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Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses, but also have higher ornamental value. Anthocyanins are vital for leaf color formation, growth and development of purple leaves. However, the molecular mechanism underlying purple leaf formation in Lagerstroemia indica remains unclear. Metabolomic and transcriptomic analysis of purple-leafed cultivar 'Ebony Embers' and greenleafed cultivar 'Arapahoe' showed that the high expression of anthocyanin structure genes induced hyperaccumulation of cyanidin and pelargonidin derivatives, making the leaves purple. LfiHY5, LfiMYB75 and LfibHLH1 were identified using correlation analysis and weighted gene co-expression network analysis. In 'Arapahoe' x 'Ebony Embers' population, LfiHY5 and LfiMYB75 showed significant positive correlation with leaf anthocyanin content. Transient expression of LfiMYB75 and LfiHY5 in tobacco and purple-leafed crape myrtle indicated that the two genes activated anthocyanin synthesis. Yeast two-hybrid analysis showed that LfiMYB75 and LfibHLH1 could form a complex that enhanced anthocyanin synthesis. Yeast monohybrid and dual-luciferase assays confirmed that LfiHY5 activated the expression of LfiMYB75, to activate the transcription of anthocyanin structural genes LfiCHS and LfiANS. Moreover, there were three alleles of LfiHY5 in crape myrtle, and the different sequences had different activation effects on LfiMYB75. In conclusion, the results showed that LfiHY5 led to upregulate the transcription of LfiMYB75, and LfiMYB75 formed a complex with LfibHLH1, which increased the transcription level of LfiCHS and LfiANS to affect anthocyanin synthesis in crape myrtle. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to develop a green, economical and efficient ultrasonic-/microwave assisted extraction (UMAE) process for the extraction of anthocyanins. Design/methodology/approach: After optimizing the extraction conditions by response surface methodology, three assays including DPPH, ABTS·+, FRAP were applied to analyze the antioxidant activity of the extracted anthocyanins. The stability under different temperatures, reductant concentrations and pHs was also discussed. The components of anthocyanins in blueberry were analyzed by HPLC-QTOF-MS2. Findings: The optimal extraction parameters were ultrasonic power of 300 W, microwave power of 365.28 W and solid–liquid ratio of 30 (g/mL). The possible structures can be speculated as Delphinidin-3-O-galactoside, Delphinidin, Petunidin, Delphinidin-3-O-glucoside, Petunidin-3-O-glucoside, Cyanidin-3-O-glucoside. The results demonstrated that the UMAE can improve the yield of anthocyanins in shorter extraction time with higher activity. Originality/value: The present study may provide a promising and feasible route for extracting anthocyanins from blueberries and studying their physicochemical properties, ultimately promoting the utilization of blueberry anthocyanins. [ABSTRACT FROM AUTHOR]

Anthocyanins are a class of natural water-soluble pigments found in plants, which are responsible for the varied colours of vegetative tissues and reproductive organs. The regulation of anthocyanin biosynthesis requires multiple factors, including enzymes, structural or regulatory genes, and transcriptional regulator proteins. While there has been notable advancement in comprehending anthocyanin biosynthesis, encompassing its structures and overarching regulation, there remains a gap in our understanding concerning the intricate interactions among various genes, molecular and biochemical mechanisms, and their feedback responses to anthocyanin regulatory networks. This article aims to provide an overview of the current understanding of the complex regulatory networks involved in the phenylpropanoid pathway, with a specific focus on anthocyanin biosynthesis. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the influence of various storage conditions on Thompson seedless (Vitis vinifera) grapes quality. Research method: Grapes were stored under four conditions: control (room temperature i.e., 20-22°C, no SO2), T1 with SO2 sheets at room temperature i.e., 20-22°C, T2 with SO2 sheets in cold storage at 1°C and T3 without SO2 sheets in cold storage at 1°C. Changes in acidity, total soluble solids (TSS), total anthocyanin content, total phenols, sugars (glucose and fructose), transresveratrol, decay %, weight loss % and antioxidant activity were monitored over 60 days. Findings: The findings revealed a synergistic effect between SO2 and cold storage. Grapes stored with both SO2 sheets and cold storage (T1) exhibited the slowest decline in anthocyanin, phenols and antioxidant activity of 211.06 mg/L, 2102.39 mg/L and 7.19 mM DPPH, respectively after 60 days. T1 grapes found to have slower reduction in sugars and transresveratrol concentration i.e., 15.47 to 15.37 g/100mL and 695 to 516 µg/g, respectively compared to control samples 15.47 to 14.81 g/100mL and 695 to 500 µg/g, respectively. Research limitations: The study focused solely on storage conditions of Thompson seedless variety grapes, limiting the generalizability of the findings to different grape varieties and maturity levels. Originality/value: These results highlighted the importance of proper storage techniques, particularly the combined use of SO2 and cold storage, for maintaining grape quality and extending shelf life. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Synchronous degradation between anthocyanin and vitamin C was found in fruit and vegetable juice matrices. To investigate whether the C‐ring of anthocyanin is the key site of this interaction, cyanidin with four different C‐ring modifications (3‐glucosylation, 3,5‐diglucosylation, 6″‐malonylation, pyranylation) was added to vitamin C‐containing apple juice, and the changes of anthocyanin retention, vitamin C retention, color, antioxidative activity and differential metabolites were analyzed.The anthocyanin retention was in the order of pyranylation >6″‐malonylation >3,5‐diglucosylation >3‐glucosylation. The vitamin C retention was in the order of 6″‐malonylation > pyranylation >3,5‐diglucosylation >3‐glucosylation. The order of color stability was the same as that of anthocyanin retention, and the order of antioxidative activity was opposite to that of vitamin C retention. The results showed that modification at the C‐ring limited the activity of anthocyanin, and suggested that the C‐ring was one of the key sites for anthocyanin and vitamin C interaction. The shared differential metabolite of all apple juice matrices added with different anthocyanins was trans‐hinokiresinol, which was likely generated from anthocyanin skeleton reacted with certain compounds in apple juice.This study showed that modification of the anthocyanin C‐ring could affect the anthocyanin and vitamin C interaction to some extent, which provided valuable insights for the application of anthocyanin C‐ring modification in shelf‐life quality control of typical fruit and vegetable beverages with the coexistence of anthocyanin and vitamin C. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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Summary: The regulatory mechanisms of anthocyanin biosynthesis have been well documented at the transcriptional and translational levels. By contrast, how anthocyanin biosynthesis is epigenetically regulated remains largely unknown.In this study, we employed genetic, molecular biology, and chromatin immunoprecipitation‐quantitative polymerase chain reaction assays to identify a regulatory module essential for repressing the expression of genes involved in anthocyanin biosynthesis through chromatin remodeling.We found that SILENCING DEFECTIVE 2 (SDE2), which was previously identified as a negative regulator for sucrose‐induced anthocyanin accumulation in Arabidopsis, is cleaved into N‐terminal SDE2‐UBL and C‐terminal SDE2‐C fragments at the first diglycine motif, and the cleaved SDE2‐C, which can fully complement the sde2 mutant, is localized in the nucleus and physically interacts with LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) in vitro and in vivo. Genetic analyses showed that both SDE2 and LHP1 act as negative factors for anthocyanin biosynthesis. Consistently, immunoblot analysis revealed that the level of LHP1‐bound histone H3 lysine 27 trimethylation (H3K27me3) significantly decreases in sde2 and lhp1 mutants, compared to wild‐type (WT). In addition, we found that sugar can induce expression of SDE2 and LHP1, and enhance the level of the nucleus‐localized SDE2‐C.Taken together, our data suggest that the SDE2‐C‐LHP1 module is required for repression of gene expression through H3K27me3 modification during sugar‐induced anthocyanin biosynthesis in Arabidopsis thaliana. See also the Commentary on this article by LaFountain, 243: 1287–1289. [ABSTRACT FROM AUTHOR]

The benefits of citrus fruits are strongly associated with their secondary metabolites. In this study, we conducted widely targeted metabolomics analyses to compare the variability of the ingredients in four scion–rootstock combinations. A total of 376 differential metabolites were obtained by a multivariate statistical analysis, and a KEGG pathway analysis showed that the enriched metabolic pathways were mainly related to the biosynthesis of flavonoids as well as lipid metabolism. The anthocyanin-targeted metabolomic features showed that cyanidin 3-O-glucoside, cyanidin 3-O-(6-O-malonyl-beta-D-glucoside), cyanidin 3-O-sophoroside, and cyanidin 3-O-xyloside were the pigments responsible for the red color of Tarocco. A lipid metabolomics analysis revealed that when Tarocco was hetero-grafted with rootstock H, there was an increase in the content of each lipid subclass, accompanied by an increase in the levels of unsaturated fatty acids, including polyunsaturated linoleic and linolenic acids, thus impacting the ratio of unsaturated fatty acids to saturated fatty acids. Additionally, we determined their antioxidant capacity ('Trifoliate orange' (Z) > 'Citrange' (ZC) > 'Hongju' (H) > 'Ziyang Xiangcheng' (X)) using in vitro assays. Finally, we utilized a network pharmacology analysis to explore the antioxidant mechanisms and potential pharmacological ingredients; we obtained 26 core targets proteins and 42 core metabolites associated with oxidative damage, providing a basis for future preventive and therapeutic applications of these metabolites. [ABSTRACT FROM AUTHOR]

The safety of food products is of prime importance for consumers and manufacturers. Many means can be used to validate a food product's safety before it is consumed. This study is about the preparation, characterization and evaluation of a generally recognized as safe (GRAS) sensitive colorimetric sensor that detects volatile gases (TVB‐N) resulting from fish spoilage, thus indicating the pH variation of packaged fish products. This is performed by coating a thin layer of ink sensors on the surface of the supporting matrix (corona‐treated PET). Various visual pH indicators were prepared based on black rice anthocyanin as an FDA‐approved dye. Black rice, which contains more than 80% cyanidin‐3‐glucoside, is the most prevalent anthocyanin component. Because of its low toxicity and high concentration, it can be utilized as a natural food colourant. pH indicators based on black rice can show distinct colours in various pH: from red (low pH) to violet (4–6) and deep purple/blue (6–7), blue (7–9) to yellowish/light brown (9–13) throughout the acid–base reaction by the analyte. The ink formulation was prepared by incorporating a binder system (PVOH‐PEG) for higher surface wettability, a crosslinking agent (citric acid) for higher adhesion, an antifoaming agent (natural vanillin) and acetic acid as a pH fixing agent. Corona treatments affected substrate surface chemistry in this study. The samples with thermal treatment passed the ASTM D3330 tape test, the 8000 passages for dry sponge and the 25 passages for wet sponge through the abrasion method. Anthocyanin concentration in formulated ink based on calculation by UV–vis spectra is 0.240 mg/100 g. Sensitivity tests towards TVB‐N gases were carried out at a temperature of 4°C to evaluate the performance of colorimetric films with formulated ink along with thermal treatment (temperature: 165°C, time: 5 min) using the volatile gases emitted by the fish sample inside the package. [ABSTRACT FROM AUTHOR]

In the agricultural areas of the Qinghai-Tibet Plateau, ultraviolet-B (UV-B) radiation varies widely. UV-B can affect the growth and development of plants. Turnip (Brassica rapa var. rapa) is an important traditional economic crop in the Qinghai-Tibet Plateau, but how turnip responds to UV-B and the complex molecular mechanisms underlying UV-B tolerance remains unclear. In this work, we found that landrace KTRG-B48b grew better and obtained a higher fresh weight of taproot in Lhasa and Kunming than landrace KTRG-B48a through common garden experiments. The phenotypic differences between the two landraces may be mechanism-based. Transcriptomes was used to analyze the differences between KTRG-B48a and KTRG-B48b. The relative expression levels of anthocyanin synthesis genes were upregulated significantly after UV-B treatment. In addition, KTRG-B48b produced less hydrogen peroxide and superoxide than KTRG-B48a. The high expression levels of anthocyanin-related genes can increase accumulation of anthocyanin, which can decrease reactive oxygen species accumulation and improved plant adaptation to the living environment of strong UV-B radiation on the Qinghai-Tibet Plateau. In this study, we proposed a model for turnip anthocyanin biosynthesis under strong UV-B radiation. Our results can provide an overview of the transcriptome response of turnip to UV-B tolerance, thus expanding our understanding the functions of anthocyanins biological in plants. [ABSTRACT FROM AUTHOR]

The light plays a key role in regulating anthocyanin biosynthesis in plants. However, the molecular basis of anthocyanin synthesis in grape skins irradiated at night with supplemental white light (W), red light (R), blue light (B), and blue light for 3 h, 6 h, 9 h, and 12 h (B3, B6, B9, and B12) is not known. In the present study, the total anthocyanin content in grape skins was significant under different light (DL) and blue-light time (DT) treatments, and the best result was obtained with B9. Analysis of RNA-seq data determined that the key genes in the anthocyanin synthesis pathway, PAL, CHS, DFR, GT, CFIP, VIT_14s0068g00920, VIT_06s0009g02860, and VIT_06s0004g08150, were significantly up-regulated under night-time supplemental light treatments, which led to the significant expression of the phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, flavone and flavonol biosynthesis, and the anthocyanin biosynthesis pathway, which were significantly expressed, promoting the accumulation of anthocyanin. The B caused significant expression of PAL (VIT_08s0040g01710), CFIP (VIT_13s0067g03820, VIT_13s0067g02870) and DFR (VIT_18s0001g12800), which may be one of the reasons for the better effect of B compared to W anthocyanin enrichment in grape skins. The DT treatment resulted in significant expression of GT (VIT_11s0052g01600), Peroxidase, VIT_09s0018g01190, and VIT_11s0037g00570. In addition, many TFs such as bHLH, MYB, ERF, WRKY, C2H2, MYB-related, and NAC were found to be involved in the synthesis of anthocyanins under light regulation. These results provide new insights into plants' nocturnal supplemental-light regulation of anthocyanin accumulation. [ABSTRACT FROM AUTHOR]

Green extraction primarily emphasizes developing new extraction techniques that consume less energy. It involves using safe, non‐toxic alternative solvents and sustainable natural resources to ensure the production of safe and high‐quality extracts. Red onion skin is an important source of anthocyanins, a subgroup of phenolic compounds. Anthocyanins are an important group of natural pigments that have attracted a lot of attention due to their health benefits. However, the instability and high sensitivity of these pigments have limited their use in food and cosmetics. Therefore, in this study, various modern green extraction methods were used, including solvent extraction, ultrasound‐assisted extraction, subcritical water extraction, microwave‐assisted extraction (MAE), pulsed electric field extraction, supercritical fluid extraction (SFE), and high hydrostatic pressure‐assisted (HHPAE) extraction, to specifically extract and purify anthocyanins. The extraction efficiency, specifically targeting anthocyanins, showed the highest efficiency with HHPAE (81.84%) and the lowest with MAE (40.01%). Measurement of total anthocyanin content revealed that HHPAE and SFE methods yielded the highest anthocyanin concentrations, with 248.49 and 244.98 mg/L, respectively. Identification of anthocyanin by LC–MS revealed that the main anthocyanidins in red onion peel are pelargonidin, cyanidin, delphinidin, and petunidin. These results indicate that innovative green extraction methods, particularly HHPAE and SFE, can effectively replace conventional techniques due to their superior efficiency and enhanced preservation of anthocyanin compounds. [ABSTRACT FROM AUTHOR]

Ficus carica is an economically important horticultural plant. Due to its abundant secondary metabolites, F. carica has gained interest for its applications in medicine and as a nutritional supplement. Both external and internal factors affect the accumulation of secondary metabolites in F. carica. The assembly of the F. carica genome has facilitated functional analysis of key genes and transcription factors associated with the biosynthesis of secondary metabolites, particularly anthocyanin. In this review, we summarize the various types and functions of secondary metabolites, with a particular focus on flavonoids, coumarins, and terpenes. We also explore the factors influencing their biosynthesis and accumulation, including varieties, tissue, environmental factors (e.g., light), stresses (e.g., high temperature, low temperature, drought, nutrient deficiencies, salinity), hormonal treatments, and developmental factors. Furthermore, we discuss the involvement of structural genes and transcription factors in the biosynthesis of secondary metabolites, specifically anthocyanin and furanocoumarins, knowledge of which will promote the breeding and genetic engineering of novel F. carica varieties. [ABSTRACT FROM AUTHOR]

Featured Application: Featured Application: A Design of Experiments approach and multivariate analysis can help to understand the complex relationship between the chemical profile and the extraction conditions in the preparation of liqueurs such as the myrtle alcoholic drink. Preparation of myrtle liqueur through ethanol-based extraction is a widely employed methodology. Nevertheless, optimization of existing processes is possible, especially through a modern statistical multivariate approach. In this context, a Design of Experiments (DoE) approach was used to quantitatively assess for the first time the effect of the time, ethanol concentration, temperature, and the ratio between the Myrtus communis berries' weight and the extractant volume (v/w) on the amounts of anthocyanins, volatile compounds and dry residues in the liqueur. The kinetic profile relative to the volatile fraction variation during the process was described by gas chromatography (GC), while spectrophotometric analysis allowed quantification of the total anthocyanins and total polyphenols. Multiple response analysis showed that the maximum efficiencies in terms of the considered parameters (desirability function) were reached by setting the temperature to 25 °C and the ethanol percentage to 96% after 20 days of processing. Some hints as to the chemical instability and not negligible sensitivity of anthocyanins in relation to the experimental conditions for longer extraction times were also observed. The statistical model represents a novel tool for industrial production of myrtle liqueur. [ABSTRACT FROM AUTHOR]

Hg(II), poses a significant threat to both the environment and overall well‐being. The present indicator utilizes anthocyanin extract from roselle (Hibiscus sabdariffa), RSE, and incorporates it into bacterial cellulose nanofibers (BCNF) to detect Hg(II) ions. Through examination of the CIE Lab color variables, it is determined that the binding of Hg(II) leads to a discernible alteration in the color. The visible color changes as the Hg(II) concentration increases. ATR‐FTIR(Attenuated Total Reflectance‐Fourier transform infrared spectroscopy) and SEM(scanning electron microscopy) are utilized to analyze the bacterial cellulose nanofibers containing anthocyanin. The selectivity of the proposed sensor is assessed by conducting experiments with different types of metal ions including Co2+, Al3+, Na+, Ba2+, Ni2+, Mg2+, Cd2+, Pb2+, Fe2+, Fe3+, and Cu2+. The outcomes indicate that the sensor exhibits a remarkable ability to distinguish and respond specifically to Hg(II) ions. This particular sensing technique allows for the precise and reliable detection of Hg(II), with a detection limit of 0.72 ppm, by simply observing with the naked eye. For the effective treatment of a tap water sample, the BCNF‐RSE film provides successful results in the detection of Hg(II) ions. This innovative metallochromic sensor offers a promising solution for the on‐site, cost‐effective, portable, easy to use, and real‐time detection of Hg(II) ions. [ABSTRACT FROM AUTHOR]

Several studies have demonstrated the antioxidant and anti-inflammatory properties of anthocyanins, as well as their potential phytoestrogenic activity, which could have positive effects on human health. These compounds have shown effectiveness against conditions such as obesity, diabetes, and high cholesterol, which are known risk factors for cardiovascular diseases, including stroke. Stroke is currently the second leading cause of death globally, and cerebral small vessel disease (CSVD) accounts for 20% of all strokes, and it often causes cognitive impairment and gait abnormalities in older adults. Anthocyanins and their metabolites can cross the blood–brain barrier and affect signaling pathways, gene expression, and protein function at the molecular level. In addition to their ability to enhance vascular flow, anthocyanins can also help mitigate the risk factors associated with CSVD by counteracting oxidative stress in the body. These findings exploring the potential benefits of anthocyanins for individuals with CSVD. [ABSTRACT FROM AUTHOR]

Background: Based on our previous research, a full-length cDNA sequence of HvANS gene was isolated from purple and white Qingke. The open reading frame (ORF) in the purple variety Nierumuzha was 1320 base pairs (bp), encoding 439 amino acids, while the ORF in the white variety Kunlun 10 was 1197 bp, encoding 398 amino acids. A nonsynonymous mutation was found at the position of 1195 bp (T/C) in the coding sequence (CDS) of the HvANS gene. We carried out a series of studies to further clarify the relationship between the HvANS gene and anthocyanin synthesis in Qingke. Results: The conservative structural domain prediction results showed that the encoded protein belonged to the PLN03178 superfamily. Multiple comparisons showed that this protein had the highest homology with Hordeum vulgare, at 88.61%. The approximately 2000 bp promoter sequence of the HvANS gene was identical in both varieties. The real-time fluorescence PCR (qRT-PCR) results revealed that HvANS expression was either absent or very low in the roots, stems, leaves, and awns of Nierumuzha. In contrast, the HvANS expression was high in the seed coats and seeds of Nierumuzha. Likewise, in Kunlun 10, HvANS expression was either absent or very low, indicating a tissue-specific and variety-specific pattern for HvANS expression. The subcellular localization results indicated that HvANS was in the cell membrane. Metabolomic results indicated that the HvANS gene is closely related to the synthesis of three anthocyanin substances (Idaein chloride, Kinetin 9-riboside, and Cyanidin O-syringic acid). Yeast single hybridization experiments showed that the HvANS promoter interacted with HvANT1, which is the key anthocyanin regulatory protein. In a yeast two-hybrid experiment, we obtained two significantly different proteins (ZWY2020 and POMGNT2-like) and verified the results by qRT-PCR. Conclusions: These results provide a basis for further studies on the regulatory mechanism of HvANS in the synthesis of anthocyanins in Qingke purple grains. [ABSTRACT FROM AUTHOR]

Waxy corn (Zea mays var. ceratina) is a pigmented corn rich in anthocyanins. Numerous studies have proved various biological activities of anthocyanins, and one of them is antioxidants. Antioxidants will donate electrons to stop or reduce rampaging free radicals in target particles. Several methods have been used to improve pigmented waxy corn's anthocyanin content, and one of them is conventional breeding through the reciprocal cross. Thus, this research investigates the effects of reciprocal cross on the anthocyanin content and its antioxidant activity in waxy corn. The total anthocyanin content (TAC) was determined using the pH differential method. On the other hand, the total phenolic content (TPC) was analyzed by the Folin- Ciocalteu colorimetric method. Then, the antioxidant activity was assayed through 2,2-Diphenyl-2-hydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. The results indicated that hybrid BL 1-7 x BL 1-8 had the highest TAC and TPC at 71.43 mg/100g and 7.04 mg of GAE/g, respectively. BL 1-7 x BL 1-8 had the lowest IC50 values which are 133.68 ug/mL for DPPH assay and 17.13 ug/mL for ABTS assay. It is an exciting finding from this study to utilize inbred BL 1-7 as maternal plant for enhancement of anthocyanin content and antioxidant activity. Furthermore, TAC and TPC were significantly correlated with DPPH and ABTS activity. These correlations helped to add more information on the relationship between phytochemicals and antioxidant activity. The information obtained from this study is useful for making smart selection of inbreds that will result in new waxy corn hybrids that are full of health advantages and provide functional foods like natural colorants. [ABSTRACT FROM AUTHOR]

Flavonoids are polyphenolic plant constituents. Anthocyanins are flavonoid pigments found in higher plants that show a wide variety of colors ranging from red through purple to blue. The blue color of the flowers is mostly attributed to anthocyanins. However, only a few types of anthocyanidin, chromophore of anthocyanin, exist in nature, and the extracted pigments are unstable with the color fading away. Therefore, the wide range and stable nature of colors in flowers have remained a mystery for more than a century. The mechanism underlying anthocyanin-induced flower coloration was studied using an interdisciplinary method involving chemistry and biology. Furthermore, the chemical studies on flavonoid pigments in various edible plants, synthetic and biosynthetic studies on anthocyanins were conducted. The results of these studies have been outlined in this review. [ABSTRACT FROM AUTHOR]

Anthocyanin can improve the stress tolerance and disease resistance of winter wheat to a certain extent, so timely and accurate monitoring of anthocyanin content is crucial for the growth and development of winter wheat. This study measured the ground-based hyperspectral reflectance and the corresponding anthocyanin concentration at four key growth stages—booting, heading, flowering, and filling—to explore the spectral detection of anthocyanin in winter wheat leaves. Firstly, the first-order differential spectra (FDS) are obtained by processing based on the original spectra (OS). Then, sensitive bands (SBS), the five vegetation indices for optimal two-band combinations (VIo2), and the five vegetation indices for optimal three-band combinations (VIo3) were selected from OS and FDS by band screening methods. Finally, modeling methods such as RF, BP, and KELM, as well as models optimized by genetic algorithm (GA), were used to estimate anthocyanin content at different growth stages. The results showed that (1) among all the models, the GA_RF had incredible performance, VIo3 was the superior parameter for estimating anthocyanin values, and the model GA_RF of FDS data based on VIo3 for the filling stage (Rv2 = 0.950, RMSEv = 0.005, RPDv = 4.575) provided the best estimation of anthocyanin. (2) the first-order differential processing could highlight the degree of response of SBS, VIo2, and VIo3 to the anthocyanin values. The model performances of the FDS were better than that of OS on the whole, and the Rv2 of the optimal models of FDS were all greater than 0.89. (3) GA had optimizing effects on the RF, BP, and KELM, and overall, the GA models improved the R2 by 0.00%-18.93% compared to the original models. These results will provide scientific support for the use of hyperspectral techniques to monitor anthocyanin in the future. [ABSTRACT FROM AUTHOR]

The color of red-skinned pear (Pyrus spp.) is primarily attributed to accumulation of anthocyanins, which provide nutritional benefits for human health and are closely associated with the commercial value of fruits. Here, we reported the functional characterization of a R2R3-MYB repressor PyMYB107, which forms an 'activator-repressor' loop to control anthocyanin accumulation in the red-skinned pear. PyMYB107 overexpression inhibited anthocyanin biosynthesis in both pear calli and fruits, while virus-induced gene silencing of PyMYB107 increased anthocyanin accumulation in pear fruits. Furthermore, ectopic expression of PyMYB107 decreased anthocyanin accumulation in tomato, strawberry and tobacco. PyMYB107 can competitively bind to PybHLH3 with PyMYB10/MYB114, thereby suppressing the transcriptional activation of key anthocyanin biosynthesis genes, PyANS and PyUFGT. Site-directed mutagenesis showed that mutations within the R3 domain and EAR motif of PyMYB107 eliminated its repressive activity. Additionally, PyMYB107 exhibited a comparable expression pattern to PyMYB10/MYB114 and was transcriptionally activated by them. Our finding advanced comprehension of the repression mechanism underlying anthocyanin accumulation, providing valuable molecular insights into improving quality of pear fruits. [ABSTRACT FROM AUTHOR]

In order to study the effective method of the enrichment and purification of anthocyanin in black wolfberry and mulberry, and identify the structure of anthocyanin, the black wolfberry and mulberry extracts were purified by macroporous resins. The adsorption and desorption abilities of different types of the resins for anthocyanins were compared. LX-20SS was optimized as the resin for the purification of anthocyanins from black wolfberry. The purification conditions were as follows: The mass ratio of resin to crude anthocyanin powder of black wolfberry was at 10:1, and the elution concentration of ethanol was 70%, and the flow rate was 3 mL/min. After the purification, the content of anthocyanin reached 144.18±3.40 mg/g. DM-21 was optimized as the resin for the purification of mulberry anthocyanin. The purification conditions were as follows: The mass ratio of resin to crude anthocyanin powder of mulberry was at 20:3, and the elution concentration of ethanol was 30%, and the flow rate was 1 mL/min. The content of anthocyanin reached 112.44±2.24 mg/g after purification. High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis for anthocyanin structures in black wolfberry and mulberry showed that the main anthocyanin in black wolfberry was petunidin-3-O-rutinose (p-coumaroyl)-5-O-glucoside, which accounted for more than 95% of the total anthocyanin. In addition, there are two main types of anthocyanins in mulberry, corresponding to cyanidin-3-glucoside and cyanidin-3- rutinoside, which accounted for 63.58% and 36.42% of the total anthocyanins respectively. The results provided references for the development of black wolfberry and mulberry. [ABSTRACT FROM AUTHOR]

Zelkova schneideriana is a landscaping flowering and deciduous plant whose leaf color changes in the fall season. In the discoloration period, the anthocyanin content in the red lines of Z. schneideriana is 3.52 times greater than that in the green lines, whereas the chlorophyll content in the red lines is 20.10 times lower. To understand the molecular mechanism of the leaf discoloration, transcriptome sequencing was performed. A total of 3965 differentially expressed genes (DEGs) were identified between the red and green lines in the discoloration period. These DEGs were mainly involved in plant–pathogen interactions, the MAPK signaling pathway, plant hormone signal transduction, flavonoid biosynthesis, and anthocyanin biosynthesis. Among them, three downregulated genes were involved in chlorophyll synthesis; these genes exhibited a maximum decrease in the red lines that was 11.13 times greater than their expression in the green lines. In contrast, 33 upregulated genes were involved in anthocyanin biosynthesis; they exhibited a maximum increase in the red lines 4645.33 times greater than their expression in the green lines. The results of an association analysis revealed that four transcription factors, including ZeBHLH42, ZeMYB123, ZeMYB113, and ZeWRKY44, positively regulated the anthocyanin synthesis genes. These results explained the mechanism underlying the discoloration of Zelkova leaves and provided a basis for molecular breeding programs of colorful plants. [ABSTRACT FROM AUTHOR]

Anthocyanins, a significant subclass of polyphenols, are prevalent across various plant species. Known for their vibrant colors, which make them desirable as natural pigments, anthocyanins have also garnered attention for their diverse biological activities, leading to their widespread use in food processing and supplement development. However, their structural instability poses a challenge, as it directly impacts their bioavailability and, consequently, their nutritional efficacy. This review paper delves into the chemical structure and food sources of anthocyanins and examines strategies to enhance their stability and bioavailability, particularly through improved understanding of their digestion and absorption in the human body. Additionally, it explores the broad spectrum of anthocyanins’ biological activities, including their antioxidant, hypoglycemic, anticancer, cardiovascular, anti-inflammatory, and neuroprotective effects, analyzing these properties from a mechanistic perspective. Factors such as pH, temperature, light exposure, solvent interactions, and metal ions are known to negatively affect anthocyanin stability. Thus, future research should prioritize processing techniques that can preserve their structure more effectively. [ABSTRACT FROM AUTHOR]

Radish exhibits significant variation in color, particularly in sprouts, leaves, petals, fleshy roots, and other tissues, displaying a range of hues such as green, white, red, purple, and black. Although extensive research has been conducted on the color variation of radish, the underlying mechanism behind the variation in radish flower color remains unclear. To date, there is a lack of comprehensive research investigating the variation mechanism of radish sprouts, leaves, fleshy roots, and flower organs. This study aims to address this gap by utilizing transcriptome sequencing to acquire transcriptome data for white and purple radish flowers. Additionally, the published transcriptome data of sprouts, leaves, and fleshy roots were incorporated to conduct a systematic analysis of the regulatory mechanisms underlying anthocyanin biosynthesis in these four radish tissues. The comparative transcriptome analysis revealed differential expression of the anthocyanin biosynthetic pathway genes DFR, UGT78D2, TT12 and CPC in the four radish tissues. Additionally, the WGCNA results identified RsDFR.9c and RsUGT78D2.2c as hub genes responsible for regulating anthocyanin biosynthesis. By integrating the findings from the comparative transcriptome analysis, WGCNA, and anthocyanin biosynthetic pathway-related gene expression patterns, it is hypothesized that genes RsDFR.9c and RsUGT78D2.2c may serve as pivotal regulators of anthocyanins in the four radish tissues. Furthermore, the tissue-specific expression of the four copies of RsPAP1 is deemed crucial in governing anthocyanin synthesis and accumulation. Our results provide new insights into the molecular mechanism of anthocyanin biosynthesis and accumulation in different tissues of radish. [ABSTRACT FROM AUTHOR]

Summary: In plant species, anthocyanin accumulation is specifically regulated by light signaling. Although the CONSTITUTIVELY PHOTOMORPHOGENIC1/SUPPRESSOR OF PHYA‐105 (COP1/SPA) complex is known to control anthocyanin biosynthesis in response to light, the precise mechanism underlying this process remains largely unknown.Here, we report that Increase in BONSAI Methylation 1 (IBM1), a JmjC domain‐containing histone demethylase, participates in the regulation of light‐induced anthocyanin biosynthesis in Arabidopsis.The expression of IBM1 was induced by high light (HL) stress, and loss‐of‐function mutations in IBM1 led to accelerated anthocyanin accumulation under HL conditions. We further identified that IBM1 is directly associated with SPA1/3/4 chromatin in vivo to establish a hypomethylation status on H3K9 and DNA non‐CG at these loci under HL, thereby releasing their expression. Genetic analysis showed that quadruple mutants of IBM1 and SPA1/3/4 resemble spa134 mutants. Overexpression of SPA1 in ibm1 mutants complements the mutant phenotype.Our results elucidate the significance and mechanism of IBM1 histone demethylase in the epigenetic regulation of anthocyanin biosynthesis in Arabidopsis under HL conditions. [ABSTRACT FROM AUTHOR]

This study investigates the impact of anthocyanin treatment on rice plants under drought stress, focusing on phenotypic, molecular, and biochemical responses. Anthocyanin were treated to one month old plants one week before the droughtexposure. Drought stress was imposed by using 10% polyethylene glycol (PEG 6000). Anthocyanin-treated plants exhibited significant enhancements in various traits, including growth parameters and reproductive characteristics, under normal conditions. When subjected to drought stress, these plants displayed resilience, maintaining or improving essential morphological and physiological features compared to non-treated counterparts. Notably, anthocyanin application mitigated drought-induced oxidative stress, as evidenced by reduced levels of reactive oxygen species (ROS) and lipid membrane peroxidation. The study also elucidates the regulatory role of anthocyanins in the expression of flavonoid biosynthetic genes, leading to increased levels of key secondary metabolites. Furthermore, anthocyanin treatment influenced the levels of stress-related signaling molecules, including melatonin, proline, abscisic acid (ABA), and salicylic acid (SA), contributing to enhanced stress tolerance. The enzymatic activity of antioxidants and the expression of drought-responsive genes were modulated by anthocyanins, emphasizing their role in antioxidant defense and stress response. Additionally, anthocyanin treatment positively influenced macronutrient concentrations, particularly calcium ion (Ca+), potassium ion (K+), and sodium ion (Na+), essential for cell wall and membrane stability. The findings collectively highlight the multifaceted protective effects of anthocyanins, positioning them as potential key players in conferring resilience to drought stress in rice plants. The study provides valuable insights into the molecular and physiological mechanisms underlying anthocyanin-mediated enhancement of drought stress tolerance, suggesting promising applications in agricultural practices for sustainable crop production. [ABSTRACT FROM AUTHOR]

Tarhana, which is very rich in nutritional value, has been the crown of our tables for centuries and is one of our common values wherever we live. It is obtained with black carrot extract to give this special food an even richer form. Black carrot extract was used to increase the anthocyanin content of the tarhana. In this study, physical and chemical analyzes, total phenolic content and total flavonoid content, antioxidant activities, colour measurement, sensory analysis of tarhana prepared with black carrot extract were determined. At the same time, the total amount of monomeric anthocyanin was determined. All these values were compared with classical tarhana and it was determined that tarhana containing black carrot extract had high DPPH activity (4.21±1.78 mg/mL) and high anthocyanin content (19.14±2.02 mg cyn3-glu/kg sample). According to the sensory analysis, the acceptability of tarhana with black carrot extract was determined to be high. [ABSTRACT FROM AUTHOR]

In nature, hydrogen bonding is a common physical occurrence that has a significant impact on the surroundings of anthocyanins. Water molecules will create hydrogen bonds with anthocyanin molecules in various configurations, but the characteristics of these hydrogen bonds will change. Varied hydrogen bonding characteristics have varied impacts on solvent solutions. This research analyzes the differences in hydrogen bonding qualities caused by different methyl structures, as well as the underlying explanations. In this study, the cyanidin and peonidin structures of anthocyanin molecules were calculated in various stable hydrogen bond configurations using the density functional theory B3LYP/6‐31G(d,p), combined with information from the infrared spectroscopy spectrum, atoms in molecules analysis, interaction energy E, and intermolecular hydrogen bond length. The hydrogen bond structure that is the most stable is determined by analyzing it, as well as the effects of replacing the hydroxyl group with a methyl group and any potential underlying causes. Future anthocyanins research can benefit from the precise theoretical reference that this study can offer. [ABSTRACT FROM AUTHOR]

SUMMARY: Apple rust is a serious fungal disease affecting Malus plants worldwide. Infection with the rust pathogen Gymnosporangium yamadae induces the accumulation of anthocyanins in Malus to resist rust disease. However, the mechanism of anthocyanin biosynthesis regulation in Malus against apple rust is still unclear. Here, we show that MpERF105 and MpNAC72 are key regulators of anthocyanin biosynthesis via the ethylene‐dependent pathway in M. 'Profusion' leaves under rust disease stress. Exogenous ethephon treatment promoted high expression of MpERF105 and MpNAC72 and anthocyanin accumulation in G. yamadae‐infected M. 'Profusion' leaves. Overexpression of MpERF105 increased the total anthocyanin content of Malus plant material and acted by positively regulating its target gene, MpMYB10b. MpNAC72 physically interacted with MpERF105 in vitro and in planta, and the two form a protein complex. Coexpression of the two leads to higher transcript levels of MpMYB10b and higher anthocyanin accumulation. In addition, overexpression of MpERF105 or MpNAC72 enhanced the resistance of M. 'Profusion' leaves to apple rust. In conclusion, our results elucidate the mechanism by which MpERF105 and MpNAC72 are induced by ethylene in G. yamadae‐infected M. 'Profusion' leaves and promote anthocyanin accumulation by mediating the positive regulation of MpMYB10b expression. Significance Statement: Ethylene‐induced MpERF105 and MpNAC72 promote the expression of MpMYB10b and thus regulate anthocyanin accumulation in Malus 'Profusion' leaves under rust conditions. [ABSTRACT FROM AUTHOR]

SUMMARY: Anthocyanin generation in apples (Malus domestica) and the pigmentation that results from it may be caused by irradiation and through administration of methyl jasmonate (MeJA). However, their regulatory interrelationships associated with fruit coloration are not well defined. To determine whether MdERF109, a transcription factor (TF) involved in light‐mediated coloration and anthocyanin biosynthesis, has synergistic effects with other proteins, we performed a yeast two‐hybrid assessment and identified another TF, MdWER. MdWER was induced by MeJA treatment, and although overexpression of MdWER alone did not promote anthocyanin accumulation co‐overexpression with MdERF109 resulted in significantly increase in anthocyanin biosynthesis. MdWER may form a protein complex with MdERF109 to promote anthocyanin accumulation by enhancing combinations between the proteins and their corresponding genes. In addition, MdWER, as a MeJA responsive protein, interacts with the anthocyanin repressor MdJAZ2. Transient co‐expression in apple fruit and protein interaction assays allowed us to conclude that MdERF109 and MdJAZ2 interact with MdWER and take part in the production of anthocyanins upon MeJA treatment and irradiation. Our findings validate a role for the MdERF109‐MdWER‐MdJAZ2 module in anthocyanin biosynthesis and uncover a novel mechanism for how light and MeJA signals are coordinated anthocyanin biosynthesis in apple fruit. Significance Statement: Our findings validate a role for the MdERF109‐MdWER‐MdJAZ2 module in anthocyanin biosynthesis and uncover a novel mechanism for how light and MeJA signals are coordinated anthocyanin biosynthesis in apple fruit. [ABSTRACT FROM AUTHOR]

The spines of Chinese red chestnut are red and the depth of their color gradually increases with maturity. To identify the anthocyanin types and synthesis pathways in red chestnut and to identify the key genes regulating the anthocyanin biosynthesis pathway, we obtained and analyzed the transcriptome and anthocyanin metabolism of red chestnut and its control variety with green spines at 3 different periods. GO and KEGG analyses revealed that photosynthesis was more highly enriched in green spines compared with red spines, while processes related to defense and metabolism regulation were more highly enriched in red spines. The analysis showed that the change in spine color promoted photoprotection in red chestnut, especially at the early growth stage, which resulted in the accumulation of differentially expressed genes involved in the defense metabolic pathway. The metabolome results revealed 6 anthocyanins in red spines. Moreover, red spines exhibited high levels of cyanidin, peonidin and pelargonidin and low levels of delphinidin, petunidin and malvidin. Compared with those in the control group, the levels of cyanidin, peonidin, pelargonidin and malvidin in red spines were significantly increased, indicating that the cyanidin and pelargonidin pathways were enriched in the synthesis of anthocyanins in red spines, whereas the delphinidin pathways were inhibited and mostly transformed into malvidin. During the process of flower pigment synthesis, the expression of the CHS, CHI, F3H, CYP75A, CYP75B1, DFR and ANS genes clearly increased, that of CYP73A decreased obviously, and that of PAL, 4CL and LAR both increased and decreased. Notably, the findings revealed that the synthesized anthocyanin can be converted into anthocyanidin or epicatechin. In red spines, the upregulation of BZ1 gene expression increases the corresponding anthocyanidin content, and the upregulation of the ANR gene also promotes the conversion of anthocyanin to epicatechin. The transcription factors involved in color formation included 4 WRKYs. [ABSTRACT FROM AUTHOR]

Long-term aging has traditionally been associated with issues such as color fading and oxidation; therefore, it limits grape wine production. Here, we analyzed 90 bottles of mulberry wine aged for various periods (up to 12 years) and observed unique trends in color, flavor, and aroma compounds during prolonged aging. Results from Somers and methylcellulose precipitation (MCP) assays indicated that the tannin and anthocyanin concentrations in newly fermented mulberry wines were 167 to 216 mg/L and 1.04 to 1.37 g/L, respectively. The total phenolics, tannins, and anthocyanin contents exhibited significant negative correlations with aging years, while the non-bleachable pigment content and hue showed positive correlations with aging times. High-performance liquid chromatography–electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) analysis further revealed a positive correlation between the content of pyranoanthocyanins (including cyanidin-3-O-glucoside-pyruvic acid, cyanidin-3-O-glucoside-acetaldehyde, cyanidin-3-O-glucoside-4-vinocatechol, and cyanidin-3-O-glucoside-4-vinophenol) and aging times, whereas the impacts of aging on the polymeric pigment (cyanidin-3-O-glucoside-epicatechin) were not observed. This suggests that the anthocyanins in mulberry wine primarily transformed into pyranoanthocyanins rather than polymeric pigments during aging. The aging-induced reductions in protein, polysaccharide, and key aroma compounds (contributing to the fruity, sweet and floral odors) remained unaffected by prolonged aging. [ABSTRACT FROM AUTHOR]

Despite extensive research highlighting the pivotal role of MYB transcription factors in regulating anthocyanin biosynthesis, the interactive regulatory network involving these MYB factors in pear fruits remains inadequately characterized. In this study, the anthocyanin-regulatory gene PbrMYB114 was successfully cloned from 'Yuluxiang' pear (Pyrus bretschneideri) fruits, and its influence on anthocyanin accumulation was confirmed through transient expression assays. Specifically, the co-transformation of PbrMYB114 with its partner PbrbHLH3 in pears served to validate the functional role of PbrMYB114. Subsequently, PbrMYB114 was employed as bait in a yeast two-hybrid screening assay, using a 'Yuluxiang' pear protein library, which led to the identification of 25 interacting proteins. Further validation of the interactions between PbrMYB114 and PbrMT2/PbrMT3 was conducted. Investigations into the role of PbrMT2 and PbrMT3 in 'Duli' seedlings (Pyrus betulaefolia) revealed their potential to enhance anthocyanin accumulation. The outcomes of these studies provide novel insights into the protein network that regulates pear anthocyanin biosynthesis, particularly the functional interactions among PbrMYB114 and associated proteins. [ABSTRACT FROM AUTHOR]

The quality of rosé wines significantly depends on their phenolic composition, particularly tannins, anthocyanins, and their derivatives, which determine the perceived color of these products and their color evolution throughout the storage and shelf-life periods. This study investigated the impact of phenolic content on the oxidation and color evolution of five different model rosé wines obtained by blending a fixed amount of grape tannins with varying concentrations of oenocyanin to modulate their respective ratio and color intensity. The solutions were monitored for color and pigment changes promoted by oxidation in a Fenton-like environment. The findings revealed a potential correlation between the initial phenolic concentration and the different degrees of oxidation within each solution, resulting in significant variations in CIELAB data. Overall, all solutions exhibited a substantial decrease in redness, with losses ranging from 23% in the darkest solution to 43% in the lightest one compared to their initial levels. Additionally, their color profiles shifted toward yellow hues, up to triple the original value, indicating the degradation of the pigments responsible for the characteristic rosé color. Greater amounts of anthocyanins preserved higher Fe(II) concentrations over time, suggesting the antioxidant role of these compounds. The whole dataset also permitted the evaluation of the different oxidation susceptibilities of individual anthocyanins, among which derived pigments, such as vitisins, proved to be notably more stable than native pigments, particularly delphinidin and petunidin. [ABSTRACT FROM AUTHOR]

In this paper, an intelligent film was developed using the cast film process, with acetylated distarch phosphate (ADSP) and polyvinyl alcohol (PVA) as substrates. Red cabbage anthocyanin extracts (RCAE) were incorporated as visual indicators of pH changes. This study aimed to enhance the mechanical strength and barrier properties of ADSP-based films by introducing PVA. The impacts of the ADSP/PVA ration on the film's microstructure, physical, optical and mechanical properties were evaluated. In addition, the pH responsiveness of the intelligent film and the sensitivity to ammonia were investigated. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) showed that adding PVA improved the density of films by forming hydrogen bonds. X-ray diffraction (XRD) results showed that the diffraction peak intensity of the intelligent films increased with the increase of PVA content. When the volume ratio of PVA to the ADSP solution was 5:5, the water resistance, oxygen barrier, and tensile strength increased by 43.41%, 36.30%, and 50.00%, respectively, compared with pure ADSP films. Moreover, the light-blocking ability of films was enhanced by adding anthocyanins. The anthocyanin-rich films were proved to exhibit an obvious color response to pH. The sensitivity test of volatile ammonia showed that the color of intelligent films had different reactions with the increase in ammonia concentration. Notably, the detection limit of the prepared intelligent films for volatile ammonia was 1 ppm. This study proposed a promising avenue for the development of intelligent packaging materials. The practical application of these materials in the field of packaging needs to be further explored. [ABSTRACT FROM AUTHOR]

The red Chinese sand pear (Pyrus pyrifolia Nakai) is native to China and exhibits a unique fruit coloration pattern. Flavonoid 3′-hydroxylase (F3′H) catalyzes the hydroxylation of flavonoids, which subsequently determines the components of anthocyanins and the color of plant organs. Two genes encoding flavonoid 3′-hydroxylase (F3′H), PpF3′HI and PpF3′HII, have been identified in red Chinese sand pears. The coding regions for PpF3′HI and PpF3′HII were 1542 and 1536 bp in length, respectively. PpF3′HI shared 95% of its amino acid sequence identity with PpF3′HII, and a highly conserved P450 superfamily domain was found both in PpF3′HI and in PpF3′HII. Phylogenetic analysis showed that PpF3′HI and PpF3′HII clustered with MdF3′HI and MdF3′HII, respectively. PpF3′H genes were highly expressed in anthocyanin-enriched tissues such as young leaves, and transcription of PpF3′H genes corresponded to anthocyanin biosynthesis during the developmental stages, bagging treatment, and postharvest UV-B/visible irradiation treatment. A Y1H assay showed that PpMYB10 and PpHY5 could interact with the −419 bp to 0 bp and −746 bp to −396 bp fragments of the PpF3′HI promoter region, respectively. Understanding the mechanism of flavonoid hydroxylation patterns will, in turn, promote the development of new technologies for modifying flavonoid and anthocyanin composition in fruits. [ABSTRACT FROM AUTHOR]

Flavonol synthase gene (FLS) is a member of the 2-oxoglutarate-dependent dioxygenase (2-ODD) superfamily and plays an important role in plant flavonoids biosynthetic pathways. Safflower (Carthamus tinctorius L.), a key source of traditional Chinese medicine, is widely cultivated in China. Although the flavonoid biosynthetic pathway has been studied in several model species, it still remains to be explored in safflower. In this study, we aimed to elucidate the role of CtFLS1 gene in flavonoid biosynthesis and drought stress responses. The bioinformatics analysis on the CtFLS1 gene showed that it contains two FLS-specific motifs (PxxxIRxxxEQP and SxxTxLVP), suggesting its independent evolution. Further, the expression level of CtFLS1 in safflower showed a positive correlation with the accumulation level of total flavonoid content in four different flowering stages. In addition, CtFLS1-overexpression (OE) Arabidopsis plants significantly induced the expression levels of key genes involved in flavonol pathway. On the contrary, the expression of anthocyanin pathway-related genes and MYB transcription factors showed down-regulation. Furthermore, CtFLS1-OE plants promoted seed germination, as well as resistance to osmotic pressure and drought, and reduced sensitivity to ABA compared to mutant and wild-type plants. Moreover, CtFLS1 and CtANS1 were both subcellularly located at the cell membrane and nucleus; the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assay showed that they interacted with each other at the cell membrane. Altogether, these findings suggest the positive role of CtFLS1 in alleviating drought stress by stimulating flavonols and anthocyanin accumulation in safflower. [ABSTRACT FROM AUTHOR]

Fruit color is an intuitive quality of horticultural crops that can be used as an evaluation criterion for fruit ripening and is an important factor affecting consumers' purchase choices. In this study, a genetic population from the cross of green peel 'Qidong' and purple peel '8 guo' revealed that the purple to green color of eggplant peel is dominant and controlled by a pair of alleles. Bulked segregant analysis (BSA), SNP haplotyping, and fine genetic mapping delimited candidate genes to a 350 kb region of eggplant chromosome 10 flanked by markers KA2381 and CA8828. One ANS gene (EGP22363) was predicted to be a candidate gene based on gene annotation and sequence alignment of the 350-kb region. Sequence analysis revealed that a single base mutation of 'T' to 'C' on the exon green peel, which caused hydrophobicity to become hydrophilic serine, led to a change in the three-level spatial structure. Additionally, EGP22363 was more highly expressed in purple peels than in green peels. Collectively, EGP22363 is a strong candidate gene for anthocyanin biosynthesis in purple eggplant peels. These results provide important information for molecular marker-assisted selection in eggplants, and a basis for analyzing the regulatory pathways responsible for anthocyanin biosynthesis in eggplants. [ABSTRACT FROM AUTHOR]

Simple Summary: Leaves often turn red during senescence, providing us with a colorful life. Anthocyanin accumulation is the main cause of the coloration and its biosynthesis during leaf senescence is an important biological process, which might contain different mechanisms from other tissues. It is essential to understand the molecular mechanism of anthocyanin accumulation during leaf senescence, which would provide new insight into leaf coloration and molecular breeding for more colorful plants in spring or autumn. In this review, we focused on leaf coloration during senescence. We emphatically discussed several networks linked to genetic, hormonal, environmental, and nutritional factors in regulating anthocyanin accumulation during leaf senescence. This paper aims to provide a regulatory model for leaf coloration and to put forward some prospects for future studies. Leaf senescence is the last stage of leaf development, and it is accompanied by a leaf color change. In some species, anthocyanins are accumulated during leaf senescence, which are vital indicators for both ornamental and commercial value. Therefore, it is essential to understand the molecular mechanism of anthocyanin accumulation during leaf senescence, which would provide new insight into autumn coloration and molecular breeding for more colorful plants. Anthocyanin accumulation is a surprisingly complex process, and significant advances have been made in the past decades. In this review, we focused on leaf coloration during senescence. We emphatically discussed several networks linked to genetic, hormonal, environmental, and nutritional factors in regulating anthocyanin accumulation during leaf senescence. This paper aims to provide a regulatory model for leaf coloration and to put forward some prospects for future development. [ABSTRACT FROM AUTHOR]

Objective: Known for anti‐inflammatory and antioxidant properties, flavonoid has phytoestrogenic effects, but it is unclear whether its role in hyperuricemia and metabolic syndrome (MetS) differs by gender. Moreover, given the strong association between hyperuricemia and MetS, we aimed to explore whether flavonoid is a protective factor for hyperuricemia, independently of MetS, in different genders. Methods: Data for 2007–2010 and 2017–2018 were obtained from the National Health and Nutrition Examination Survey (NHANES) and the Food and Nutrient Database for Dietary Studies (FNDDS). To assess the association among flavonoid, hyperuricemia, and MetS, multivariate logistic regression and subgroup analyses were conducted. Besides, to investigate whether the association between flavonoid and hyperuricemia was independent of MetS, multivariate logistic regression models were further conducted to explore the association between flavonoid and MetS among females with hyperuricemia and to investigate the association between flavonoid and hyperuricemia among females after excluding MetS. Result: Among 5356 females, anthocyanin intake was inversely associated with the prevalence of hyperuricemia (Q4 vs. Q1: OR 0.49, 95% CI 0.31 to 0.76), and MetS (Q4 vs. Q1: OR 0.68, 95% CI 0.50 to 0.93). Furthermore, subgroup analyses showed the beneficial association between anthocyanin and hyperuricemia among females aged 40 to 59 years and menopausal. However, among 5104 males, no significant association was observed after adjustment for covariates (Q4 vs. Q1: OR 0.81, 95% CI 0.56 to 1.18). While in 372 females with hyperuricemia, no significant association was found between MetS and anthocyanin (Q4 vs. Q1: OR 0.88, 95% CI 0.31 to 2.49). Meanwhile, among 3335 females after excluding MetS, there was still a significant association between anthocyanin and a lower prevalence of hyperuricemia (Q4 vs. Q1: OR 0.38, 95% CI 0.17 to 0.85). Conclusion: Dietary anthocyanin is associated with a lower prevalence of hyperuricemia independently of MetS among females. Foods rich in anthocyanin should be emphasized for females, especially those aged 40 to 59 years and menopausal, which may be of potential significance in the prevention of hyperuricemia. [ABSTRACT FROM AUTHOR]

Cyanidin 3-O-glucoside (C3G) is believed to combine with oral mucin, thus impairing oral lubrication and leading to the development of oral astringency. When C3G is oxidized into cyanidin 3-O-glucoside quinone (C3GQ), it might covalently interact with cysteine of mucin to enhance astringency. Herein, their detailed interactions at the molecule level were characterized through spectroscopy, isothermal titration calorimetry and determination of free amino and sulfhydryl groups. The results showed that hydrogen bond and van der Waals force were the predominant non-covalent interactions. Furthermore, C3GQ could additionally bind to mucin by forming C-N and C-S bonds since the amino and sulfhydryl groups of mucin decreased by 0.48 mmol/g and 4.14 µmol/g after reacting with C3GQ. Besides, C3GQ had stronger interaction with mucin as the exothermic value of Muc-C3GQ (2513 KJ/mol) was larger than Muc-C3G (60.4 KJ/mol). These findings may explain the phenomenon of increased astringency of anthocyanins after being oxidized into quinones. [ABSTRACT FROM AUTHOR]

Cardiovascular disease (CVD) represents a substantial global health challenge, with its impact on mortality and morbidity rates surpassing that of cancer. The present study was designed to explore the cardioprotective properties of anthocyanin (ACN), a compound derived from black barley, against oxidative stress-induced damage in myocardial cells and to uncover the molecular mechanisms at play. Utilizing both in vitro and in vivo experimental models, our findings indicate that ACN notably reduced cell damage caused by oxidative stress and effectively prevented apoptosis. High-throughput RNA sequencing analysis has shed light on the mechanism by which ACN achieves its antioxidative stress effects, implicating the PTEN-Akt signaling pathway. ACN was found to modulate PTEN expression levels, which in turn influences the Akt pathway, leading to a reduction in apoptotic processes. This novel insight lays the groundwork for the potential clinical utilization of ACN in the management of CVD. While this study has shed light on some of the functions of ACN, it is important to recognize that natural compounds often interact with multiple molecular targets and engage in intricate signaling cascades. Future research endeavors will concentrate on further elucidating the regulatory mechanisms by which ACN influences PTEN expression, with the goal of enhancing our comprehension and expanding the therapeutic potential of ACN in the treatment of cardiovascular conditions. [ABSTRACT FROM AUTHOR]

Introduction: The biosynthesis of secondary metabolites like anthocyanins is often governed by metabolic gene clusters (MGCs) in the plant ancestral genome. However, the existence of gene clusters specifically regulating anthocyanin accumulation in certain organs is not well understood. Methods and results: In this study, we identify MGCs linked to the coloration of cotton reproductive organs, such as petals, spots, and fibers. Through genetic analysis and map-based cloning, we pinpointed key genes on chromosome A07, such as PCC/GhTT19, which is involved in anthocyanin transport, and GbBM and GhTT2-3A, which are associated with the regulation of anthocyanin and proanthocyanidin biosynthesis. Our results demonstrate the coordinated control of anthocyanin and proanthocyanidin pathways, highlighting the evolutionary significance of MGCs in plant adaptation. The conservation of these clusters in cotton chromosome A07 across species underscores their importance in reproductive development and color variation. Our study sheds light on the complex biosynthesis and transport mechanisms for plant pigments, emphasizing the role of transcription factors and transport proteins in pigment accumulation. Discussion: This research offers insights into the genetic basis of color variation in cotton reproductive organs and the potential of MGCs to enhance our comprehension of plant secondary metabolism. [ABSTRACT FROM AUTHOR]

Anthocyanins are precious industrial raw materials. Purple corn is rich in anthocyanins, with large variation in their content between organs. It is imperative to find a rapid and non-destructive method to determine the anthocyanin content in purple corn. To this end, a field experiment with ten purple corn hybrids was conducted, collecting plant images using a digital camera and determining the anthocyanin content of different organ types. The average values of red (R), green (G) and blue (B) in the images were extracted. The color indices derived from RGB arithmetic operations were applied in establishing a model for estimation of the anthocyanin content. The results showed that the specific color index varied with the organ type in purple corn, i.e., ACCR for the grains, BRT for the cobs, ACCB for the husks, R for the stems, ACCB for the sheaths and BRT for the laminae, respectively. Linear models of the relationship between the color indices and anthocyanin content for different organs were established with R2 falling in the range of 0.64–0.94. The predictive accuracy of the linear models, assessed according to the NRMSE, was validated using a sample size of 2:1. The average NRMSE value was 11.68% in the grains, 13.66% in the cobs, 8.90% in the husks, 27.20% in the stems, 7.90% in the sheaths and 15.83% in the laminae, respectively, all less than 30%, indicating that the accuracy and stability of the model was trustworthy and reliable. In conclusion, this study provided a new method for rapid, non-destructive prediction of anthocyanin-rich organs in purple corn. [ABSTRACT FROM AUTHOR]

Physalis philadelphica, a member of the Solanaceae family, commonly known as Physalis, is a one-year-old herbaceous plant with both medicinal and edible properties, as well as ornamental value. At present, only limited research is available on the flower color of P. philadelphica. This study aimed to elucidate the metabolic characteristics underlying the flower color of P. philadelphica and to identify key genes associated with flower color metabolism. We selected two representative varieties of P. philadelphica with significant differences in flower color, namely, "Tieba" (yellow flower) and "Qingjin" (yellow-purple flower), as the experimental materials. The analysis of related pigment components and the determination of relative content by high-performance liquid chromatography were conducted to investigate the flower color-related metabolic pathways of P. philadelphica. Through next-generation sequencing, these pathways were further investigated for the characteristics and differentially expressed genes (DEGs) associated with flower color formation. The results of the research show that: Anthocyanin is the main component of petal coloring of P. philadelphica var. Qingjin, while malvidin pigment, pelargonidin, delphinidin, and cyanidin are the main components of flower color intensity. Carotenoids are the main components of the petal coloring of P. philadelphica var. Tieba and β-carotene is the main component of flower color intensity. Comparing different developmental stages of these two kinds of Physalis pubescens, we identified two key transcription factors (TFs) (eBP and STAT) that were involved in the inhibition of anthocyanin synthesis and regulate the inhibition of pf05G124640 (dihydroflavonol 4-reductase) and pf09G224140 (anthocyanin synthase) in anthocyanin synthesis. One heat shock transcription factor was found to regulate the flavonoid and flavonol synthesis pathway of pf01G020090 (anthocyanin 3-O-glucosyltransferase); two key TFs (NAC and G2-Like), pf10G255070 (isoricin dehydrogenase) and pf09G237080 (abscisic acid 8′-hydroxylase), played important roles in carotene biosynthesis. This study provides new insights for further exploration of the genetic diversity of petal coloring in P. philadelphica and establishes a foundation for subsequent molecular breeding efforts. [ABSTRACT FROM AUTHOR]

Background: Purple non-heading Chinese cabbage [Brassica campestris (syn. Brassica rapa) ssp. chinensis] has become popular because of its richness in anthocyanin. However, anthocyanin only accumulates in the upper epidermis of leaves. Further studies are needed to investigate the molecular mechanisms underlying the specific accumulation of it. Results: In this study, we used the laser capture frozen section method (LCM) to divide purple (ZBC) and green (LBC) non-heading Chinese cabbage leaves into upper and lower epidermis parts (Pup represents the purple upper epidermis, Plow represents the purple lower epidermis, Gup represents the green upper epidermis, Glow represents the green lower epidermis). Through transcriptome sequencing, we found that the DIHYDROFLAVONOL 4-REDUCTASE-encoding gene BcDFR, is strongly expressed in Pup but hardly in others (Plow, Gup, Glow). Further, a deletion and insertion in the promoter of BcDFR in LBC were found, which may interfere with BcDFR expression. Subsequent analysis of gene structure and conserved structural domains showed that BcDFR is highly conserved in Brassica species. The predicted protein-protein interaction network of BcDFR suggests that it interacts with almost all functional proteins in the anthocyanin biosynthesis pathway. Finally, the results of the tobacco transient expression also demonstrated that BcDFR promotes the synthesis and accumulation of anthocyanin. Conclusions: BcDFR is specifically highly expressed on the upper epidermis of purple non-heading Chinese cabbage leaves and regulates anthocyanin biosynthesis and accumulation. Our study provides new insights into the functional analysis and transcriptional regulatory network of anthocyanin-related genes in purple non-heading Chinese cabbage. [ABSTRACT FROM AUTHOR]

Anthocyanins are ubiquitous pigments derived from the phenylpropanoid compound conferring red, purple and blue pigmentations to various organs of horticultural crops. The metabolism of flavonoids in the cytoplasm leads to the biosynthesis of anthocyanin, which is then conveyed to the vacuoles for storage by plant glutathione S-transferases (GST). Although GST is important for transporting anthocyanin in plants, its identification and characterization in eggplant (Solanum melongena L.) remains obscure. In this study, a total of 40 GST genes were obtained in the eggplant genome and classified into seven distinct chief groups based on the evolutionary relationship with Arabidopsis thaliana GST genes. The seven subgroups of eggplant GST genes (SmGST) comprise: dehydroascorbate reductase (DHAR), elongation factor 1Bγ (EF1Bγ), Zeta (Z), Theta(T), Phi(F), Tau(U) and tetra-chlorohydroquinone dehalogenase TCHQD. The 40 GST genes were unevenly distributed throughout the 10 eggplant chromosomes and were predominantly located in the cytoplasm. Structural gene analysis showed similarity in exons and introns within a GST subgroup. Six pairs of both tandem and segmental duplications have been identified, making them the primary factors contributing to the evolution of the SmGST. Light-related cis-regulatory elements were dominant, followed by stress-related and hormone-responsive elements. The syntenic analysis of orthologous genes indicated that eggplant, Arabidopsis and tomato (Solanum lycopersicum L.) counterpart genes seemed to be derived from a common ancestry. RNA-seq data analyses showed high expression of 13 SmGST genes with SmGSTF1 being glaringly upregulated on the peel of purple eggplant but showed no or low expression on eggplant varieties with green or white peel. Subsequently, SmGSTF1 had a strong positive correlation with anthocyanin content and with anthocyanin structural genes like SmUFGT (r = 0.9), SmANS (r = 0.85), SmF3H (r = 0.82) and SmCHI2 (r = 0.7). The suppression of SmGSTF1 through virus-induced gene silencing (VIGs) resulted in a decrease in anthocyanin on the infiltrated fruit surface. In a nutshell, results from this study established that SmGSTF1 has the potential of anthocyanin accumulation in eggplant peel and offers viable candidate genes for the improvement of purple eggplant. The comprehensive studies of the SmGST family genes provide the foundation for deciphering molecular investigations into the functional analysis of SmGST genes in eggplant. [ABSTRACT FROM AUTHOR]

The anthocyanin compound cyanidin 3-O-glucoside (C3G) is a natural pigment widely used in food and nutraceutical industries. Its microbial synthesis by E. coli is a promising alternative to the traditional extraction methods. However, part of the synthesized C3G accumulates in the cytoplasm, thus potentially causing growth inhibition and product degradation. Therefore, it is necessary to enhance C3G secretion via exploration of native transporters facilitating C3G export. In this study, we report the screening and verification of native multidrug resistance transporters from 40 candidates in E. coli that can improve the extracellular C3G production when using catechin as the substrate. Overexpression of single transporter genes including fsr, yebQ, ynfM, mdlAB, and emrKY were found to increase C3G production by 0.5-to 4.8-fold. Genetic studies indicated that mdlAB and emrKY are vital transporters in the secretion of C3G. Our study reveals a set of new multidrug resistance transporters for the improvement of microbial biosynthesis of C3G and other anthocyanins. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]