Repression of anthocyanin biosynthesis by R3-MYB transcription factors in lily (Lilium spp.)

2019 ◽  
Vol 38 (5) ◽  
pp. 609-622 ◽  
Author(s):  
Moeko Sakai ◽  
Masumi Yamagishi ◽  
Kohei Matsuyama
Keyword(s):  
Transcription Factors ◽  
Anthocyanin Biosynthesis ◽  
Myb Transcription Factors

scholarly journals Regulation of MYB Transcription Factors of Anthocyanin Synthesis in Lily Flowers

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaojuan Yin ◽  
Yibing Zhang ◽  
Li Zhang ◽  
Baohua Wang ◽  
Yidi Zhao ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Transient Expression ◽  
Anthocyanin Biosynthesis ◽  
Gene Promoter ◽  
Flower Color ◽  
Preliminary Evidence ◽  
Anthocyanin Synthesis ◽  
Myb Transcription Factors ◽  
Color Formation ◽  
R2r3 Myb

Flower color is the decisive factor that affects the commercial value of ornamental flowers. Therefore, it is important to study the regulation of flower color formation in lily to discover the positive and negative factors that regulate this important trait. In this study, MYB transcription factors (TFs) were characterized to understand the regulatory mechanism of anthocyanin biosynthesis in lily. Two R2R3-MYB TFs, LvMYB5, and LvMYB1, were found to regulate anthocyanin biosynthesis in lily flowers. LvMYB5, which has an activation motif, belongs to the SG6 MYB protein subgroup of Arabidopsis thaliana. Transient expression of LvMYB5 indicated that LvMYB5 can promote coloration in Nicotiana benthamiana leaves, and that expression of LvMYB5 increases the expression levels of NbCHS, NbDFR, and NbANS. VIGS experiments in lily petals showed that the accumulation of anthocyanins was reduced when LvMYB5 was silenced. Luciferase assays showed that LvMYB5 can promote anthocyanin synthesis by activating the ANS gene promoter. Therefore, LvMYB5 plays an important role in flower coloration in lily. In addition, the transient expression experiment provided preliminary evidence that LvMYB1 (an R2R3-MYB TF) inhibits anthocyanin synthesis in lily flowers. The discovery of activating and inhibitory factors related to anthocyanin biosynthesis in lily provides a theoretical basis for improving flower color through genetic engineering. The results of our study provide a new direction for the further study of the mechanisms of flower color formation in lilies.

scholarly journals Identification of Two Novel R2R3-MYB Transcription factors, PsMYB114L and PsMYB12L, Related to Anthocyanin Biosynthesis in Paeonia suffruticosa

2019 ◽  
Vol 20 (5) ◽  
pp. 1055 ◽  
Author(s):  
Xinpeng Zhang ◽  
Zongda Xu ◽  
Xiaoyan Yu ◽  
Lanyong Zhao ◽  
Mingyuan Zhao ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Anthocyanin Biosynthesis ◽  
Critical Role ◽  
Flower Color ◽  
Anthocyanin Accumulation ◽  
Paeonia Suffruticosa ◽  
Myb Transcription Factors ◽  
Transgenic Lines ◽  
R2r3 Myb ◽  
R2r3 Myb Transcription Factors

Flower color is a charming phenotype with very important ornamental and commercial values. Anthocyanins play a critical role in determining flower color pattern formation, and their biosynthesis is typically regulated by R2R3-MYB transcription factors (TFs). Paeonia suffruticosa is a famous ornamental plant with colorful flowers. However, little is known about the R2R3-MYB TFs that regulate anthocyanin accumulation in P. suffruticosa. In the present study, two R2R3-MYB TFs, namely, PsMYB114L and PsMYB12L, were isolated from the petals of P. suffruticosa ‘Shima Nishiki’ and functionally characterized. Sequence analysis suggested that PsMYB114L contained a bHLH-interaction motif, whereas PsMYB12L contained two flavonol-specific motifs (SG7 and SG7-2). Subsequently, the in vivo function of PsMYB114L and PsMYB12L was investigated by their heterologous expression in Arabidopsis thaliana and apple calli. In transgenic Arabidopsis plants, overexpression of PsMYB114L and of PsMYB12L caused a significantly higher accumulation of anthocyanins, resulting in purple-red leaves. Transgenic apple calli overexpressing PsMYB114L and PsMYB12L also significantly enhanced the anthocyanins content and resulted in a change in the callus color to red. Meanwhile, gene expression analysis in A. thaliana and apple calli suggested that the expression levels of the flavonol synthase (MdFLS) and anthocyanidin reductase (MdANR) genes were significantly downregulated and the dihydroflavonol 4-reductase (AtDFR) and anthocyanin synthase (AtANS) genes were significantly upregulated in transgenic lines of PsMYB114L. Moreover, the expression level of the FLS gene (MdFLS) was significantly downregulated and the DFR (AtDFR/MdDFR) and ANS (AtANS/MdANS) genes were all significantly upregulated in transgenic lines plants of PsMYB12L. These results indicate that PsMYB114L and PsMYB12L both enhance anthocyanin accumulation by specifically regulating the expression of some anthocyanin biosynthesis-related genes in different plant species. Together, these results provide a valuable resource with which to further study the regulatory mechanism of anthocyanin biosynthesis in P. suffruticosa and for the breeding of tree peony cultivars with novel and charming flower colors.

Advance of the negative regulation of anthocyanin biosynthesis by MYB transcription factors

2019 ◽  
Vol 136 ◽  
pp. 178-187 ◽  
Author(s):  
Linhuan Chen ◽  
Bing Hu ◽  
Yonghua Qin ◽  
Guibing Hu ◽  
Jietang Zhao
Keyword(s):  
Transcription Factors ◽  
Anthocyanin Biosynthesis ◽  
Negative Regulation ◽  
Myb Transcription Factors

MdMYBL2 helps regulate cytokinin-induced anthocyanin biosynthesis in red-fleshed apple (Malus sieversii f. niedzwetzkyana) callus

2019 ◽  
Vol 46 (2) ◽  
pp. 187 ◽  
Author(s):  
Yicheng Wang ◽  
Jingjing Sun ◽  
Nan Wang ◽  
Haifeng Xu ◽  
Changzhi Qu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Molecular Mechanisms ◽  
Anthocyanin Biosynthesis ◽  
Bimolecular Fluorescence Complementation ◽  
Structural Genes ◽  
Myb Transcription Factors ◽  
Malus Sieversii ◽  
Transcription Factor Genes ◽  
Transgenic Callus

Anthocyanin biosynthesis is induced by cytokinins, and is regulated by MYB transcription factors. However, the underlying molecular mechanisms have not been fully characterised. In the present study, red-fleshed apple callus were induced from the leaves of an R6/R6 homozygous line, which was the hybrid offspring of Malus sieversii f. niedzwetzkyana and ‘Fuji’. We analysed the callus anthocyanin contents in response to different cytokinin concentrations. We observed that cytokinin treatments upregulated the expression of anthocyanin structural genes MdDFR and MdUFGT and transcription factor genes MdMYB10 and MdbHLH3. Additionally, the expression of MdMYBL2, which encodes the bHLH and EAR motifs, was inhibited by cytokinin treatments. The MdMYBL2-overexpressing callus had lower anthocyanin contents than the wild-type controls. We noted that the expression levels of anthocyanin biosynthesis structural genes MdDFR and MdUFGT and transcription factor genes MdMYB10 and MdbHLH3 were strongly suppressed in the transgenic callus. Subsequent yeast two-hybrid, bimolecular fluorescence complementation, and pull-down assays indicated that MdMYBL2 interacts with MdbHLH3, which may influence the expression of anthocyanin biosynthesis-related genes. Our findings may provide new insights into how MYB transcription factors influence the cytokinin-regulated anthocyanin biosynthesis in red-fleshed apples.

scholarly journals Genome-Wide Identification of the MYB Gene Family in Cymbidiumensifolium and Its Expression Analysis in Different Flower Colors

2021 ◽  
Vol 22 (24) ◽  
pp. 13245
Author(s):  
Yu-Jie Ke ◽  
Qing-Dong Zheng ◽  
Ya-He Yao ◽  
Yue Ou ◽  
Jia-Yi Chen ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Anthocyanin Biosynthesis ◽  
Flower Color ◽  
Floral Organ ◽  
Color Variation ◽  
Herbaceous Plant ◽  
Promoter Regions ◽  
Myb Transcription Factors ◽  
Cis Acting ◽  
Perennial Herbaceous Plant

MYB transcription factors of plants play important roles in flavonoid synthesis, aroma regulation, floral organ morphogenesis, and responses to biotic and abiotic stresses. Cymbidium ensifolium is a perennial herbaceous plant belonging to Orchidaceae, with special flower colors and high ornamental value. In this study, a total of 136 CeMYB transcription factors were identified from the genome of C. ensifolium, including 27 1R-MYBs, 102 R2R3-MYBs, 2 3R-MYBs, 2 4R-MYBs, and 3 atypical MYBs. Through phylogenetic analysis in combination with MYB in Arabidopsis thaliana, 20 clusters were obtained, indicating that these CeMYBs may have a variety of biological functions. The 136 CeMYBs were distributed on 18 chromosomes, and the conserved domain analysis showed that they harbored typical amino acid sequence repeats. The motif prediction revealed that multiple conserved elements were mostly located in the N-terminal of CeMYBs, suggesting their functions to be relatively conserved. CeMYBs harbored introns ranging from 0 to 13 and contained a large number of stress- and hormone-responsive cis-acting elements in the promoter regions. The subcellular localization prediction demonstrated that most of CeMYBs were positioned in the nucleus. The analysis of the CeMYBs expression based on transcriptome data showed that CeMYB52, and CeMYB104 of the S6 subfamily may be the key genes leading to flower color variation. The results lay a foundation for the study of MYB transcription factors of C. ensifolium and provide valuable information for further investigations of the potential function of MYB genes in the process of anthocyanin biosynthesis.

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