanidin reductase, and chalcone isomerase, 3'-hydroxylase, 3-hydroxylase, dihydroflavonol 4-reductase, anthocyanin synthase, anthocyanidin 3-O-glucosyltransferase and flavonol synthase were highly positive correlated with epicatechin, rutin and cyanidin 3-rutinoside. CONCLUSION Phenotypic, metabolomic and transcriptomic analysis indicated that the up-related expression levels of genes and accumulated flavonoids related to flavonoid metabolism contributed greatly to the violet-red colour change in Lilium bulbs. The results of this study will deepen our understanding of the color formation of violet-red Lilium bulbs and provide the basis for future storage and preservation of Lilium bulbs. © 2021 Society of Chemical Industry.

14 Pág. Departamento de Tecnología de Alimentos​​, Background: Anthocyanins are a major class of plant phenolic pigments, responsible for the red, purple or blue color of leaves, flowers, tubers, fruits and certain vegetables. They are considered the largest and most important group of water-soluble pigments in nature and have been described to have multiple health-promoting properties. However, the bioavailability of anthocyanins is reportedly extremely low, affected by factors inherent to the molecule's characteristics, as well as by the effect of food processing, transformations during the digestive process and their levels in fruits. Scope and approach: This review aims to discuss current knowledge regarding the effects of technological processes used in the food industry on the stability, bioavailability and biological effect of anthocyanins. In addition, a review of new trends in the improvement of anthocyanin production in plants is presented, which outlines what has been reported about genes involved in the regulation and its expression. Key findings and conclusions: The alterations that anthocyanins suffer, which can affect their bioavailability and biological effects, do not take place solely during the digestion process, caused mainly by pH and intrinsic and bacterial enzymes, but also during the different processing methods that food-containing anthocyanins can undergo. Factors such as thermal and non-thermal processing, storage, oxidative degradation and encapsulation systems have been shown to closely influence anthocyanins' stability and biological effects. In recent times, genetic manipulation aiming at upregulating the gene expression of metabolic pathways has been used to improve fruit quality and anthocyanin content in plant foods, and may also contribute towards counteracting some of the indicated limitations., This work was supported by the Universidad de Las Américas (UDLA) (grant number AGR.JMA.20.05). The GIP-USAL is grateful to the Spanish Government for the funding received through the grants with reference nos. AGL2015-64522-C2 and PDI2019-106167RB-100. The authors also would like to thank Ms Helen Pugh for her extensive proof-reading of the manuscript.

Background Anthocyanins, which belong to flavonoids, are widely colored among red-purple pigments in the Asiatic hybrid lilies (Lilium spp.). Transcription factor (TF) LhMYBSPLATTER (formerly known as LhMYB12-Lat), identified as the major kernel protein, regulating the anthocyanin biosynthesis pathway in ‘Tiny Padhye’ of Tango Series cultivars, which the pigmentation density is high in the lower half of tepals and this patterning is of exceptional ornamental value. However, the research on mechanism of regulating the spatial and temporal expression differences of LhMYBSPLATTER, which belongs to the R2R3-MYB subfamily, is still not well established. To explore the molecular mechanism of directly related regulatory proteins of LhMYBSPLATTER in the anthocyanin pigmentation, the yeast one-hybrid (Y1H) cDNA library was constructed and characterized. Results In this study, we describe a yeast one-hybrid library to screen transcription factors that regulate LhMYBSPLATTER gene expression in Lilium, with the library recombinant efficiency of over 98%. The lengths of inserted fragments ranged from 400 to 2000 bp, and the library capacity reached 1.6 × 106 CFU of cDNA insert, which is suitable to fulfill subsequent screening. Finally, seven prey proteins, including BTF3, MYB4, IAA6-like, ERF4, ARR1, ERF WIN1-like, and ERF061 were screened by the recombinant bait plasmid and verified by interaction with the LhMYBSPLATTER promoter. Among them, ERFs, AUX/IAA, and BTF3 may participate in the negative regulation of the anthocyanin biosynthesis pathway in Lilium. Conclusion A yeast one-hybrid library of lily was successfully constructed in the tepals for the first time. Seven candidate TFs of LhMYBSPLATTER were screened, which may provide a theoretical basis for the study of floral pigmentation.

Background Higher flavonoid intakes are hypothesised to confer protection against type 2 diabetes mellitus. Objective We aimed to 1) investigate associations between flavonoid intakes and diabetes, 2) examine the mediating impact of body fat, and 3) identify subpopulations that may receive the greatest benefit from higher flavonoid intakes in participants of the Danish Diet, Cancer, and Health Study followed-up for 23 years. Design Cross-sectional associations between baseline flavonoid intake, estimated using food frequency questionnaires and the Phenol Explorer database, and body fat estimated by bioelectrical impedance, were assessed using multivariable-adjusted linear regression models. Non-linear associations between flavonoid intake and incident diabetes were examined using restricted cubic splines with multivariable-adjusted Cox proportional hazards models. Results Among 54,787 participants (median [IQR] age of 56 [52-60] years; (47.3%) men), 6700 individuals were diagnosed with diabetes. Participants in the highest total flavonoid intake quintile (median, 1,202 mg/d) had a 1.52 kg lower body fat (95%CI: -1.74, -1.30) and a 19% lower risk of diabetes [hazard ratio (95%CI): 0.81 (0.75, 0.87)] after multivariable adjustments and compared to participants in the lowest intake quintile (median, 174 mg/d). Body fat mediated 57% (95% CI: 42%, 83%) of the association between flavonoid intake and incident diabetes. Of the flavonoid subclasses, moderate to high intakes of flavonols, flavanol monomers, flavanol oligo + polymers, and anthocyanins were significantly associated with a lower risk of diabetes. While associations were not modified by sex, smoking status, BMI or physical activity (pinteraction > 0.05 for all), findings on an absolute scale suggest that those at a higher risk (those with obesity) may benefit the most from a higher flavonoid intake. Conclusions These findings suggest that a diet abundant in flavonoid-rich foods may help to ameliorate diabetes risk, in part through a reduction in body fat.

An R2R3-MYB transcription factor, CmMYB9a, activates floral coloration in chrysanthemum by positively regulating CmCHS, CmDFR and CmFNS, but inhibiting the expression of CmFLS. Chrysanthemum is one of the most popular ornamental plants worldwide. Flavonoids, such as anthocyanins, flavones, and flavonols, are important secondary metabolites for coloration and are involved in many biological processes in plants, like petunia, snapdragon, Gerbera hybrida, as well as chrysanthemum. However, the metabolic regulation of flavonoids contributing to chrysanthemum floral coloration remains largely unexplored. Here, an R2R3-MYB transcription factor, CmMYB9a, was found to be involved in flavonoid biosynthesis. Phylogenetic analysis and amino acid sequence analysis suggested that CmMYB9a belonged to subgroup 7. Transient overexpression of CmMYB9a in flowers of chrysanthemum cultivar 'Anastasia Pink' upregulated the anthocyanin-related and flavone-related genes and downregulated CmFLS, which led to the accumulation of anthocyanins and flavones. We further demonstrated that CmMYB9a independently activates the expression of CmCHS, CmDFR and CmFNS, but inhibits the expression of CmFLS. Overexpression of CmMYB9a in tobacco resulted in increased anthocyanins and decreased flavonols in the petals by upregulating NtDFR and downregulating NtFLS. These results suggest that CmMYB9a facilitates metabolic flux into anthocyanin and flavone biosynthesis. Taken together, this study functionally characterizes the role of CmMYB9a in regulating the branched pathways of flavonoids in chrysanthemum flowers.

BACKGROUND Solanum tuberosum tubers have higher content of phenolic compounds such as hydroxycinnamic acid derivatives (HCAD) and anthocyanins in coloured genotypes. The use of fungicides for crops is common, but there are few studies regarding the interaction of fungicides and arbuscular mycorrhizal fungi (AMF). Here, the AMF-plant interactions and the metabolic responses of three potato genotypes with different tuber colorations (VR808, CB2011-509 and CB2011-104) inoculated with Claroideoglomus claroideum (CC), Claroideoglomus lamellosum (HMC26) or Funneliformis mosseae (HMC7) were studied together with the use of the fungicides MONCUT (M) and ReflectXtra (R). Mycorrhizal traits, phenolic compound profiles and antioxidant activity (AA) were evaluated. RESULTS Despite only two HCADs being identified, with 5-caffeolquinic acid the most abundant, four anthocyanins were detected only in purple potato genotypes. The anthocyanin and HCAD profiles, as well as AA, showed that the CB2011-104 genotype had better characteristics than the other genotypes, while VR808 and CB509 showed similar responses. The responses were dependent on the specific combinations of genotype, fungicide and the AMF strain, and generally showed better responses when colonized by AMFs. CONCLUSION The three potato genotypes had differential responses depending on the inoculated AMFs and the fungicide applied before sowing, where the optimal combinations for antioxidant response, mycorrhization degree and performance were HMC26/R for VR808, HMC7/M for CB2011-509 and HMC26/M for CB2011-104. Our results suggest the existence of functional compatibility that can be registered as beneficial effects even at the genotypic level of the host regarding a specific AMF strain. © 2021 Society of Chemical Industry.

In this study, silver nanoclusters as prooxidant biosensor were eco-friendly synthesized using chicken egg white protein without any chemical reducing agents for measuring copper(II)-induced prooxidant activities of catechin, epicatechin, epigallocatechin gallate, resveratrol, gallic acid, chlorogenic acid, and rutin. The prooxidant activities were evaluated via measuring the absorption at 450 nm wavelength of the Cu(I)-neocuproine chelate formed by extraction of protein-bound Cu(I) with neocuproine reagent. Accuracy was determined by evaluating recovery values of wine, grape and apple samples and the obtained values were between 97.2%-98.9%. Intraday precision and inter-day reproducibility experiments were studied with three different experiments in a day and three different days respectively. The obtained relative standard deviation values were 0.96% and 1.91%. The detection limit of the biosensor was found as 0.2 mu M. The total prooxidant activities of fresh apple and grape fruits, apple and grape juices, and red wine were determined and the results obtained were compared with the findings of the carbonyl assay. In this study, a cheap, easily applicable, sensitive, and reproducible biosensor was developed. It was seen that it could be used in the measurement of the prooxidant activity of different food samples and give an idea about diet, healthy life, and nutrition.

The R2R3 type MYB transcription factors participate in controlling flavonoid production in plants, including anthocyanin and proanthocyanin. Black rice with high anthocyanin content is an important candidate for understanding R2R3-MYB-based regulation of the anthocyanin biosynthesis pathway (ABP). This study was undertaken to draw the functional relationship of an R2R3-MYB protein with anthocyanin biosynthesis and oxidative stress tolerance in plants. The expression levels of the late ABP genes in the panicle stage of black rice were in good agreement with the accumulation of anthocyanin, especially cyanidin 3-glucoside. Among all MYB genes present in rice, an R2R3 type (C1) regulates anthocyanin biosynthesis and was studied further. The positive correlation between the expression of ABP genes and OsC1 along with the nuclear localization of OsC1 are in line with its possible involvement as a transcriptional regulator of ABP genes. Interestingly, OsC1 overexpressed in white rice plants triggered anthocyanin production through augmentation of the transcript level of late ABP genes. Moreover, OsC1-transformed plants exhibited a lower amount of reactive oxygen species upon exposure to oxidative stress. The increased anthocyanin content in white rice seedlings resulted in higher photosynthetic efficiency, less membrane damage and consequently lower oxidative stress. The OsC1 transcriptional regulator helps to ameliorate oxidative stresses in plants owing to its anthocyanin modulating ability.

Background Plants grown under shade are exposed to low red/far-red ratio, thereby triggering an array of altered phenotypes called shade avoidance syndrome (SAS). Shade negatively influences plant growth, leading to a reduction in agricultural productivity. Understanding of SAS is crucial for sustainable agricultural practices, especially for high-density indoor farming. Brassicaceae vegetables are widely consumed around the world and are commonly cultivated in indoor farms. However, our understanding of SAS in Brassicaceae vegetables and their genome-wide transcriptional regulatory networks are still largely unexplored. Results Shade induced common signs of SAS, including hypocotyl elongation and reduced carotenoids/anthocyanins biosynthesis, in two different Brassicaceae species: Brassica rapa (Choy Sum and Pak Choy) and Brassica oleracea (Kai Lan). Phenotype-assisted transcriptome analysis identified a set of genes induced by shade in these species, many of which were related to auxin biosynthesis and signaling [e.g. YUCCA8 (YUC8), YUC9, and INDOLE-3-ACETIC ACID INDUCIBLE (IAAs)] and other phytohormones signaling pathways including brassinosteroids and ethylene. The genes functioning in plant defense (e.g. MYB29 and JASMONATE-ZIM-DOMAIN PROTEIN 9) as well as in biosynthesis of anthocyanins and glucosinolates were repressed upon shade. Besides, each species also exhibited distinct SAS phenotypes. Shade strongly reduced primary roots and elongated petioles of B. oleracea, Kai Lan. However, these SAS phenotypes were not clearly recognized in B. rapa, Choy Sum and Pak Choy. Some auxin signaling genes (e.g. AUXIN RESPONSE FACTOR 19, IAA10, and IAA20) were specifically induced in B. oleracea, while homologs in B. rapa were not up-regulated under shade. Contrastingly, shade-exposed B. rapa vegetables triggered the ethylene signaling pathway earlier than B. oleracea, Kai Lan. Interestingly, shade induced the transcript levels of LONG HYPOCOTYL IN FAR-RED 1 (HFR1) homolog in only Pak Choy as B. rapa. As HFR1 is a key negative regulator of SAS in Arabidopsis, our finding suggests that Pak Choy HFR1 homolog may also function in conferring higher shade tolerance in this variety. Conclusions Our study shows that two Brassicaceae species not only share a conserved SAS mechanism but also exhibit distinct responses to shade, which will provide comprehensive information to develop new shade-tolerant cultivars that are suitable for high-density indoor farms.

Purple-fleshed sweetpotato (Ipomoea batatas（L.）Lam.) is rich in anthocyanins. R2R3-type MYB transcription factors（TFs）with EAR motifs inhibiting anthocyanin biosynthesis have been reported, and there is still a lack of information on how mutations in the EAR motifs of MYBs affect anthocyanin accumulation. In this study, we obtained three IbMYB44 TFs by bioinformatics. Among these TFs, IbMYB44.1, IbMYB44.3 with a complete EAR motif and IbMYB44.2 with a single amino acid mutant in the EAR motif caused an amino acid substitution from leucine to valine. RT-qPCR analysis showed that IbMYB44s was expressed at lower levels in the purple-fleshed sweetpotato than in nonpurple-fleshed sweetpotato (P 0.01). Transient expression assays showed that the inhibitory effect of IbMYB44.1/3 was stronger than IbMYB44.2 in tobacco leaves and red-skinned pears. RT-qPCR analysis further proved that IbMYB44.1/3 significantly inhibited the expression of anthocyanin biosynthesis-related genes compared with IbMYB44.2 in tobacco leaves and red-skinned pears. A dual luciferase reporter assay showed that IbMYB44s cannot directly activate the IbANS promoter, and the result was also verified by yeast one-hybrid (Y1H) experiments. Moreover, we identified the interaction of IbMYB340 with IbMYB44.1, IbMYB44.2 and IbMYB44.3 via yeast two-hybrid (Y2H) assays. Thus, IbMYB44.1/3 could interact with IbMYB340 to negatively regulate anthocyanin biosynthesis. This study enriched the regulatory network of anthocyanins and also provided a theoretical basis for a single amino acid mutant from leucine to valine in the EAR motif of IbMYB44.2 affecting anthocyanin biosynthesis in the purple-fleshed sweetpotato.

The AP2/ERF (APETALA2/Ethylene Response Factor) transcription factor superfamily plays crucial roles in a slew of physiological processes, such as plant growth and development, stress response, and secondary metabolites biosynthesis. Eggplant, especially the one rich with anthocyanins, is an economically important horticultural vegetable cultivated worldwide. In this study, we comprehensively analyzed the putative AP2/ERF gene family members and their response to abiotic stress in eggplant. As per the phylogenetic, conserved domains, and motif analysis, 178 AP2/ERF genes in this study belonged to five subfamilies. Chromosomal distributions analysis elucidated stochastic distribution of 178 putative SmAP2/ERF genes across the twelve chromosomes of eggplant. Expression profiles of sixteen selected AP2/ERF genes response to low temperature, drought, salt, abscisic acid, and ethylene treatments were analyzed, which revealed the involvement of SmAP2/ERF genes in diverse signaling pathways. In addition, we integrated RNA-Seq data on anthocyanin biosynthesis in eggplant with yeast one-hybrid and dual-luciferase assays and identified involvement of the SmAP2/ERF genes (Smechr0902114.1 and Smechr1102075.1) in the regulation of anthocyanin biosynthesis. This study will enable further functional characterization of AP2/ERF genes in eggplant and extend the current understanding of the role played by AP2/ERF genes in anthocyanin biosynthesis regulation.

Anthocyanins (ACs) are able to protect neurons against β-amyloid-induced neurotoxicity. In this study, we evaluated blood-brain barrier (BBB) permeability of these compounds using a model kit to clarify the mechanism of AC on the brain. Black currant or strawberry AC extract was orally administrated to male Wistar rats. The urine and extirpated brain were collected before and after administration and analyzed quantitatively by liquid chromatography-tandem mass spectrometry. After administration of AC, several phenolic acids were detected in the urine samples. Further, AC and some AC metabolites were found in the brain tissue. BBB permeabilities of these compounds were much lower than the positive control. Epigallocatechin, daidzein, genistein, equol, and nobiletin presented high BBB permeability, whereas apigenin, luteolin, quercetin, and kaempferol showed medium permeability, and epicatechin, rutin, fisetin, resveratrol, and curcumin BBB permeation was neglected. These results suggested that ACs were difficult to cross BBB into the brain and ACs were not directly associated with the prevention of β-amyloid-induced neurotoxicity.

The Mediterranean diet (MD) is becoming a milestone for the prevention of chronic diseases, such as cardiovascular diseases (CVDs), Alzheimer’s and Parkinson’s disease. Ancel Keys in the 1950’s showed a low mortality rate, particularly for coronary heart disease, among people resident in the Mediterranean area. The MD is characterized by the intake of the high amount of vegetables, fruit, and cereals and regular but moderate consumption of wine, fish, and dairy products, while olive oil is the main source of culinary fat. Therefore, it is principally a plant-based diet rich in polyphenols, a heterogeneous category of compounds with different properties and bioavailabilities. Among polyphenols, anthocyanins have been combined into the human food regime for centuries. They have been utilized as traditional herbal remedies for their ability to treat several conditions, as potent anti-oxidants, anti-diabetic and anti-carcinogenic compounds. This review summarizes our knowledge on the health-enhancing component of the anthocyanins-rich diet.

Globally, commercialized plum cultivars are mostly diploid Chinese plums (Prunus salicina Lindl.), also known as Japanese plums, and are one of the most abundant and variable fruit tree species. To advance Prunus genomic research, we present a chromosome-scale P. salicina genome assembly, constructed using an integrated strategy that combines Illumina, Oxford Nanopore, and high-throughput chromosome conformation capture (Hi-C) sequencing. The high-quality genome assembly consists of a 318.6 Mb sequence (contig N50 length of 2.3 Mb) with eight pseudochromosomes. The expansion of the P. salicina genome is led by recent segmental duplications (SDs) and a long terminal repeat (LTR) burst of ~0.2 Mya. This resulted in the significant expansion of gene families associated with flavonoid metabolism and plant resistance, which impacted fruit flavor and increased species adaptability. Population structure and domestication history suggest that Chinese plum may have been originated from South China and provides a domestication route with accompanying genomic variations. Selection sweep and genetic diversity analysis enabled the identification of several critical genes associated with flowering time, stress tolerance, and flavonoid metabolism, demonstrating the essential roles of related pathways during domestication. Furthermore, we reconstructed and exploited flavonoid-anthocyanin metabolism using multi-omics analysis in Chinese plum and proposed a complete metabolic pathway. Collectively, our results will facilitate further candidate gene discovery for important agronomic traits in Chinese plum and provide insights into future functional genomic studies and DNA-informed breeding.

Background The bast fiber crop ramie can be used as high-quality forage resources, especially in tropical or subtropical region where there is lack of high-quality protein feed. Hongxuan No.1 (HX_1) is a unique ramie variety with a light reddish brown leaf color, which is obviously different from elite cultivar, Zhongzhu No.1 (ZZ_1, green leaf). While, the regulatory mechanism of color difference or secondary metaboliates synthesis between these two varieties have not been studied. Results In this study, phenotypic, transcriptomic and metabolomic analysis of HX_1 and ZZ_1 were conducted to elucidate the mechanism of leaf color formation. Chromaticity value and pigment content measuring showed that anthocyanin was the main metabolites imparting the different leaf color phenotype between the two varieties. Based on LC/MS, at least 14 anthocyanins were identified in leaves of HX_1 and ZZ_1, and the HX_1 showed the higher relative content of malvidin-, pelargonidin-,and cyanidin-based anthocyanins. Transcriptome and metabolome co-analysis revealed that the up-regulated expression of flavonoids synthesis gene was positively correlated with total anthocyanins accumulation in ramie leaf, and the differentfially expression of “blue gene” (F3’5’H) and the “red gene” (F3’H) in leaves bring out HX_1 metabolic flow more input into the cyanidin branch. Furthermore, the enrichment of glycosylated modification pathway (UGT and AT) and the expression of flavonoid 3-O-glucosyl transferase (UFGT), anthocyanidin reductase (ANR), in leaves were significantly influenced the diversity of anthocyanins between HX_1 and ZZ_1. Conclusions Phenotypic, transcriptomic and metabolomic analysis of HX_1 and ZZ_1 indicated that the expression levels of genes related to anthocyanin metabolism contribute to the color formation of ramie variety. Anthocyanins are important plant secandary metabilates with many physiological functions, the results of this study will deepened our understanding of ramie leaf color formation, and provided basis for molecular breeding of functional forage ramie.

Yellow to red colored betalains are a chemotaxonomic feature of Caryophyllales, while in most other plant taxa, anthocyanins are responsible for these colors. The carnivorous plant family Nepenthaceae belongs to Caryophyllales; here, red‐pigmented tissues seem to attract insect prey. Strikingly, the chemical nature of red color in Nepenthes has never been elucidated. Although belonging to Caryophyllales, in Nepenthes, some molecular evidence supports the presence of anthocyanins rather than betalains. However, there was previously no direct chemical proof of this. Using ultra‐high‐performance liquid chromatography‐electrospray ionization‐high‐resolution mass spectrometry, we identified cyanidin glycosides in Nepenthes species and tissues. Further, we reveal the existence of a complete set of constitutively expressed anthocyanin biosynthetic genes in Nepenthes. Thus, here we finally conclude the long‐term open question regarding red pigmentation in Nepenthaceae., Red colors are widely distributed in tissues of carnivorous Nepenthes plants. However, whether these colors are due to the presence of anthocyanins or betalains remained unclear. Here, we employed ultra‐high‐performance liquid chromatography‐electrospray ionization‐high‐resolution mass spectrometry and identified different cyanidin glycosides in Nepenthes species and tissues. In addition, the existence of a complete set of constitutively expressed anthocyanin biosynthetic genes in Nepenthes is shown.

Flavonoids confer a wide color range to plants, thus influencing the flower quality and commercial value of various ornamental plants. Flavones and flavonols are colorless pigments that are distinct from the colored anthocyanins. Flavones and flavonols are transformed from flavanones and dihydrokaempferol, which are catalyzed by flavone synthase (FNS) and flavonol synthase (FLS), respectively, and play important roles in regulating plant growth and development, and resistance to various stresses, in addition to coloration. However, few studies have been conducted on CmFNS and CmFLS genes in chrysanthemums. In this study, we isolated and identified CmFNS and CmFLS from Chrysanthemum morifolium. CmFNS and CmFLS were constitutively expressed at different levels in various C. morifolium organs, and in vitro catalytic activity of CmFNS and CmFLS was verified. CmFNS- and CmFLS-overexpressing tobacco plants exhibited phenotypes that accumulated more flavones and flavonols, respectively, but less anthocyanins. Moreover, the transcripts of CmFNS were negatively correlated with flower color, whereas CmFLS presented an opposite trend compared to CmFNS in five flower color cultivars with different anthocyanin levels. These findings suggest that CmFNS and CmFLS act as important regulators of flavone and flavonol biosynthesis, respectively, and dicate flower coloration in chrysanthemums.

Anthocyanins are a group of natural water-soluble pigments in plants that contribute to the pink-purple color of a range of tissues. Because anthocyanins have various biological activities in human health, there is great research interest in the development of anthocyanin-rich foods and beverages, including purple shoot tea. Anthocyanidin 3-O-galactosides have been identified as one of the main anthocyanin components in purple shoot tea, but the enzyme responsible for their biosynthesis remains unclear. UDP-galactose anthocyanidin 3-O-galactosyltransferase (UA3GalT) is presumed to catalyze the galactosylation of anthocyanidin. Therefore, we assayed the UA3GalT activity in five tea samples with varying degrees of purple color and found that its activity was strongly positively correlated (r = 0.929, p

Photoprotection strategies that have evolved in plants to cope with high light (HL) stress provide plants with the ability to resist HL. However, it has not been clearly confirmed which photoprotection strategy is the major HL resistance mechanism. To reveal the major photoprotection mechanism against short-term high light (STHL), the physiological and biochemical responses of three Arabidopsis mutants (Col, chi and ans) under STHL were analyzed in this study. After STHL treatment, the most serious photosynthetic pigment damage was observed in chi plants. At the same time, the degrees of membrane and Rubisco damage in chi was the highest, followed by Col, and ans was the smallest. The results showed that ans with high antioxidant capacity showed higher resistance to STHL treatment than Col containing anthocyanins, while chi with no anthocyanin accumulation and small antioxidant capacity had the lowest resistance. In addition, the gene expression results showed that plants tend to synthesize anthocyanin precursor flavonoids with antioxidant capacity under STHL stress. To further determine the major mechanism of photoprotection under STHL, we also analyzed Arabidopsis lines (Col, CHS1, CHS2 and tt4) that had the same anthocyanin content but different antioxidant capacities. It was found that CHS2 with high antioxidant capacity had higher cell viability, smaller maximal quantum yield of PSII photochemistry (Fv/Fm) reduction and less reactive oxygen species (ROS) accumulation under HL treatment of their mesophyll protoplasts. Therefore, the antioxidant capacity provided by antioxidant substances was the major mechanism of plant photoprotection under STHL treatment.

Blackcurrant (BC) is a well-known and appreciated berry fruit in our country and Poland is the largest BC producer among European Union countries and the second, after Russia, producer in the world. Due to the short shelf life of BC, its consumption in fresh form is relatively low , therefore the berries are processed into juices, jams, jellies, and freeze-dried products or alcoholic beverages. The high nutritional value of BC berries result from high content of bioactive compounds (among others, vitamin C, anthocyanins, pectins, organic acids, as well as polyunsaturated fatty acids contained in seeds of the fruit). Anthocyanins (ANTs) create the largest group among all polyphenolic compounds contained in BC. The results from different studies confirm that ANTs are important in attenuation oxidative stress parameters in the organism, and therefore can reduce the risk of certain non-communicable chronic diseases. Consumption of unprocessed and processed blackcurrants (i.e. juices and products containing fruit extracts) may support the nutrition therapy of cardiovascular diseases, certain eye diseases and may normalize the lipid profile of the blood plasma. Additionally, the beneficial profile of unsaturated fatty acids from BC seeds supports the therapy of autoimmune diseases. This article is attempts to summarize the results of the studies on the anti-inflammatory, immunomodulatory, anti-tumor and antimicrobial effects of BC bioactive compounds including the mechanisms of their action depending on the form of the fruit (e.g. juice, whole fruit extract, dried pomace, or seed oil). The article also highlights the potential use of BC in production of functional food, important in the dietary prevention of non-communicable chronic diseases resulting from increased oxidative stress in the organism.

Background Elucidating the candidate genes and key metabolites responsible for pulp and peel coloration is essential for breeding pitaya fruit with new and improved appeal and high nutritional value. Here, we used transcriptome (RNA-Seq) and metabolome analysis (UPLC-MS/MS) to identify structural and regulatory genes and key metabolites associated with peel and pulp colors in three pitaya fruit types belonging to two different Hylocereus species. Result Our combined transcriptome and metabolome analyses suggest that the main strategy for obtaining red color is to increase tyrosine content for downstream steps in the betalain pathway. The upregulation of CYP76ADs is proposed as the color-breaking step leading to red or colorless pulp under the regulation by WRKY44 transcription factor. Supported by the differential accumulation of anthocyanin metabolites in red pulped pitaya fruit, our results showed the regulation of anthocyanin biosynthesis pathway in addition to betalain biosynthesis. However, no color-breaking step for the development of anthocyanins in red pulp was observed and no biosynthesis of anthocyanins in white pulp was found. Together, we propose that red pitaya pulp color is under the strict regulation of CYP76ADs by WRKYs and the anthocyanin coexistence with betalains is unneglectable. We ruled out the possibility of yellow peel color formation due to anthocyanins because of no differential regulation of chalcone synthase genes between yellow and green and no detection of naringenin chalcone in the metabolome. Similarly, the no differential regulation of key genes in the carotenoid pathway controlling yellow pigments proposed that the carotenoid pathway is not involved in yellow peel color formation. Conclusions Together, our results propose several candidate genes and metabolites controlling a single horticultural attribute i.e. color formation for further functional characterization. This study presents useful genomic resources and information for breeding pitaya fruit with commercially attractive peel and pulp colors. These findings will greatly complement the existing knowledge on the biosynthesis of natural pigments for their applications in food and health industry.

Early leaf removal around the cluster zone is a common technique applied in cool climate viticulture, to regulate yield components and improve fruit quality. Despite the increasing amount of information on early leaf removal and its impact on total soluble solids, anthocyanins, and polyphenols, less is known regarding aroma compounds. In order to verify the hypothesis that defoliation, applied before or after flowering, could impact the biosynthesis of thiol precursors, we performed a two year (2013 and 2014) experiment on Sauvignon blanc. We provided evidence that differential accumulation of thiol precursors in berries is affected by the timing of defoliation, and this impact was related to modifications in the biosynthetic pathway. Furthermore, the possible interaction between leaf removal treatment and seasonal weather conditions, and its effect on the biosynthesis of volatile precursors are discussed. Our results suggested that in Sauvignon blanc the relative proportion of 4-S-glutathionyl-4-methylpentan-2-one (G-4MSP) and 3-S-glutathionylhexan-1-ol (G-3SH) precursors can be affected by defoliation, and this could be related to the induction of two specific genes encoding glutathione-S-transferases (VvGST3 and VvGST5), while no significant effects on basic fruit chemical parameters, polyphenols, and methoxypyrazines were ascertained under our experimental conditions.

In this study, the effect of using medicinal plants on nutrition composition and biologically active substances in cereal mixtures were investigated. In order to develop new type of non-traditional muesli mixtures supplemented with edible flowers, eight muesli mixtures were prepared applying the mixing ratio of 60‒70% of non-traditional flakes and 30‒40% of lyophilized fruits and edible flowers. This study examines nutritional composition, digestibility, fibres and phenolics of nutraceutical muesli mixtures using enzymatic-gravimetric and chromatographic methods. It shows that the mixture of kamut, einkorn, red and black quinoa or rice flakes together with hibiscus, mallow, rose, fruits has increased the fibre content (11.9‒21.2%) and in vitro digestibility (87.8‒93.8%). The greatest concentrations of individual phenolic contents were determined in free and soluble bound fractions of the mixtures. Cyanidin-3-glucoside (up to 116 mg/kg) and delphinidin-3-glucoside (up to 76.9 mg/kg) were established as major anthocyanins. Considering the individual phenolic fractions, sinapic and protocatechuic acids were the most abundant phenolic acids and quercetin and epigallocatechin represented the most frequent flavonoids. These results indicate that non-traditional muesli with edible flowers containing a high amount of nutrients and bioactive substances have the potential to enhance a nutritionally balanced diet.

Background Although the grape berries are deliberated as a non-climacteric fruit, ethylene seems to be involved in grape berry ripening. However, the precise role of ethylene in regulating the ripening of non-climacteric fruits is poorly understood. Results Exogenous ethephon (ETH) can stimulate the concentration of internal ethylene and accelerate the accumulation of anthocyanins in berries of 'Fujiminori', including malvidin-, delphinidin-, and petunidin-derivatives (3',4',5'-trihydroxylated anthocyanins) and cyanidin-derivatives (3',4'-dihydroxylated anthocyanins). The content of 3',4',5'-trihydroxylated anthocyanins was extremely higher than 3',4'-dihydroxylated anthocyanins, and ethylene did not affect the composition of anthocyanins in grape. Furthermore, we observed the expression of anthocyanin structural and regulatory genes as well as ethylene biosynthesis and response genes in response to ETH treatment. The anthocyanins accumulation is significantly associated with increased expression of anthocyanin structural (VvPAL, Vv4CH, VvCHS, VvCHI, VvF3H, and VvUFGT) and regulatory genes (VvMYBA1, VvMYBA2, and VvMYBA3), which persisted over the 12 days. In addition, exogenous ETH affected the endogenous ethylene biosynthesis (VvACO2 and VvACO4) and the downstream ethylene regulatory network (VvERS1, VvETR2, VvCTR1, and VvERF005). Conclusions These findings bring new insights into the physiological and molecular function of ethylene during berry development and ripening in grapes. © 2021 Society of Chemical Industry.

Nitrogen regulation can effectively promote the improvement of berry components and the formation of flavor compounds in wine grapes. In order to understand the effects of foliar nitrogen spraying on grape quality and flavonoid substance, took Cabernet Sauvignon as the test subject, grape leaves were sprayed by ammonium sulfate, calcium ammonium nitrate, urea, phenylalanine, and glutamate during veraison, and clear water was used as the control. The results showed that spraying ammonium sulfate could improve the contents of soluble solids, anthocyanins, and total phenols of grape berries; spraying phenylalanine significantly increased the content of titratable acid and tannin and decreased the ratio of sugar to acid in grape berries; compared with the control group, spraying glutamate could significantly upregulate some flavonol monomers; spraying calcium ammonium nitrate can adjust the monomer content of some flavanols; urea spraying significantly increased the contents of most anthocyanins, flavanols, and flavonol and increased the contents of total anthocyanins, total flavanols, and total flavonol in grape skins, laying a foundation for the improvement of the nutritional value of grapes and wine in the future., In this experiment, ammonium sulfate, calcium ammonium nitrate, urea, phenylalanine and glutamic acid were sprayed on the leaves during veraison stage period of the grapes，spraying clean water on the leaves as a control. The results showed that spraying urea had a significant effect on the up‐regulation of most anthocyanins, flavanols and flavonol monomers, and increased the content of total anthocyanins, total flavanols, and total flavonols in grape skins.

AhRt1 controlling red testa color in peanut was fine-mapped to an interval of 580 kb on chromosome A03, and one gene encoding bHLH transcriptional factor was identified as the putative candidate gene. Peanut with red testa has higher nutritional and economic value than the traditional pink testa varieties. Identification of genes controlling red testa color will accelerate the breeding program and facilitate uncovering the genetic mechanism. In this study, in order to identify gene underlying the red testa color in peanut, a F2 population derived from a cross between a pink testa peanut variety “Fuhua 8” and a red testa variety “Quanhonghua 1” was constructed. The genetic analysis for the F2 population revealed that the red testa color was controlled by one single dominant locus. This locus, named as AhRt1 (Arachis hypogaea Red Testa 1), was preliminary identified in chromosome A03 by BSA-sequencing analysis. Using a segregation mapping population, AhRt1 was fine-mapped to a 580-kb genomic region by substitution mapping strategy. Gene candidate analysis suggested that one predicted gene encoding bHLH transcriptional factor may be the possible candidate gene for AhRt1. A diagnostic marker closely linked to candidate gene has been developed for validating the fine-mapping result in different populations and peanut germplasm. Our findings will benefit the breeding program for developing new varieties with red testa color and laid foundation for map-based cloning gene responsible for red testa in peanut.

Color acquisition is one of the most distinctive features of fruit development and ripening processes. The color red is closely related to the accumulation of polyphenolic compounds, mainly anthocyanins, during sweet cherry fruit maturity. In non-climacteric fruit species like sweet cherry, the maturity process is mainly controlled by the phytohormone abscisic acid (ABA), though other hormones may also play a role. However, the coordinated stage-specific production of polyphenolic compounds and their relation with hormone content variations have not been studied in depth in sweet cherry fruits. To further understand the accumulation dynamics of these compounds (hormones and metabolites) during fruit development, two sweet cherry cultivars ("Lapins" and "Glenred") with contrasting maturity timing phenotypes were analyzed using targeted metabolic analysis. The ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) approach revealed that phenolic acids, flavonols, and flavan-3-ols accumulated mainly until the straw-yellow stage in the early-maturing cultivar, while accumulation was mainly at the green stage in the mid-maturing cultivar, suggesting a cultivar-dependent stage-specific production of secondary metabolites. In the mid-maturing cultivar, anthocyanins were detected only from the red stage onward, whereas detection began at the pink stage in the early-maturing cultivar. ABA negatively correlated (p-value < 0.05) with the flavonols and flavan-3-ols in both cultivars. ABA and anthocyanin content increased at the same time in the early-season cultivar. In contrast, anthocyanins accumulated and the pink color initiation started several days after the ABA increase in the mid-maturing cultivar. Differential accumulation patterns of GA4, a ripening antagonizing hormone, between the cultivars could explain this difference. These results showed that both red-colored cultivars presented different accumulation dynamics of phenolic compounds and plant hormones during fruit development, suggesting underlying differences in the sweet cherry fruit color evolution.

Atherosclerosis develops due to lipid accumulation in the arterial wall and sclerosis as result of increased hyperlipidemia, oxidative stress, lipid oxidation, and protein oxidation. However, improving antioxidant status through diet may prevent the progression of atherosclerotic cardiovascular disease. It is believed that polyphenol-rich plants contribute to the inverse relationship between fruit and vegetable intake and chronic disease. Anthocyanins are flavonoid polyphenols with antioxidant properties that have been associated with reduced risk of cardiovascular disease. The consumption of anthocyanins increases total antioxidant capacity, antioxidant defense enzymes, and HDL antioxidant properties by several measures in preclinical and clinical populations. Anthocyanins appear to impart antioxidant actions via direct antioxidant properties, as well as indirectly via inducing intracellular Nrf2 activation and antioxidant gene expression. These actions counter oxidative stress and inflammatory signaling in cells present in atherosclerotic plaques, including macrophages and endothelial cells. Overall, anthocyanins may protect against atherosclerosis and cardiovascular disease through their effects on cellular antioxidant status, oxidative stress, and inflammation; however, their underlying mechanisms of action appear to be complex and require further elucidation.

Background The lace plant (Aponogeton madagascariensis) is an aquatic monocot that develops leaves with uniquely formed perforations through the use of a developmentally regulated process called programmed cell death (PCD). The process of perforation formation in lace plant leaves is subdivided into several developmental stages: pre-perforation, window, perforation formation, perforation expansion and mature. The first three emerging “imperforate leaves” do not form perforations, while all subsequent leaves form perforations via developmentally regulated PCD. PCD is active in cells called “PCD cells” that do not retain the antioxidant anthocyanin in spaces called areoles framed by the leaf veins of window stage leaves. Cells near the veins called “NPCD cells” retain a red pigmentation from anthocyanin and do not undergo PCD. While the cellular changes that occur during PCD are well studied, the gene expression patterns underlying these changes and driving PCD during leaf morphogenesis are mostly unknown. We sought to characterize differentially expressed genes (DEGs) that mediate lace plant leaf remodelling and PCD. This was achieved performing gene expression analysis using transcriptomics and comparing DEGs among different stages of leaf development, and between NPCD and PCD cells isolated by laser capture microdissection. Results Transcriptomes were sequenced from imperforate, pre-perforation, window, and mature leaf stages, as well as PCD and NPCD cells isolated from window stage leaves. Differential expression analysis of the data revealed distinct gene expression profiles: pre-perforation and window stage leaves were characterized by higher expression of genes involved in anthocyanin biosynthesis, plant proteases, expansins, and autophagy-related genes. Mature and imperforate leaves upregulated genes associated with chlorophyll development, photosynthesis, and negative regulators of PCD. PCD cells were found to have a higher expression of genes involved with ethylene biosynthesis, brassinosteroid biosynthesis, and hydrolase activity whereas NPCD cells possessed higher expression of auxin transport, auxin signalling, aspartyl proteases, cysteine protease, Bag5, and anthocyanin biosynthesis enzymes. Conclusions RNA sequencing was used to generate a de novo transcriptome for A. madagascariensis leaves and revealed numerous DEGs potentially involved in PCD and leaf remodelling. The data generated from this investigation will be useful for future experiments on lace plant leaf development and PCD in planta.

By tradition, herbal infusions have been mainly consumed for their pleasant taste, but, nowadays, the consumer, along with the pleasantness of drinking a savory beverage, also looks for their health benefits. Grapes and grape/wine by-products are a rich source of health-promoting compounds, presenting great potential for the development of new beverages. Moreover, grape-infusion preparation is no more than a sustainable or green way of extracting polyphenols and other nutraceutical compounds from grapes and grape leaves. In this review, we summarize the benefits of drinking grape infusions and discuss the sustainable processes of extracting potential nutraceutical compounds from grapes and grape by-products, which are often considered fermentation waste and are discarded to the environment without proper treatment.