Identification of a Strong Anthocyanin Activator, VbMYBA, From Berries of Vaccinium bracteatum Thunb.

Wufanshu (Vaccinium bracteatum Thunb.), which is a wild member of the genus Vaccinium, accumulates high concentration of anthocyanin in its berries. In this study, the accumulated anthocyanins and their derivatives in Wufanshu berries were identified through UHPLC–MS/MS analysis. Candidate anthocyanin biosynthetic genes were identified from the transcriptome of Wufanshu berries. qRT-PCR analyses showed that the expression of anthocyanin structural genes correlated with anthocyanin accumulation in berries. The R2R3-MYB, VbMYBA, which is a homolog of anthocyanin promoting R2R3-MYBs from other Vaccinium species, was also identified. Transient expression of VbMYBA in Nicotiana tabacum leaves confirmed its role as an anthocyanin regulator, and produced a higher anthocyanin concentration when compared with blueberry VcMYBA expression. Dual-luciferase assays further showed that VbMYBA can activate the DFR and UFGT promoters from other Vaccinium species. VbMYBA has an additional 23 aa at the N terminus compared with blueberry VcMYBA, but this was shown not to affect the ability to regulate anthocyanins. Taken together, our results provide important information on the molecular mechanisms responsible for the high anthocyanin content in Wufanshu berries.

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Transcriptomic Profiling of Apple Calli With a Focus on the Key Genes for ALA-Induced Anthocyanin Accumulation

Frontiers in Plant Science ◽

10.3389/fpls.2021.640606 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jie Zheng ◽

Longbo Liu ◽

Huihui Tao ◽

Yuyan An ◽

Liangju Wang

Keyword(s):

Molecular Mechanisms ◽

Aminolevulinic Acid ◽

Anthocyanin Biosynthesis ◽

Transcript Level ◽

Flavonoid Biosynthesis ◽

Anthocyanin Accumulation ◽

Structural Genes ◽

Metabolism Regulation ◽

Positive Regulators ◽

R2r3 Myb

The red color is an attractive trait of fruit and determines its market acceptance. 5-Aminolevulinic acid (ALA), an eco-friendly plant growth regulator, has played a universal role in plant secondary metabolism regulation, particularly in flavonoid biosynthesis. It has been widely reported that ALA can up-regulate expression levels of several structural genes related to flavonoid metabolism and anthocyanin accumulation. However, the molecular mechanisms behind ALA-induced expression of these genes are complicated and still far from being completely understood. In this study, transcriptome analysis identified the differentially expressed genes (DEGs) associated with ALA-induced anthocyanin accumulation. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the flavonoid biosynthesis (ko00941) pathway was significantly enhanced in the ALA-treated apple calli at 24, 48, and 72 h after the treatment. Expression pattern revealed that ALA up-regulated the expression of the structural genes related to not only anthocyanin biosynthesis (MdCHS, MdCHI, MdF3’H, MdDFR, MdANS, and MdUFGT) but also anthocyanin transport (MdGST and MdMATE). Two R2R3-MYB transcription factors (MdMYB10 and MdMYB9), which are the known positive regulators of anthocyanin biosynthesis, were significantly induced by ALA. Gene overexpression and RNA interference assays demonstrated that MdMYB10 and MdMYB9 were involved in ALA-induced anthocyanin biosynthesis. Moreover, MdMYB10 and MdMYB9 might positively regulate the transcription of MdMATE8 by binding to the promoter region. These results indicate that MdMYB10 and MdMYB9 modulated structural gene expression of anthocyanin biosynthesis and transport in response to ALA-mediated apple calli coloration at the transcript level. We herein provide new details regarding transcriptional regulation of ALA-induced color development.

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CsMYB3 and CsRuby1 form an ‘Activator-and-Repressor’ Loop for the Regulation of Anthocyanin Biosynthesis in Citrus

Plant and Cell Physiology ◽

10.1093/pcp/pcz198 ◽

2019 ◽

Vol 61 (2) ◽

pp. 318-330 ◽

Cited By ~ 7

Author(s):

Ding Huang ◽

Zhouzhou Tang ◽

Jialing Fu ◽

Yue Yuan ◽

Xiuxin Deng ◽

...

Keyword(s):

Transcription Factor ◽

Anthocyanin Biosynthesis ◽

Myb Transcription Factor ◽

Nitrogen Stress ◽

Loop Model ◽

Anthocyanin Accumulation ◽

Promoter Activation ◽

R2r3 Myb ◽

Activation Capacity ◽

Anthocyanin Biosynthetic Genes

Abstract Anthocyanins are preferentially accumulated in certain tissues of particular species of citrus. A R2R3-MYB transcription factor (named Ruby1) has been well documented as an activator of citrus anthocyanin biosynthesis. In this study, we characterized CsMYB3, a transcriptional repressor that regulates anthocyanin biosynthesis in citrus. CsMYB3 was expressed in anthocyanin-pigmented tissues, and the expression was closely associated with that of Ruby1, which is a key anthocyanin activator. Overexpression of CsMYB3 in Arabidopsis resulted in a decrease in anthocyanins under nitrogen stress. Overexpression of CsMYB3 in the background of CsRuby1-overexpressing strawberry and Arabidopsis reduced the anthocyanin accumulation level. Transient promoter activation assays revealed that CsMYB3 could repress the activation capacity of the complex formed by CsRuby1/CsbHLH1 for the anthocyanin biosynthetic genes. Moreover, CsMYB3 could be transcriptionally activated by CsRuby1 via promoter binding, thus forming an ‘activator-and-repressor’ loop to regulate anthocyanin biosynthesis in citrus. This study shows that CsMYB3 plays a repressor role in the regulation of anthocyanin biosynthesis and proposes an ‘activator-and-repressor’ loop model constituted by CsRuby1 and CsMYB3 in the regulation of anthocyanin biosynthesis in citrus.

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Pericarp Pigmentation Correlates with Hormones and Intensifies with Continuation of Bud Sport Generations from ‘Red Delicious’

10.1101/336263 ◽

2018 ◽

Author(s):

Wen-Fang Li ◽

Juan Mao ◽

Shi-Jin Yang ◽

Zhi-Gang Guo ◽

Zong-Huan Ma ◽

...

Keyword(s):

Molecular Level ◽

Anthocyanin Synthesis ◽

Anthocyanin Content ◽

Biosynthesis Pathway ◽

Anthocyanin Accumulation ◽

Structural Genes ◽

Bud Sport ◽

Phenylpropanoid Biosynthesis ◽

Highly Correlated ◽

Flavonoid Biosynthesis Pathway

ABSTRACTBud sport mutants of apple (Malus domestica Borkh.) trees with a highly blushed colouring pattern are mainly caused by the accumulation of anthocyanins in the pericarp. Hormones are important factors modulating anthocyanin accumulation. However, a good understanding of the interplay between hormones and anthocyanin synthesis in apples, especially in mutants at the molecular level, remains elusive. Here, physiological and comparative transcriptome approaches were used to reveal the molecular basis of pericarp pigmentation in ‘Red Delicious’ and its mutants, including ‘Starking Red’, ‘Starkrimson’, ‘Campbell Redchief’ and ‘Vallee spur’, which were designated G0 to G4, respectively. Pericarp pigmentation gradually proliferated from G0 to G4. The anthocyanin content was higher in the mutants than in ‘Red Delicious’. The activation of early phenylpropanoid biosynthesis genes, including ASP3, PAL, 4CL, PER, CHS, CYP98A and F3’H, was responsible for anthocyanin accumulation in mutants. In addition, IAA and ABA had a positive regulatory effect on the synthesis of anthocyanins, while GA had the reverse effect. The down-regulation of AACT1, HMGS, HMGR, MVK, MVD2, IDI1 and FPPS2 involved in terpenoid biosynthesis influences anthocyanin accumulation by positively regulating transcripts of AUX1 and SAUR that contribute to the synthesis of IAA, GID2 to GA, PP2C and SnRK2 to ABA. Furthermore, MYB and bHLH members, which are highly correlated (r=0.882–0.980) with anthocyanin content, modulated anthocyanin accumulation by regulating the transcription of structural genes, including CHS and F3’H, involved in the flavonoid biosynthesis pathway.

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Induction of Anthocyanin Accumulation in Crabapple (Malus cv.) Leaves by Low Temperatures

HortScience ◽

10.21273/hortsci.50.5.640 ◽

2015 ◽

Vol 50 (5) ◽

pp. 640-649 ◽

Cited By ~ 4

Author(s):

Ji Tian ◽

Zhen-yun Han ◽

Li-ru Zhang ◽

Ting-Ting Song ◽

Jie Zhang ◽

...

Keyword(s):

Low Temperatures ◽

Anthocyanin Biosynthesis ◽

Anthocyanin Accumulation ◽

Human Diet ◽

Helix Loop Helix ◽

Leaf Coloration ◽

Regulatory Complex ◽

R2r3 Myb ◽

Reverse Transcript ◽

Anthocyanin Biosynthetic Genes

Anthocyanins are protective pigments that accumulate in plant organs such as fruits and leaves, and are nutritionally valuable components of the human diet. There is thus considerable interest in the factors that regulate synthesis. Malus crabapple leaves are rich sources of these compounds, and in this study we analyzed leaf coloration, anthocyanin levels, and the expression levels of anthocyanin biosynthetic and regulatory genes in three crabapple cultivars (Royalty, Prairifire, and Flame) following various temperature treatments. We found that low temperatures (LTs) promoted anthocyanin accumulation in ‘Royalty’ and ‘Prairifire’, leading to red leaves, but not in ‘Flame’, which accumulated abundant colorless flavonols and retained green colored leaves. Quantitative reverse transcript PCR (RT-PCR) analyses indicated that the expression of several anthocyanin biosynthetic genes was induced by LTs, as were members of the R2R3-MYB, basic helix–loop–helix (bHLH) and WD40 transcription factor families that are thought to act in a complex. We propose that anthocyanin biosynthesis is differentially regulated in the three cultivars by LTs via the expression of members of this anthocyanin regulatory complex.

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Transcriptome profiling of anthocyanin-related genes reveals effects of light intensity on anthocyanin biosynthesis in red leaf lettuce

PeerJ ◽

10.7717/peerj.4607 ◽

2018 ◽

Vol 6 ◽

pp. e4607 ◽

Cited By ~ 14

Author(s):

Yanzhao Zhang ◽

Shuzhen Xu ◽

Yanwei Cheng ◽

Zhengfeng Peng ◽

Jianming Han

Keyword(s):

Light Intensity ◽

Molecular Mechanisms ◽

De Novo ◽

Anthocyanin Biosynthesis ◽

Gene Annotation ◽

High Irradiance ◽

High Light ◽

Anthocyanin Content ◽

Structural Genes ◽

Leaf Lettuce

Red leaf lettuce (Lactuca sativaL.) is popular due to its high anthocyanin content, but poor leaf coloring often occurs under low light intensity. In order to reveal the mechanisms of anthocyanins affected by light intensity, we compared the transcriptome ofL. sativaL. var.capitataunder light intensities of 40 and 100 μmol m−2s−1. A total of 62,111 unigenes were de novo assembled with an N50 of 1,681 bp, and 48,435 unigenes were functionally annotated in public databases. A total of 3,899 differentially expressed genes (DEGs) were detected, of which 1,377 unigenes were up-regulated and 2,552 unigenes were down-regulated in the high light samples. By Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the DEGs were significantly enriched in 14 pathways. Using gene annotation and phylogenetic analysis, we identified seven anthocyanin structural genes, includingCHS,CHI,F3H,F3′H,DFR,ANS, and3GT, and two anthocyanin transport genes,GSTandMATE. In terms of anthocyanin regulatory genes, five MYBs and one bHLH gene were identified. AnHY5gene was discovered, which may respond to light-signaling and regulate anthocyanin structural genes. These genes showed a log2FC of 2.7–9.0 under high irradiance, and were validated using quantitative real-time-PCR. In conclusion, our results indicated transcriptome variance in red leaf lettuce under low and high light intensity, and observed a anthocyanin biosynthesis and regulation pattern. The data should further help to unravel the molecular mechanisms of anthocyanins influenced by light intensity.

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Comparative Transcriptome Analysis of the Accumulation of Anthocyanins Revealed the Underlying Metabolic and Molecular Mechanisms of Purple Pod Coloration in Okra (Abelmoschus esculentus L.)

Foods ◽

10.3390/foods10092180 ◽

2021 ◽

Vol 10 (9) ◽

pp. 2180

Author(s):

Yanjie Zhang ◽

Tianjiao Zhang ◽

Qing Zhao ◽

Xiaodong Xie ◽

Yan Li ◽

...

Keyword(s):

Molecular Mechanisms ◽

Abelmoschus Esculentus ◽

Anthocyanin Accumulation ◽

Comparative Transcriptome ◽

Structural Genes ◽

Anthocyanin Pigmentation ◽

Transcriptomic Data ◽

Working Models ◽

Daily Diet ◽

First Time

Color is an essential agronomic trait and the consumption of high anthocyanin containing vegetables in daily diet does provide benefits to human health, but the mechanisms on anthocyanin accumulation in tender pods of okra (Abelmoschus esculentus L.) were totally unknown. In this study, a wide characterization and quantitation of anthocyanins and flavonols in tender pods of 15 okra varieties were performed by UHPLC-Q-Orbitrap HRMS for the first time. Two major anthocyanins (delphinidin 3-O-sambubioside and cyanidin 3-O-sambubioside) and six kinds of flavonol glycosides (most are quercetin-based) were identified and quantified. The coloration of the purple okra pod mainly arises from the accumulation of both delphinidin 3-O-sambubioside and cyanidin 3-O-sambubioside in most of purple varieties (Hong Yu, Bowling Red and Burgundy), except Jing Orange. The significant differences in the compositions and contents of anthocyanins are responsible for the pod color ranging from brick-red to purplish-red among the various okra cultivars. Furthermore, four representative okra cultivars exhibiting obvious differences in anthocyanin accumulation were further analyzed with transcriptome and more than 4000 conserved differentially expressed genes were identified across the three compared groups (B vs. BR, B vs. HY and B vs. JO). Based on the comprehensive analysis of transcriptomic data, it was indicated that MBW complex consisting of AeMYB114, AeTT8, and AeTTG1 and other transcriptional factors coordinately regulate the accumulation of anthocyanins via the transcriptional regulation of structural genes. Moreover, four independent working models explaining the diversities of anthocyanin pigmentation in okra pods were also proposed. Altogether, these results improved our understanding on anthocyanin accumulation in okra pods, and provided strong supports for the development of okra pod as a functional food in the future.

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The combination of R2R3-MYB gene AmRosea1 and hairy root culture is a useful tool for rapidly induction and production of anthocyanins in Antirrhinum majus L

AMB Express ◽

10.1186/s13568-021-01286-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chunlan Piao ◽

Jinguo Wu ◽

Min-Long Cui

Keyword(s):

Hairy Roots ◽

Anthocyanin Biosynthesis ◽

Ectopic Expression ◽

Root Culture ◽

Hairy Root Culture ◽

Anthocyanin Accumulation ◽

Structural Genes ◽

Myb Gene ◽

Transformed Hairy Roots ◽

R2r3 Myb

AbstractAnthocyanins are the largest group of water-soluble pigments and beneficial for human health. Although most plants roots have the potential to express natural biosynthesis pathways required to produce specialized metabolites such as anthocyanins, the anthocyanin synthesis is specifically silenced in roots. To explore the molecular mechanism of absence and production ability of anthocyanin in the roots, investigated the effect of a bHLH gene AmDelila, and an R2R3-MYB gene AmRosea1, which are the master regulators of anthocyanin biosynthesis in Antirrhinum majus flowers, by expressing these genes in transformed hairy roots of A. majus. Co-ectopic expression of both AmDelila and AmRosea1 significantly upregulated the expression of the key target structural genes in the anthocyanin biosynthesis pathway. Furthermore, this resulted in strongly enhanced anthocyanin accumulation in transformed hairy roots. Ectopic expression of AmDelila alone did not gives rise to any significant anthocyanin accumulation, however, ectopic expression of AmRosea1 alone clearly upregulated expression of the main structural genes as well as greatly promoted anthocyanin accumulation in transformed hairy roots, where the contents reached 0.773–2.064 mg/g fresh weight. These results suggest that AmRosea1 plays a key role in the regulatory network in controlling the initiation of anthocyanin biosynthesis in roots, and the combination of AmRosea1 and hairy root culture is a powerful tool to study and production of anthocyanins in the roots of A. majus.

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Grapevine fanleaf virus affects grape (Vitis vinifera) berry anthocyanin content via the transcriptional regulation of anthocyanin biosynthetic genes

Functional Plant Biology ◽

10.1071/fp18014 ◽

2018 ◽

Vol 45 (7) ◽

pp. 771

Author(s):

Maja Rupnik-Cigoj ◽

Anastazija Jež-Krebelj ◽

Simone D. Castellarin ◽

Kajetan Trošt ◽

Paolo Sivilotti ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Anthocyanin Content ◽

Grapevine Fanleaf Virus ◽

Flavonoid Biosynthetic Pathway ◽

North Eastern ◽

Anthocyanin Concentration ◽

Healthy Control ◽

Berry Composition ◽

Derivatives Of ◽

Anthocyanin Biosynthetic Genes

Grapevine fanleaf virus (GFLV) causes grapevine fanleaf degeneration, one of the oldest known viral diseases of grapevines. The virus has been found in all winegrowing regions around the world. In the seasons 2011–12 a comparison between field grown GFLV-infected and healthy grapevines was conducted for the cultivars Schioppettino in North-Eastern Italy and Refošk in South-Western Slovenia. Our research showed that GFLV infection caused a drop of the yield due to reduction of both cluster weight and berry weight. Besides the yield, the berry composition was also affected; in detail, anthocyanin concentration increased in both varieties but significantly only in the case of Schioppettino. Upregulation of the F3ʹ5ʹH gene and downregulation of F3ʹH gene in the berries of GFLV infected vines compared with the ones of healthy control vines resulted in modified proportions between di- and tri- hydroxylated or methylated derivatives of anthocyanins. The F3H1 gene was identified to be the most strongly regulated gene of the flavonoid biosynthetic pathway by GFLV infection, indicating its important role in increasing anthocyanin concentration in grapes of GFLV infected vines as compared with healthy controls.

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Light- and Temperature-Induced Expression of an R2R3-MYB Gene Regulates Anthocyanin Biosynthesis in Red-Fleshed Kiwifruit

International Journal of Molecular Sciences ◽

10.3390/ijms20205228 ◽

2019 ◽

Vol 20 (20) ◽

pp. 5228 ◽

Cited By ~ 1

Author(s):

Min Yu ◽

Yuping Man ◽

Yanchang Wang

Keyword(s):

Transcriptional Activation ◽

Anthocyanin Biosynthesis ◽

Physiological Role ◽

Regulatory Function ◽

Anthocyanin Content ◽

Anthocyanin Accumulation ◽

Virus Induced Gene Silencing ◽

Highly Correlated ◽

Myb Genes ◽

R2r3 Myb

The R2R3 MYB genes associated with the flavonoid/anthocyanidin pathway feature two repeats, and represent the most abundant classes of MYB genes in plants; however, the physiological role and regulatory function of most R2R3 MYBs remain poorly understood in kiwifruit (Actinidia). Here, genome-wide analysis identified 155 R2R3-MYBs in the ‘Red 5′ version of the Actinidia chinensis genome. Out of 36 anthocyanin-related AccR2R3-MYBs, AcMYB10 was the most highly expressed in inner pericarp of red-fleshed kiwifruit. The expression of AcMYB10 was highly correlated with anthocyanin accumulation in natural pigmentation during fruit ripening and light-/temperature-induced pigmentation in the callus. AcMYB10 is localized in the nuclei and has transcriptional activation activity. Overexpression of AcMYB10 elevates anthocyanin accumulation in transgenic A. chinensis. In comparison, A. chinensis fruit infiltrated with virus-induced gene silencing showed delayed red coloration, lower anthocyanin content, and lower expression of AcMYB10. The transient expression experiment in Nicotiana tabacum leaves and Actinidia arguta fruit indicated the interaction of AcMYB10 with AcbHLH42 might strongly activate anthocyanin biosynthesis by activating the transcription of AcLDOX and AcF3GT. In conclusion, this study provides novel molecular information about R2R3-MYBs in kiwifruit, advances our understanding of light- and temperature-induced anthocyanin accumulation, and demonstrates the important function of AcMYB10 in the biosynthesis of anthocyanin in kiwifruit.

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The Light-Induced WD40-Repeat Transcription Factor DcTTG1 Regulates Anthocyanin Biosynthesis in Dendrobium candidum

Frontiers in Plant Science ◽

10.3389/fpls.2021.633333 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ning Jia ◽

Jingjing Wang ◽

Yajuan Wang ◽

Wei Ye ◽

Jiameng Liu ◽

...

Keyword(s):

Transcription Factor ◽

Molecular Mechanisms ◽

Anthocyanin Biosynthesis ◽

Raw Material ◽

Anthocyanin Synthesis ◽

Anthocyanin Content ◽

Anthocyanin Accumulation ◽

Wd40 Repeat ◽

Strong Light ◽

Dendrobium Candidum

Dendrobium candidum is used as a traditional Chinese medicine and as a raw material in functional foods. D. candidum stems are green or red, and red stems are richer in anthocyanins. Light is an important environmental factor that induces anthocyanin accumulation in D. candidum. However, the underlying molecular mechanisms have not been fully unraveled. In this study, we exposed D. candidum seedlings to two different light intensities and found that strong light increased the anthocyanin content and the expression of genes involved in anthocyanin biosynthesis. Through transcriptome profiling and expression analysis, we identified a WD40-repeat transcription factor, DcTTG1, whose expression is induced by light. Yeast one-hybrid assays showed that DcTTG1 binds to the promoters of DcCHS2, DcCHI, DcF3H, and DcF3′H, and a transient GUS activity assay indicated that DcTTG1 can induce their expression. In addition, DcTTG1 complemented the anthocyanin deficiency phenotype of the Arabidopsis thaliana ttg1-13 mutant. Collectively, our results suggest that light promotes anthocyanin accumulation in D. candidum seedlings via the upregulation of DcTTG1, which induces anthocyanin synthesis-related gene expression.

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