scholarly journals A novel transcription factor CmMYB012 inhibits flavone and anthocyanin biosynthesis in response to high temperatures in chrysanthemum

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Li-Jie Zhou ◽  
Zhiqiang Geng ◽  
Yuxi Wang ◽  
Yiguang Wang ◽  
Shenhui Liu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
High Temperatures ◽  
Anthocyanin Biosynthesis ◽  
Flower Color ◽  
Negative Influence ◽  
Myb Transcription Factor ◽  
Plant Fitness ◽  
Flavonoid Pathway ◽  
Gene Encoding ◽  
Color Formation

AbstractFlavones are among the major colorless pigments synthesized through branches of the flavonoid pathway in plants. However, due to the absence of a gene encoding flavone synthase (FNS) in the model plant Arabidopsis thaliana species, the regulatory mechanism of FNS-catalyzed flavone biosynthesis has rarely been studied in plants. Here, it was found that flavones play a predominant role in the elimination of excess reactive oxygen species (ROS) at high temperatures in colorless plant organs. A novel atypical subgroup 7 (SG7) R2R3-MYB transcription factor, CmMYB012, was found to be induced in response to prolonged high temperatures and to inhibit flavone biosynthesis by directly regulating CmFNS. Moreover, CmMYB012 was also found to inhibit anthocyanin biosynthesis by suppressing the expression of CmCHS, CmDFR, CmANS, and CmUFGT. CmMYB012 overexpression exerted a negative influence on plant fitness and pink flower color formation, while CmMYB012 suppression had the opposite effect in response to high temperatures. Our findings provide new insights into the mechanisms by which high temperatures regulate the metabolism of flavones and anthocyanins to affect plant fitness and flower color formation.

scholarly journals A R2R3-MYB Transcription Factor, VvMYBC2L2, Functions as a Transcriptional Repressor of Anthocyanin Biosynthesis in Grapevine (Vitis vinifera L.)

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 92 ◽  
Author(s):  
Ziguo Zhu ◽  
Guirong Li ◽  
Li Liu ◽  
Qingtian Zhang ◽  
Zhen Han ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Vitis Vinifera ◽  
Anthocyanin Biosynthesis ◽  
Transcriptional Repressor ◽  
Negative Regulator ◽  
Myb Transcription Factor ◽  
Vitis Vinifera L ◽  
Flavonoid Pathway ◽  
Leucoanthocyanidin Reductase ◽  
R2r3 Myb

In grapevine, the MYB transcription factors play an important role in the flavonoid pathway. Here, a R2R3-MYB transcription factor, VvMYBC2L2, isolated from Vitis vinifera cultivar Yatomi Rose, may be involved in anthocyanin biosynthesis as a transcriptional repressor. VvMYBC2L2 was shown to be a nuclear protein. The gene was shown to be strongly expressed in root, flower and seed tissue, but weakly expressed during the fruit development in grapevine. Overexpressing the VvMYBC2L2 gene in tobacco resulted in a very marked decrease in petal anthocyanin concentration. Expression analysis of flavonoid biosynthesis structural genes revealed that chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin reductase (LAR) and UDP glucose flavonoid 3-O-glucosyl transferase (UFGT) were strongly down-regulated in the VvMYBC2L2-overexpressed tobacco. In addition, transcription of the regulatory genes AN1a and AN1b was completely suppressed in transgenic plants. These results suggested that VvMYBC2L2 plays a role as a negative regulator of anthocyanin biosynthesis.

scholarly journals A P3A-Type ATPase and an R2R3-MYB Transcription Factor Are Involved in Vacuolar Acidification and Flower Coloration in Soybean

2020 ◽  
Vol 11 ◽  
Author(s):  
Jagadeesh Sundaramoorthy ◽  
Gyu Tae Park ◽  
Jeong-Dong Lee ◽  
Jeong Hoe Kim ◽  
Hak Soo Seo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Anthocyanin Biosynthesis ◽  
Stop Codon ◽  
Binding Capacity ◽  
Premature Stop Codon ◽  
Flower Color ◽  
Myb Transcription Factor ◽  
Nucleotide Substitutions ◽  
Vacuolar Acidification ◽  
Vacuolar Ph

The determination of flower color mainly depends on the anthocyanin biosynthesis pathway and vacuolar pH; however, unlike the former, the mechanism of vacuolar acidification in soybean remains uncharacterized at the molecular level. To investigate this mechanism, we isolated four recessive purple–blue EMS-induced flower mutants from the purple flower soybean cultivar, Pungsannamul. The petals of all the mutants had increased pH compared with those of wild Pungsannamul. One of the mutants had a single nucleotide substitution in GmPH4, a regulator gene encoding an MYB transcription factor, and the substitution resulted in a premature stop codon in its first exon. The other three mutants had nucleotide substitutions in GmPH5, a single new gene that we identified by physical mapping. It corresponds to Glyma.03G262600 in chromosome 3 and encodes a proton pump that belongs to the P3A-ATPase family. The substitutions resulted in a premature stop codon, which may be a defect in the ATP-binding capacity of GmPH5 and possibly a catalytic inefficiency of GmPH5. The result is consistent with their genetic recessiveness as well as the high pH of mutant petals, suggesting that GmPH5 is directly involved in vacuolar acidification. We also found that the expression of GmPH5 and several putative “acidifying” genes in the gmph4 mutant was remarkably reduced, indicating that GmPH4 may regulate the genes involved in determining the vacuolar pH of soybean petals.

scholarly journals Conserved and non-conserved functions of the rice homologs of the Arabidopsis trichome initiation-regulating MBW complex proteins

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaijie Zheng ◽  
Xutong Wang ◽  
Yating Wang ◽  
Shucai Wang
Keyword(s):  
Transcription Factor ◽  
Anthocyanin Biosynthesis ◽  
Transcriptional Activator ◽  
Myb Transcription Factor ◽  
Bhlh Transcription Factor ◽  
Seed Color ◽  
Transcription Activator ◽  
Root Hair Formation ◽  
Protoplast Transfection ◽  
Mbw Complex

Abstract Background Trichome initiation in Arabidopsis is regulated by a MYB-bHLH-WD40 (MBW) transcriptional activator complex formed by the R2R3 MYB transcription factor GLABRA1 (GL1), MYB23 or MYB82, the bHLH transcription factor GLABRA3 (GL3), ENHANCER OF GLABRA3 (EGL3) or TRANSPARENT TESTA8 (TT8), and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). However, the functions of the rice homologs of the MBW complex proteins remained uncharacterized. Results Based on amino acid sequence identity and similarity, and protein interaction prediction, we identified OsGL1s, OsGL3s and OsTTG1s as rice homologs of the MBW complex proteins. By using protoplast transfection, we show that OsGL1D, OsGL1E, OsGL3B and OsTTG1A were predominantly localized in the nucleus, OsGL3B functions as a transcriptional activator and is able to interact with GL1 and TTG1. By using yeast two-hybrid and protoplast transfection assays, we show that OsGL3B is able to interact with OsGL1E and OsTTG1A, and OsGL1E and OsTTG1A are also able to interact with GL3. On the other hand, we found that OsGL1D functions as a transcription activator, and it can interact with GL3 but not OsGL3B. Furthermore, our results show that expression of OsTTG1A in the ttg1 mutant restored the phenotypes including alternations in trichome and root hair formation, seed color, mucilage production and anthocyanin biosynthesis, indicating that OsTTG1A and TTG1 may have similar functions. Conclusion These results suggest that the rice homologs of the Arabidopsis MBW complex proteins are able to form MBW complexes, but may have conserved and non-conserved functions.

scholarly journals Transcriptomic Analysis of the Anthocyanin Biosynthetic Pathway Reveals the Molecular Mechanism Associated with Purple Color Formation in Dendrobium Nestor

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Xueqiang Cui ◽  
Jieling Deng ◽  
Changyan Huang ◽  
Xuan Tang ◽  
Xianmin Li ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Developmental Stages ◽  
Anthocyanin Biosynthesis ◽  
Transcriptome Profiling ◽  
Flower Color ◽  
Flower Bud ◽  
Color Formation ◽  
Color Development ◽  
Purple Coloration ◽  
Purple Color

Dendrobium nestor is a famous orchid species in the Orchidaceae family. There is a diversity of flower colorations in the Dendrobium species, but knowledge of the genes involved and molecular mechanism underlying the flower color formation in D. nestor is less studied. Therefore, we performed transcriptome profiling using Illumina sequencing to facilitate thorough studies of the purple color formation in petal samples collected at three developmental stages, namely—flower bud stage (F), half bloom stage (H), and full bloom stage (B) in D. nestor. In addition, we identified key genes and their biosynthetic pathways as well as the transcription factors (TFs) associated with purple flower color formation. We found that the phenylpropanoid–flavonoid–anthocyanin biosynthesis genes such as phenylalanine ammonia lyase, chalcone synthase, anthocyanidin synthase, and UDP-flavonoid glucosyl transferase, were largely up-regulated in the H and B samples as compared to the F samples. This upregulation might partly account for the accumulation of anthocyanins, which confer the purple coloration in these samples. We further identified several differentially expressed genes related to phytohormones such as auxin, ethylene, cytokinins, salicylic acid, brassinosteroid, and abscisic acid, as well as TFs such as MYB and bHLH, which might play important roles in color formation in D. nestor flower. Sturdy upregulation of anthocyanin biosynthetic structural genes might be a potential regulatory mechanism in purple color formation in D. nestor flowers. Several TFs were predicted to regulate the anthocyanin genes through a K-mean clustering analysis. Our study provides valuable resource for future studies to expand our understanding of flower color development mechanisms in D. nestor.

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

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

scholarly journals Characterization and Analysis of Anthocyanin-Related Genes in Wild-Type Blueberry and the Pink-Fruited Mutant Cultivar ‘Pink Lemonade’: New Insights into Anthocyanin Biosynthesis

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1296
Author(s):  
Jose V. Die ◽  
Richard W. Jones ◽  
Elizabeth L. Ogden ◽  
Mark K. Ehlenfeldt ◽  
Lisa J. Rowland
Keyword(s):  
Fruits And Vegetables ◽  
Anthocyanin Biosynthesis ◽  
Mechanistic Explanation ◽  
Comparative Sequence Analysis ◽  
Wild Type ◽  
Flavonoid Pathway ◽  
Transient Expression Assay ◽  
Gene Encoding ◽  
In The Wild ◽  
Anthocyanin Production

Blueberries are one of the richest sources of antioxidants, such as anthocyanins, among fruits and vegetables. Anthocyanin mutants, like the pink-fruited cultivar ‘Pink Lemonade’, are valuable resources for investigating anthocyanin biosynthesis in blueberries. In this study, we examined expression of flavonoid pathway genes during fruit development in wild-type, blue-fruited blueberries using quantitative real-time PCR. Expression was also compared between wild-type and the pink-fruited ‘Pink Lemonade’. This revealed significantly lower expression in ‘Pink Lemonade’ than in wild-type of nearly all the structural genes examined suggesting that a transcriptional regulator of the pathway was affected. Hence, we compared expression of three known regulatory genes and found that the gene encoding the transcription factor MYB1 was expressed at a significantly lower level in ‘Pink Lemonade’ than in the wild-type. To validate the capacity of this MYB1 to regulate the transcription of anthocyanin genes in blueberries, a transient expression assay was conducted. Results indicated MYB1 overexpression enhanced anthocyanin production. Comparative sequence analysis between wild-type and mutant MYB1 variants found differences in highly conserved features suggesting a mechanistic explanation for the mutant phenotype. Collectively, the results presented here contribute to a better understanding of mechanisms regulating anthocyanin biosynthesis in Vaccinium.

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