Cloning and Functional Analysis of R2R3 MYB Genes Involved in Anthocyanin Biosynthesis in Potato Tuber

Abstract Abstract Background: Anthocyanins contribute to coloration and antioxidation effects in different plant tissues. MYB transcription factors have been demonstrated to be a key regulator for anthocyanin synthesis in many plants. However, little information was available about the MYB genes in the halophyte species Eutrema salsugineum . Result: Here we report the identification of an important anthocyanin biosynthesis regulator Es MYB90 from Eutrema salsugineum , which is a halophyte tolerant to multiple abiotic stresses. Our phylogenetic and localization analyses supported that Es MYB90 is an R2R3 type of MYB transcription factor. Ectopic expression of EsMYB90 in tobacco and Arabidopsis enhanced pigmentation and anthocyanin accumulation in various organs. The transcriptome analysis revealed that 42 genes upregulated by Es MYB90 in 35S : EsMYB90 tobacco transgenic plants are required for anthocyanin biosynthesis. Moreover, our qRT-PCR results showed that Es MYB90 promoted expression of early ( PAL , CHS , and CHI ) and late ( DFR , ANS , and UFGT ) anthocyanin biosynthesis genes in stems, leaves, and flowers of 35S : EsMYB90 tobacco transgenic plants. Conclusions: Our results indicated that Es MYB90 is a MYB transcription factor, which regulates anthocyanin biosynthesis genes to control anthocyanin biosynthesis. Our work provides a new tool to enhance anthocyanin production in various plants. Keywords : Anthocyanin, flavonoid, Eutrema salsugineum , R2R3 MYB transcription factor, Es MYB90, transcriptional regulation, anthocyanin biosynthesis genes.

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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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Identification of the Eutrema Salsugineum EsMYB90 gene important for anthocyanin biosynthesis

10.21203/rs.2.18301/v3 ◽

2020 ◽

Author(s):

Yuting Qi ◽

Caihong Gu ◽

Xingjun Wang ◽

Shiqing Gao ◽

Changsheng Li ◽

...

Keyword(s):

Transcription Factor ◽

Transgenic Plants ◽

Anthocyanin Biosynthesis ◽

Ectopic Expression ◽

Myb Transcription Factor ◽

Anthocyanin Synthesis ◽

Eutrema Salsugineum ◽

Tobacco Transgenic Plants ◽

Myb Genes ◽

R2r3 Myb

Abstract Background: Anthocyanins contribute to coloration and antioxidation effects in different plant tissues. MYB transcription factors have been demonstrated to be a key regulator for anthocyanin synthesis in many plants. However, little information was available about the MYB genes in the halophyte species Eutrema salsugineum . Result: Here we report the identification of an important anthocyanin biosynthesis regulator Es MYB90 from Eutrema salsugineum , which is a halophyte tolerant to multiple abiotic stresses. Our phylogenetic and localization analyses supported that Es MYB90 is an R2R3 type of MYB transcription factor. Ectopic expression of EsMYB90 in tobacco and Arabidopsis enhanced pigmentation and anthocyanin accumulation in various organs. The transcriptome analysis revealed that 42 genes upregulated by Es MYB90 in 35S : EsMYB90 tobacco transgenic plants are required for anthocyanin biosynthesis. Moreover, our qRT-PCR results showed that Es MYB90 promoted expression of early ( PAL , CHS , and CHI ) and late ( DFR , ANS , and UFGT ) anthocyanin biosynthesis genes in stems, leaves, and flowers of 35S : EsMYB90 tobacco transgenic plants. Conclusions: Our results indicated that Es MYB90 is a MYB transcription factor, which regulates anthocyanin biosynthesis genes to control anthocyanin biosynthesis. Our work provides a new tool to enhance anthocyanin production in various plants. Keywords : Anthocyanin, flavonoid, Eutrema salsugineum , R2R3 MYB transcription factor, Es MYB90, transcriptional regulation, anthocyanin biosynthesis genes.

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StMYB44 negatively regulates anthocyanin biosynthesis at high temperatures in tuber flesh of potato

Journal of Experimental Botany ◽

10.1093/jxb/erz194 ◽

2019 ◽

Vol 70 (15) ◽

pp. 3809-3824 ◽

Cited By ~ 13

Author(s):

Yuhui Liu ◽

Kui Lin-Wang ◽

Richard V Espley ◽

Li Wang ◽

Yuanming Li ◽

...

Keyword(s):

Heat Stress ◽

High Temperature ◽

Potato Tuber ◽

High Temperatures ◽

Anthocyanin Biosynthesis ◽

Solanum Tuberosum L ◽

Lignin Biosynthesis ◽

Phenylpropanoid Pathway ◽

Anthocyanin Accumulation ◽

R2r3 Myb

Abstract High temperatures are known to reduce anthocyanin accumulation in a number of diverse plant species. In potato (Solanum tuberosum L.), high temperature significantly reduces tuber anthocyanin pigment content. However, the mechanism of anthocyanin biosynthesis in potato tuber under heat stress remains unknown. Here we show that high temperature causes reduction of anthocyanin biosynthesis in both potato tuber skin and flesh, with white areas forming between the vasculature and periderm. Heat stress reduced the expression of the R2R3 MYB transcription factors (TFs) StAN1 and StbHLH1, members of the transcriptional complex responsible for coordinated regulation of the skin and flesh pigmentation, as well as anthocyanin biosynthetic pathway genes in white regions. However, the core phenylpropanoid pathway, lignin, and chlorogenic acid (CGA) pathway genes were up-regulated in white areas, suggesting that suppression of the anthocyanin branch may result in re-routing phenylpropanoid flux into the CGA or lignin biosynthesis branches. Two R2R3 MYB TFs, StMYB44-1 and StMYB44-2, were highly expressed in white regions under high temperature. In transient assays, StMYB44 represses anthocyanin accumulation in leaves of Nicotiana tabacum and N. benthamiana by directly suppressing the activity of the dihydroflavonol reductase (DFR) promoter. StMYB44-1 showed stronger repressive capacity than StMYB44-2, with both predicted proteins containing the repression-associated EAR motif with some variation. StMYB44-1 conferred repression without a requirement for a basic helix–loop–helix (bHLH) partner, suggesting a different repression mechanism from that of reported anthocyanin repressors. We propose that temperature-induced reduction of anthocyanin accumulation in potato flesh is caused by down-regulation of the activating anthocyanin regulatory complex, by enhancing the expression of flesh-specific StMYB44 and alteration of phenylpropanoid flux.

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Transcriptomic Analysis of Ficus carica Peels with a Focus on the Key Genes for Anthocyanin Biosynthesis

International Journal of Molecular Sciences ◽

10.3390/ijms21041245 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1245

Author(s):

Jing Li ◽

Yuyan An ◽

Liangju Wang

Keyword(s):

Molecular Mechanisms ◽

Anthocyanin Biosynthesis ◽

Ficus Carica ◽

Molecular Characteristics ◽

Horticultural Traits ◽

Deciduous Fruit ◽

Deciduous Fruit Tree ◽

Sequences Analysis ◽

Myb Genes ◽

R2r3 Myb

Fig (Ficus carica L.), a deciduous fruit tree of the Moraceae, provides ingredients for human health such as anthocyanins. However, little information is available on its molecular structure. In this study, the fig peels in the yellow (Y) and red (R) stages were used for transcriptomic analyses. Comparing the R with the Y stage, we obtained 6224 differentially expressed genes, specifically, anthocyanin-related genes including five CHS, three CHI, three DFR, three ANS, two UFGT and seven R2R3-MYB genes. Furthermore, three anthocyanin biosynthetic genes, i.e., FcCHS1, FcCHI1 and FcDFR1, and two R2R3-MYB genes, i.e., FcMYB21 and FcMYB123, were cloned; sequences analysis and their molecular characteristics indicated their important roles in fig anthocyanin biosynthesis. Heterologous expression of FcMYB21 and FcMYB123 significantly promoted anthocyanin accumulation in both apple fruits and calli, further suggesting their regulatory roles in fig coloration. These findings provide novel insights into the molecular mechanisms behind fig anthocyanin biosynthesis and coloration, facilitating the genetic improvement of high-anthocyanin cultivars and other horticultural traits in fig fruits.

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Identification and functional analysis of three new anthocyanin R2R3-MYB genes inPetunia

Plant Direct ◽

10.1002/pld3.114 ◽

2019 ◽

Vol 3 (1) ◽

pp. e00114 ◽

Cited By ~ 7

Author(s):

Hechen Zhang ◽

Ronald Koes ◽

Hongquan Shang ◽

Zhenzhu Fu ◽

Limin Wang ◽

...

Keyword(s):

Functional Analysis ◽

Myb Genes ◽

R2r3 Myb

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OsMYB3 is a R2R3-MYB gene responsible for anthocyanin biosynthesis in black rice

Molecular Breeding ◽

10.1007/s11032-021-01244-x ◽

2021 ◽

Vol 41 (8) ◽

Author(s):

Jie Zheng ◽

Hao Wu ◽

Mingchao Zhao ◽

Zenan Yang ◽

Zaihui Zhou ◽

...

Keyword(s):

Anthocyanin Biosynthesis ◽

Black Rice ◽

Myb Gene ◽

R2r3 Myb

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The MIR-Domain of PbbHLH2 Is Involved in Regulation of the Anthocyanin Biosynthetic Pathway in ”Red Zaosu” (PyrusBretschneideri Rehd.) Pear Fruit

International Journal of Molecular Sciences ◽

10.3390/ijms22063026 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3026

Author(s):

Xieyu Li ◽

Fangxin Xiang ◽

Wei Han ◽

Bingqing Qie ◽

Rui Zhai ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Anthocyanin Biosynthesis ◽

Bimolecular Fluorescence Complementation ◽

Anthocyanin Content ◽

Pear Fruit ◽

Fruit Peel ◽

Interaction Domain ◽

Dihydroflavonol Reductase ◽

Anthocyanin Biosynthetic Pathway ◽

R2r3 Myb

The N-terminal of Myc-like basic helix-loop-helix transcription factors (bHLH TFs) contains an interaction domain, namely the MYB-interacting region (MIR), which interacts with the R2R3-MYB proteins to regulate genes involved in the anthocyanin biosynthetic pathway. However, the functions of MIR-domain bHLHs in this pathway are not fully understood. In this study, PbbHLH2 containing the MIR-domain was identified and its function investigated. The overexpression of PbbHLH2 in ”Zaosu” pear peel increased the anthocyanin content and the expression levels of late biosynthetic genes. Bimolecular fluorescence complementation showed that PbbHLH2 interacted with R2R3-MYB TFs PbMYB9, 10, and 10b in onion epidermal cells and confirmed that MIR-domain plays important roles in the interaction between the MIR-domain bHLH and R2R3-MYB TFs. Moreover, PbbHLH2 bound and activated the dihydroflavonol reductase promoter in yeast one-hybrid (Y1H) and dual-luciferase assays. Taken together these results suggested that the MIR domain of PbbHLH2 regulated anthocyanin biosynthesis in pear fruit peel.

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An R2R3-MYB transcription factor CmMYB21 represses anthocyanin biosynthesis in color fading petals of chrysanthemum

Scientia Horticulturae ◽

10.1016/j.scienta.2021.110674 ◽

2022 ◽

Vol 293 ◽

pp. 110674

Author(s):

Yiguang Wang ◽

Li-Jie Zhou ◽

Yuxi Wang ◽

Zhiqiang Geng ◽

Baoqing Ding ◽

...

Keyword(s):

Transcription Factor ◽

Anthocyanin Biosynthesis ◽

Myb Transcription Factor ◽

Color Fading ◽

R2r3 Myb

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Genome-wide identification, functional prediction, and evolutionary analysis of the R2R3-MYB superfamily in Brassica napus

Genome ◽

10.1139/gen-2017-0059 ◽

2017 ◽

Vol 60 (10) ◽

pp. 797-814 ◽

Cited By ~ 23

Author(s):

Ali Hajiebrahimi ◽

Hajar Owji ◽

Shiva Hemmati

Keyword(s):

Brassica Napus ◽

Purifying Selection ◽

Gene Clusters ◽

Regulatory Elements ◽

Post Inoculation ◽

Evolutionary Analysis ◽

Salinity Treatment ◽

Myb Genes ◽

R2r3 Myb ◽

Leptosphaeria Biglobosa

R2R3-MYB transcription factors (TFs) have been shown to play important roles in plants, including in development and in various stress conditions. Phylogenetic analysis showed the presence of 249 R2R3-MYB TFs in Brassica napus, called BnaR2R3-MYB TFs, clustered into 38 clades. BnaR2R3-MYB TFs were distributed on 19 chromosomes of B. napus. Sixteen gene clusters were identified. BnaR2R3-MYB TFs were characterized by motif prediction, gene structure analysis, and gene ontology. Evolutionary analysis revealed that BnaR2R3-MYB TFs are mainly formed as a result of whole-genome duplication. Orthologs and paralogs of BnaR2R3-MYB TFs were identified in B. napus, B. rapa, B. oleracea, and Arabidopsis thaliana using synteny-based methods. Purifying selection was pervasive within R2R3-MYB TFs. Kn/Ks values lower than 0.3 indicated that BnaR2R3-MYB TFs are being functionally converged. The role of gene conversion in the formation of BnaR2R3-MYB TFs was significant. Cis-regulatory elements in the upstream regions of BnaR2R3-MYB genes, miRNA targeting BnaR2R3MYB TFs, and post translational modifications were identified. Digital expression data revealed that BnaR2R3-MYB genes were highly expressed in the roots and under high salinity treatment after 24 h. BnaMYB21, BnaMYB141, and BnaMYB148 have been suggested for improving salt-tolerant B. napus. BnaR2R3-MYB genes were mostly up regulated on the 14th day post inoculation with Leptosphaeria biglobosa and L. maculan. BnaMYB150 is a candidate for increased tolerance to Leptospheria in B. napus.

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