Anthocyanins Research Articles

Transcriptomic and metabolomic analysis of poplar response to feeding by Hyphantria cunea

Populus cathayana × canadansis ‘Xinlin 1’ (‘P.‘xin lin 1’) with the characteristics of rapid growth and high yield, is frequently attacked by herbivorous insects. However, little is known about how it defenses against Hyphantria cunea (H. cunea) at molecular and biochemical levels. Differences in the transcriptome and metabolome were analyzed after ‘P. ‘xin lin 1’ leaves were fed to H. cunea for 0h, 2h, 4h, 8h, 16h and 24h. In the five comparison groups including 2h vs. CK, 4h vs. CK, 8h vs. CK, 16h vs. CK, and 24h vs. CK, a total of 8925 genes and 842 metabolites were differentially expressed. A total of 825 transcription factors (TFs) were identified, which encoded 56 TF families. The results showed that the top four families with the highest number of TFs were AP2/ERF, MYB, C2C2, bHLH. Analyses of leaves which were fed to H. cunea showed that the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were significantly enriched in plant hormone signal transduction pathway, MAPK signaling pathway, flavonoid, flavone and flavonol and anthocyanin biosynthesis pathway. Additionally, there were a number of genes significantly up-regulated in MAPK signaling pathway. Some compounds involved in plant hormone signal transduction and flavonoid/flavone and flavonol/ anthocyanin pathways such as jasmonic acid (JA), jasmonoyl-L-Isoleucine (JA-Ile), kaempferol and cyanidin-3-O-glucoside were induced in infested ‘P.‘xin lin 1’. This study provides a new understanding for exploring the dynamic response mechanism of poplar to the infestation of H. cunea.

Study on preparation of “ping-pong” shaped chitosan oligosaccharide -based hollow mesoporous carbon as a carrier for efficient anthocyanin loading

Carriers for efficient loading and delivery of compounds are urgently needed. A multifunctional nanoplatform of ordered hollow mesoporous carbon (HMC) was developed to load anthocyanins (AN) efficiently. The morphology, specific surface area, binding mode, and biocompatibility of HMC were verified. HMCs were uniformly spherical with well-defined cavities and mesoporous shells, similar to a “ping-pong” ball shape, and this shape of HMC provided a more spatial location for the load of the AN. And the best loading result of AN was 33.39 % ± 3.00 %. Coarse-grained molecular dynamics (CGMD) simulations showed that HMC and AN may bind by electrostatic interaction and hydrogen bonding, the binding process indicated that HMC contributed to the loading of AN, and the cytotoxicity results showed no significant toxicity of the complex. The homogeneous morphology and good biocompatibility of HMC offer new probabilities for the high effectiveness of oral delivery of active substances.

Texture, swallowing and digestibility characteristics of a low-GI dysphagia food as affected by addition of dietary fiber and anthocyanins

Dysphagia is a common problem in the elderly population, thus texture modifications in foods suitable for dysphagic patients aroused a lot of interest. In the study, low glycemic index (GI) dysphagia foods were designed with adding dietary fiber (DF) and anthocyanins (AS), and their in vitro enzymatic digestion and predicted GI values were investigated by first-order kinetic model and slope log model. Results showed that all samples belonged to dysphagia foods at level 4 (pureed) in the International Dysphagia Diet Standardization Initiative (IDDSI) framework, and exhibited shear thinning behavior. AS reduced the apparent viscosity and storage modulus, increased redness, while DF decreased the hardness and gumminess of dysphagia food masses. DF and AS significantly increased the slowly digestible starch and resistant starch content in food system. With the increased addition of 5 % DF and 3 % AS, the predicted GI value of dysphagia food masses could be decreased to 51.08 ± 2.48, which belonged to the low-GI food, and showed the best water holding capacity and the highest total sensory evaluation score. In addition, a strong correlation was also found between the slow digestion indicators, rheological properties and swallowing ease. This study provides a theoretical foundation for the design of dysphagia food products with slow digestibility and low GI values.

Construction of Anthocyanin Biosynthesis System Using Chalcone as a Substrate in Lactococcus lactis NZ9000.

Anthocyanins are high-value natural compounds, but to date, their production still mainly relies on extraction from plants. A five-step metabolic pathway was constructed in probiotic Lactococcus lactis NZ9000 for rapid, stable, and glycosylated anthocyanin biosynthesis using chalcone as a substrate. The genes were cloned from anthocyanin-rich blueberry: chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanin synthase (ANS), and UDPG-flavonoid 3-O-glycosyltransferase (3GT). Using HR, the polysaccharide pellicle (PSP) segment of the cell wall polysaccharide synthesis (cwps) gene cluster from L. lactis NZ9000 was cloned into vector p15A-Cm-repDE. Then, CHI and F3H were placed sequentially under the control of NZProm 3 of this gene cluster in the vector, which was transformed into L. lactis NZ9000 to obtain Strain A. Furthermore, Strain B was constructed by placing F3H-DFR-ANS and 3GT under NZProm 2 and 3, respectively. Using LC-MS/MS analysis, several types of anthocyanins, including callistephin chloride, oenin chloride, malvidin O-hexoside, malvidin 3,5-diglucoside, and pelargonidin 3-O-malonyl-malonylhexoside, increased in the supernatant of the co-culture of Strains A and B compared to that of L. lactis NZ9000. This is the first time that a five-step metabolic pathway has been developed for anthocyanin biosynthesis in probiotic L. lactis NZ9000. This work lays the groundwork for novel anthocyanin production by a process involving the placement of several biosynthesis genes under the control of a gene cluster.

Inducible overexpression of MYB118-like gene improves anthocyanin production in Populus × canescens

Anthocyanins are secondary metabolites which contribute different colors to the leaves. Anthocyanin biosynthesis is regulated by MYB transcription factors, which have been extensively studied and characterized in a diversity of plants. In this study, we identified a novel MYB transcription factor MYB118L, from Populus 'Zhonghua Hongye', which showed an elevated accumulation of anthocyanin than Populus clone ZL-2025. Subcellular localization analyses revealed that MYB118L-GFP fusion protein was specifically located in the nucleus. Transgenic plants overexpressing MYB118L driven by the stress-inducible Rd29A promoter showed a significant increase in anthocyanin production, resulting in a red coloration of the leaves under drought stress conditions. These plants also exhibited higher expression levels of genes involved in anthocyanin biosynthesis compared to the wild type, suggesting that MYB118L positively regulates the expression of these genes. Y1H and dual-luciferase assays confirmed that MYB118L can directly activate the promoters of LAR1 gene. Our findings suggest that MYB118L is an essential transcription factor involved in the regulation of anthocyanin biosynthesis in poplar and could be utilized for genetic engineering of colorful tree species.

Polysaccharide-potato protein coacervates for enhanced anthocyanin bioavailability and stability

Anthocyanins (ACNs) possess strong antioxidants, anti-cancer, anti-obesity, anti-diabetic, and anti-inflammatory properties but are limited use by their susceptibility to environmental factors. This study aims to overcome these limitations by developing and assessing a novel coacervate system, consisting of potato protein isolate (PPI) combined with various polysaccharides, to stabilize and encapsulate anthocyanins from black carrot concentrate The polysaccharides included in this system include inulin, gum Arabic, guar gum, pectin, and soluble fiber. The coacervate system's effectiveness in maintaining stability and increasing the bioavailability of anthocyanins was evaluated compared to conventional soybean protein-based systems. The results show that pH considerably influences potato protein solubility, with maximum solubility at strongly acidic (pH 2) conditions. Hygroscopicity and moisture content analysis of the coacervates showed significant variations, with potato protein-guar gum (PPIGG) microcapsules having the lowest moisture content and potato protein gum Arabic (PPIGA) microcapsules having the highest moisture content. SEM imaging illustrated distinct microcapsule morphologies, while FT-IR measurement verified the successful integration of proteins and polysaccharides. The significance of the research reflects its proof that potato protein isolate (PPI) based coacervate systems consists of potato protein with polysaccharides, particularly those containing gum Arabic and pectin, have significant potential for improving anthocyanin stability and bioavailability. These findings guide future studies to investigate other polysaccharides, improve coacervation processes, and explore applications in the food and nutraceutical sectors. It also offers valuable insights for creating efficient encapsulation techniques for bioactive substances.

The identification and analysis of meristematic mutations within the apple tree that developed the RubyMac sport mutation

BackgroundUnderstanding the molecular basis of sport mutations in fruit trees has the potential to accelerate generation of improved cultivars.ResultsFor this, we analyzed the genome of the apple tree that developed the RubyMac phenotype through a sport mutation that led to the characteristic fruit coloring of this variety. Overall, we found 46 somatic mutations that distinguished the mutant and wild-type branches of the tree. In addition, we found 54 somatic gene conversions (i.e., loss-of-heterozygosity mutations) that also distinguished the two parts of the tree. Approximately 20% of the mutations were specific to individual cell lineages, suggesting that they originated from the corresponding meristematic layers. Interestingly, the de novo mutations were enriched for GC = > AT transitions while the gene conversions showed the opposite bias for AT = > GC transitions, suggesting that GC-biased gene conversions have the potential to counteract the AT-bias of de novo mutations. By comparing the gene expression patterns in fruit skins from mutant and wild-type branches, we found 56 differentially expressed genes including 18 involved in anthocyanin biosynthesis. While none of the differently expressed genes harbored a somatic mutation, we found that some of them in regions of the genome that were recently associated with natural variation in fruit coloration.ConclusionOur analysis revealed insights in the characteristics of somatic change, which not only included de novo mutations but also gene conversions. Some of these somatic changes displayed strong candidate mutations for the change in fruit coloration in RubyMac.

Transcriptome analysis reveals biosynthesis and regulation of flavonoid in common bean seeds during grain filling

The Andean domesticated common beans (Phaseolus vulgaris) are significant sources of phenolic compounds associated with health benefits. However, the regulation of biosynthesis of these compounds during bean seed development remains unclear. To elucidate the gene expression patterns involved in the regulation of the flavonoid pathway, we conducted a transcriptome analysis of two contrasting Chilean varieties, Negro Argel (black bean) and Coscorron (white bean), at three developmental stages associated with seed color change, as well as different flavonoid compound accumulations. Our study reveals that phenolic compound synthesis initiates during seed filling, although it exhibits desynchronization between both varieties. We identified 10,153 Differentially Expressed Genes (DEGs) across all comparisons. The KEGG pathway ‘Flavonoid biosynthesis’ showed enrichment of induced DEGs in Negro Argel (PV172), consistent with the accumulation of delphinidin, petunidin, and malvidin hexosides in their seeds, while catechin glucoside, procyanidin and kaempferol derivatives were predominantly detected in Coscorrón (PV24). Furthermore, while the flavonoid pathway was active in both varieties, our results suggest that enzymes involved in the final steps, such as ANS and UGT, were crucial, inducing anthocyanin formation in Negro Argel. Additionally, during active anthocyanin biosynthesis, the accumulation of reserve proteins or those related to seed protection and germination was induced. These findings provide valuable insights and serve as a guide for plant breeding aimed at enhancing the health and nutritional properties of common beans.

Metabolite concentrations and the expression profiles of the corresponding metabolic pathway genes in eggplant (Solanum melongena L.) fruits of contrasting colors.

Eggplant (Solanum melongena L.) ranks fifth in importance among vegetable crops of the Solanaceae family, in part due to the high antioxidant properties and polyphenol content of the fruit. Along with the popular purple-fruited varieties of S. melongena, there are cultivars, the fruits of which are rich in phenolic compounds, but are white-colored due to the lack of anthocyanin biosynthesis. Determination of the amount of anthocyanins and other phenolic compounds, as well as carotenoids and sugars, is included in the assessment of the quality of eggplant fruits of commercial (technical) ripeness. In addition to antioxidant and taste properties, these metabolites are associated with fruit resistance to various stress factors. In this study, a comparative analysis of the content of anthocyanins, carotenoids and soluble sugars (sucrose, glucose, fructose) in the peel and pulp of the fruit of both technical and biological ripeness was carried out in purple-fruited (cv. Vlas) and white-fruited (cv. Snezhny) eggplant accessions of domestic selection. The peel and pulp of biologically ripe fruits of the cvs Vlas and Snezhny were used for comparative transcriptomic analysis. The key genes of the flavonoid and carotenoid metabolism, sucrose hydrolysis, and soluble sugar transport were shown to be differentially expressed between fruit tissues, both within each cultivar and between them. It has been confirmed that the purple color of the peel of the cv. Vlas fruit is due to substantial amounts of anthocyanins. Flavonoid biosynthesis genes showed a significantly lower expression level in the ripe fruit of the cv. Vlas in comparison with the cv. Snezhny. However, in both cultivars, transcripts of anthocyanin biosynthesis genes (DFR, ANS, UFGT) were not detected. Additionally, the purple fruit of the cv. Vlas accumulated more carotenoids and sucrose and less glucose and fructose than the white fruit of the cv. Snezhny. Biochemical data corresponded to the differential expression pattern of the key genes encoding the structural proteins of metabolism and transport of the compounds analyzed.

The NAC activator, MdNAC77L, regulates anthocyanin accumulation in red flesh apple

Anthocyanin is widely acknowledged as a crucial component contributing to apple fruit quality. However, research on the influence of NAC transcription factors on anthocyanin accumulation in red flesh apple is limited. In this study, a NAC transcription factor MdNAC77L was identified as highly related to the change of anthocyanin content, based on a combined anthocyanin metabolome and transcriptome analysis. Overexpression of MdNAC77L significantly increased the accumulation of anthocyanin in both apple and strawberry fruits, along with the expression of several anthocyanin-related enzymes. Molecular-level analyses demonstrated that MdNAC77L was directly combined with the promoters of three pivotal enzymes (dihydroflavonol 4-reductase, anthocyanin synthase, and UDP-flavonoid glucosyltransferase) of anthocyanin biosynthetic pathway. We found that ABA strongly induced the expression of MdNAC77L, which activated the expression of three downstream target genes. In addition, MdNAC77L showed higher transcript accumulation in flesh with lower anthocyanin content than that in red peel. We revealed the new core factor, MdNAC77L, involved in anthocyanin accumulation in apple red flesh. This research provides a fresh perspective on the intricate regulatory mechanisms governing anthocyanin biosynthesis in red-fleshed apples.

Enhanced performance of dye-sensitized solar cells via anthocyanin, chlorophyll, benzothiadiazole and diphenylacridine co-sensitizers and amine-based co-adsorbents

Anthocyanin (ANT) and chlorophyll (CHL) natural dyes extracted from blue butterfly pea flowers and spinach leaves and two synthetic metal-free dyes (BIM33 and C1) were evaluated as sensitizers/co-sensitizers in dye-sensitized solar cells (DSSCs). To suppress the possible dye aggregation, triethylamine (TEA) and diethylenetriamine (DETA) were utilized as alternative co-adsorbents to the commonly used chenodeoxycholic acid (CDCA). Furthermore, CHL, BIM33, and C1 were co-sensitized with ANT to achieve panchromatic light absorption and, hence, enhance the photovoltaic performance. Therefore, the power conversion efficiencies (PCEs) of DSSCs based on the dyes were significantly improved from 1.19–5.01 % to 2.39–6.31 % by the co-sensitization and utilization of co-adsorbents. Meanwhile, the efficiencies of DSSCs based on TEA or DETA were superior to those based on CDCA under the same conditions. This study provides effective strategies for improving the performance of DSSCs based on environment-friendly dyes.

Genome-Wide Identification and Expression Analysis of GST Genes during Light-Induced Anthocyanin Biosynthesis in Mango (Mangifera indica L.).

Anthocyanins are important secondary metabolites contributing to the red coloration of fruits, the biosynthesis of which is significantly affected by light. Glutathione S-transferases (GSTs) play critical roles in the transport of anthocyanins from the cytosol to the vacuole. Despite their importance, GST genes in mango have not been extensively characterized. In this study, 62 mango GST genes were identified and further divided into six subfamilies. MiGSTs displayed high similarity in their exon/intron structure and motif and domain composition within the same subfamilies. The mango genome harbored eleven pairs of segmental gene duplications and ten sets of tandemly duplicated genes. Orthologous analysis identified twenty-nine, seven, thirty-four, and nineteen pairs of orthologous genes among mango MiGST genes and their counterparts in Arabidopsis, rice, citrus, and bayberry, respectively. Tissue-specific expression profiling highlighted tissue-specific expression patterns for MiGST genes. RNA-seq and qPCR analyses revealed elevated expression levels of seven MiGSTs including MiDHAR1, MiGSTU7, MiGSTU13, MiGSTU21, MiGSTF3, MiGSTF8, and MiGSTF9 during light-induced anthocyanin accumulation in mango. This study establishes a comprehensive genetic framework of MiGSTs in mango fruit and their potential roles in regulating anthocyanin accumulation, which is helpful in developing GST-derived molecular markers and speeding up the process of breeding new red-colored mango cultivars.

Transcriptomic and Metabolomic Profiling of Root Tissue in Drought-Tolerant and Drought-Susceptible Wheat Genotypes in Response to Water Stress.

Wheat is the most widely grown crop in the world; its production is severely disrupted by increasing water deficit. Plant roots play a crucial role in the uptake of water and perception and transduction of water deficit signals. In the past decade, the mechanisms of drought tolerance have been frequently reported; however, the transcriptome and metabolome regulatory network of root responses to water stress has not been fully understood in wheat. In this study, the global transcriptomic and metabolomics profiles were employed to investigate the mechanisms of roots responding to water stresses using the drought-tolerant (DT) and drought-susceptible (DS) wheat genotypes. The results showed that compared with the control group, wheat roots exposed to polyethylene glycol (PEG) had 25941 differentially expressed genes (DEGs) and more upregulated genes were found in DT (8610) than DS (7141). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs of the drought-tolerant genotype were preferably enriched in the flavonoid biosynthetic process, anthocyanin biosynthesis and suberin biosynthesis. The integrated analysis of the transcriptome and metabolome showed that in DT, the KEGG pathways, including flavonoid biosynthesis and arginine and proline metabolism, were shared by differentially accumulated metabolites (DAMs) and DEGs at 6 h after treatment (HAT) and pathways including alanine, aspartate, glutamate metabolism and carbon metabolism were shared at 48 HAT, while in DS, the KEGG pathways shared by DAMs and DEGs only included arginine and proline metabolism at 6 HAT and the biosynthesis of amino acids at 48 HAT. Our results suggest that the drought-tolerant genotype may relieve the drought stress by producing more ROS scavengers, osmoprotectants, energy and larger roots. Interestingly, hormone signaling plays an important role in promoting the development of larger roots and a higher capability to absorb and transport water in drought-tolerant genotypes.

Role of anthocyanin metabolic diversity in bract coloration of Curcuma alismatifolia varieties

Anthocyanins are one of the key metabolites influencing the coloration of ornamental bracts in plants. Curcuma alismatifolia is an emerging ornamental plant, known for the rich diversity in the coloration of its bracts and the variety of anthocyanins present. However, the specific anthocyanin metabolites contributing to this diversity are not entirely clear. This study examines the bract color variation across 19 C. alismatifolia varieties using colorimetric analysis and spectrophotometric determination of total anthocyanin content. The 19 accessions were categorized into four color groups: white, light pink, pink, and purple. Further analysis using anthocyanin metabolomics and transcriptomics was conducted on five C. alismatifolia varieties with significant differences in coloration and total anthocyanin content. In addition to previously reported anthocyanins, delphinidin-3-O-glucoside and peonidin-3-O-rutinoside were identified for the first time as important contributors to the diverse bract coloration in C. alismatifolia. Fifty-three differentially expressed genes (DEGs) were identified in the anthocyanin biosynthesis pathway, and two significant gene modules were determined through WGCNA analysis. Correlation network analysis revealed two BZ1 genes that may be key terminal enzyme genes affecting anthocyanin synthesis in C. alismatifolia bracts. Multiple transcription factors, including MYB, NAC, WRKY, ERF, and bHLH, may be involved in regulating the accumulation of different anthocyanin contents in the bracts. This research sheds light on the genetic and metabolic factors that influence bract coloration in C. alismatifolia.

Enhancing Red Table Grape Coloration Using Tsikoudia: A Novel and Sustainable Approach.

Achieving optimal coloration in red table grapes, especially in warm-climate regions, presents significant challenges due to high temperatures that inhibit anthocyanin biosynthesis. Conventional methods to enhance grape coloration, including the use of abscisic acid (ABA), ethephon, foliar nutrient supplementation, and viticultural practices like cluster trimming and girdling, have limitations related to cost, regulatory restrictions, and potential adverse effects on grapes quality. This study proposes the application of tsikoudia, a traditional Greek alcoholic beverage, as a novel, sustainable, and cost-effective alternative to conventional practices. Tsikoudia, applied during the veraison stage, significantly improved the coloration of 'Crimson Seedless' and 'Red Globe' grapes by enhancing anthocyanin accumulation and altering color parameters. Specifically, lightness (L*), chroma (C*), and hue angle (h), measured using the CIE-Lab color system, were reduced, while the Color Index for Red Grapes (CIRG) was increased. Additionally, total anthocyanin content, determined through spectrophotometric analysis, also showed an increase. These changes indicate a more intense red coloration. This research highlights the effectiveness of tsikoudia in improving grape coloration and contributes to the development of more sustainable viticultural practices.

Multi-omics analysis reveals anthocyanin synthesis is associated with drought stress tolerance in Chaenomeles speciosa flowers

Drought is one of the most severe abiotic stresses that limit plant growth. Chaenomeles speciosa, a Rosaceae plant of high ornamental value, exhibits noticeable changes in petal color under drought conditions. A multi-omics joint analysis was employed to examine the mechanism of flower color changes under drought conditions. We detected that the main reason for the change in flower color is the synthesis of anthocyanins, while ethylene (ET) and abscisic acid (ABA) also significantly increase. While ET and ABA are known to promote anthocyanin synthesis, their coordinated regulation under drought conditions remains unclear. This study aims to validate the hypothesis that ET/ABA mediated responses to drought regulate anthocyanin synthesis. The study inferred that the CsERF2, CsbZIP24–CsMYB6 signaling module plays a crucial role in the precise and dynamic regulation of anthocyanin synthesis. Yeast heterologous expression is used to demonstrate the drought tolerance function of candidate genes. Also, we performed transient expression analysis in petals suggests that these genes significantly contribute to anthocyanin accumulation under drought conditions. Moreover, Yeast one-hybrid and dual luciferase assays indicated that CsERF2 and CsbZIP24 can directly activate the expression of CsMYB6. Yeast two-hybrid, bimolecular fluorescence complementation, and Split-luciferase assays revealed interactions between CsERF2 and CsbZIP24 proteins, promoting anthocyanin biosynthesis. The study proposes a regulatory model for the mechanism of flower color change and aimed at exploring drought resistant ornamental plants and achieving their sustainable development.

Integrated Phenotypic Physiology and Transcriptome Analysis Revealed the Molecular Genetic Basis of Anthocyanin Accumulation in Purple Pak-Choi

Purple Pak-choi is rich in anthocyanins, which have both ornamental and edible health functions, and has been used more and more widely in facility cultivation. In order to further clarify the molecular mechanism of purple Pak-choi, two Pak-choi inbred lines (‘PQC’ and ‘HYYTC’) were selected for the determination of pigment content and transcriptome analysis, and the key genes controlling the formation of purple character in leaves of Pak-choi were discovered. The results of pigment determination showed that the anthocyanin content of ‘PQC’ was 0.29 mg/g, which was about 100 times than ‘HYYTC’; The chlorophyll content of ‘HYYTC’ was 2.25 mg/g, while ‘PQC’ only contained 1.05 mg/g. A total of 20 structural genes related to anthocyanin biosynthesis and 28 transcriptional regulatory genes were identified by transcriptome analysis. Weighted gene co-expression network analysis (WGCNA) was used to construct the weight network analysis map of 14 genes. The results showed that the cinnamate hydroxylase gene (BraA04002213, BrC4H3), flavanone-3- hydroxylase (BraA09004531, BrF3H1), and chalcone synthetase (BraA10002265, BrCHS1) were the core genes involved in the anthocyanin synthesis pathway of purple Pak-choi. The results identified the key genes controlling the formation of purple leaf traits, which laid a foundation for further analysis of the molecular mechanism of anthocyanin accumulation in purple Pak-choi and provided a theoretical basis for leaf color regulation.

Comprehensive, Genome-Wide Identification and Expression Analyses of Phenylalanine Ammonia-Lyase Family under Abiotic Stresses in Brassica oleracea.

Phenylalanine ammonia-lyase (PAL) acts as the rate-limiting enzyme for anthocyanin biosynthesis through the phenylpropanoid pathway, a crucial component of plant secondary metabolism. The PAL gene family plays a crucial role in plants' defense and stress responses, but its in silico identification and expression analyses in Brassica oleracea under different abiotic stresses remain unexplored. In this study, nine BolPAL, seven BrPAL, four AtPAL, and seventeen BnPAL genes were obtained from the genomes of B. oleracea, Brassica rapa, Arabidopsis thaliana, and Brassica napus, respectively. Segmental duplication and purifying selection are the causes of the BolPAL gene's amplification and evolution. The BolPAL genes with comparable intron-exon architectures and motifs were grouped together in the same clade. Three categories comprised the cis-regulatory elements: abiotic stressors, phytohormones, and light. According to the results of the qRT-PCR experiments, the majority of the BolPAL genes were expressed highly under MeJA, a low temperature, and a high temperature, and they were downregulated under ABA. Under white light (100 µmol m-2 s-1) with 50, 100, or 150 µmol m-2 s-1 far-red (FR), only a small number of the PAL genes were expressed at 50 and 100 µmol m-2 s-1 FR, while the majority of the PAL genes were slightly elevated at 150 µmol m-2 s-1 FR. This work offers a theoretical foundation for molecular breeding research to investigate the role of BolPAL genes and their role in anthocyanin biosynthesis.

BZIP Transcription Factor PavbZIP6 Regulates Anthocyanin Accumulation by Increasing Abscisic Acid in Sweet Cherry.

Basic leucine zipper (bZIP) transcription factors (TFs) play a crucial role in anthocyanin accumulation in plants. In addition to bZIP TFs, abscisic acid (ABA) increases anthocyanin biosynthesis. Therefore, this study aimed to investigate whether bZIP TFs are involved in ABA-induced anthocyanin accumulation in sweet cherry and elucidate the underlying molecular mechanisms. Specifically, the BLAST method was used to identify bZIP genes in sweet cherry. Additionally, we examined the expression of ABA- and anthocyanin-related genes in sweet cherry following the overexpression or knockdown of a bZIP candidate gene. In total, we identified 54 bZIP-encoding genes in the sweet cherry genome. Basic leucine zipper 6 (bZIP6) showed significantly increased expression, along with increased anthocyanin accumulation in sweet cherry. Additionally, yeast one-hybrid and dual-luciferase assays indicated that PavbZIP6 enhanced the expression of anthocyanin biosynthetic genes (PavDFR, PavANS, and PavUFGT), thereby increasing anthocyanin accumulation. Moreover, PavbZIP6 interacted directly with the PavBBX6 promoter, thereby regulating PavNCED1 to promote abscisic acid (ABA) synthesis and enhance anthocyanin accumulation in sweet cherry fruit. Conclusively, this study reveals a novel mechanism by which PavbZIP6 mediates anthocyanin biosynthesis in response to ABA and contributes to our understanding of the mechanism of bZIP genes in the regulation of anthocyanin biosynthesis in sweet cherry.

Biosynthesis and Extraction of Chlorophyll, Carotenoids, Anthocyanins, and Betalaine In Vivo and In Vitro.

As natural bioactive compounds, plant pigments play crucial roles not only in plant phenotype, growth, development, and adaptation to stress but also hold unique value in biotechnology, healthcare, and industrial applications. There is growing interest in the biosynthesis and acquisition of plant pigments. Thus, this paper explores emerging extraction methods of natural pigments and elucidates the biosynthesis pathways of four key plant pigments, chlorophylls, carotenoids, anthocyanins, and betalaine in vivo and in vitro. We comprehensively discuss the application of solvent, supercritical fluid [extraction], ultrasonic, and microwave-assisted extraction techniques, as well as introducing key enzymes, precursors, and synthetic pathways involved in pigment synthesis. δ-Aminolevulinic acid represents a pivotal initiating enzyme for chlorophyll synthesis, whereas isopentenylpyrophosphate, (IPP) and dimethylallyl pyrophosphate, (DMAPP) are closely associated with carotenoid biosynthesis. Phenylalanine and tyrosine are critical substances for anthocyanin and betalaine synthesis, respectively. Hence, crucial genes such as chlI, crtB, PGT8, CYP76AD1, and BvDODA can be employed for heterologous biosynthesis in vitro to meet the demand for increased plant pigment amount. As a pivotal determinant of plant coloration, an in-depth exploration into the high-quality acquisition of plant pigments can provide a basis for developing superior pigments and offer new insights into increasing pigment yield.