TCP3 interacts with R2R3-MYB proteins, promotes flavonoid biosynthesis and negatively regulates the auxin response inArabidopsis thaliana

Flavonoids belong to the family of polyphenolic secondary metabolites and contribute to fruit quality traits. It has been shown that MBW complexes (MYB-bHLH-WD40) regulate the flavonoids biosynthesis in different plants, but only a limited number of MBW complexes have been identified in strawberry species in general. In this study, we identified 112 R2R3-MYB proteins in woodland strawberry; 12 of them were found to have potential functions in regulating flavonoids biosynthesis by phylogenetic analysis. qRT-PCR assays showed that FvMYB3, FvMYB9, FvMYB11, FvMYB22, FvMYB64, and FvMYB105 mostly expressed at green stage of fruit development, aligned with proanthocyanidins accumulation; FvMYB10 and FvMYB41 showed higher expression levels at turning and ripe stages, aligned with anthocyanins accumulation. These results suggest that different MYBs might be involved in flavonoids biosynthesis at specific stages. Furthermore, FvMYB proteins were demonstrated to interact with FvbHLH proteins and induce expression from the promoters of CHS2 and DFR2 genes, which encode key enzymes in flavonoids biosynthesis. The co-expression of FvMYB and FvbHLH proteins in strawberry fruits also promoted the accumulation of proanthocyanidins. These findings confirmed and provided insights into the biofunction of MBW components in the regulation of flavonoid biosynthesis in woodland strawberry.

Download Full-text

NtbHLH1, a JAF13-like bHLH, interacts with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus

BMC Plant Biology ◽

10.1186/s12870-021-03050-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuxin Fan ◽

Jiayu Peng ◽

Jiacheng Wu ◽

Ping Zhou ◽

Ruijie He ◽

...

Keyword(s):

Flavonoid Biosynthesis ◽

Transcriptional Level ◽

Flavonoid Pathway ◽

Regulation Of Expression ◽

Over Expression ◽

Expression Of Genes ◽

Genes Encoding ◽

Regulatory Complex ◽

Positive Regulators ◽

R2r3 Myb

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

Download Full-text

The R2R3-MYB, bHLH, WD40, and related transcription factors in flavonoid biosynthesis

Functional & Integrative Genomics ◽

10.1007/s10142-012-0301-4 ◽

2012 ◽

Vol 13 (1) ◽

pp. 75-98 ◽

Cited By ~ 106

Author(s):

Lei Zhao ◽

Liping Gao ◽

Hongxue Wang ◽

Xiaotian Chen ◽

Yunsheng Wang ◽

...

Keyword(s):

Transcription Factors ◽

Flavonoid Biosynthesis ◽

R2r3 Myb

Download Full-text

Genome-Wide Analysis of the MYB Transcription Factor Superfamily in Physcomitrella patens

International Journal of Molecular Sciences ◽

10.3390/ijms21030975 ◽

2020 ◽

Vol 21 (3) ◽

pp. 975 ◽

Cited By ~ 8

Author(s):

Xiaojun Pu ◽

Lixin Yang ◽

Lina Liu ◽

Xiumei Dong ◽

Silin Chen ◽

...

Keyword(s):

Stress Responses ◽

Physcomitrella Patens ◽

Myb Transcription Factor ◽

Rna Seq ◽

Genome Wide ◽

Terrestrial Environments ◽

Gene Structures ◽

Myb Genes ◽

Myb Proteins ◽

R2r3 Myb

MYB transcription factors (TFs) are one of the largest TF families in plants to regulate numerous biological processes. However, our knowledge of the MYB family in Physcomitrella patens is limited. We identified 116 MYB genes in the P. patens genome, which were classified into the R2R3-MYB, R1R2R3-MYB, 4R-MYB, and MYB-related subfamilies. Most R2R3 genes contain 3 exons and 2 introns, whereas R1R2R3 MYB genes contain 10 exons and 9 introns. N3R-MYB (novel 3RMYB) and NR-MYBs (novel RMYBs) with complicated gene structures appear to be novel MYB proteins. In addition, we found that the diversity of the MYB domain was mainly contributed by domain shuffling and gene duplication. RNA-seq analysis suggested that MYBs exhibited differential expression to heat and might play important roles in heat stress responses, whereas CCA1-like MYB genes might confer greater flexibility to the circadian clock. Some R2R3-MYB and CCA1-like MYB genes are preferentially expressed in the archegonium and during the transition from the chloronema to caulonema stage, suggesting their roles in development. Compared with that of algae, the numbers of MYBs have significantly increased, thus our study lays the foundation for further exploring the potential roles of MYBs in the transition from aquatic to terrestrial environments.

Download Full-text

NtMYB3, an R2R3-MYB from Narcissus, Regulates Flavonoid Biosynthesis

International Journal of Molecular Sciences ◽

10.3390/ijms20215456 ◽

2019 ◽

Vol 20 (21) ◽

pp. 5456 ◽

Cited By ~ 3

Author(s):

Muhammad Anwar ◽

Weijun Yu ◽

Hong Yao ◽

Ping Zhou ◽

Andrew C. Allan ◽

...

Keyword(s):

Transgenic Tobacco ◽

Flavonoid Biosynthesis ◽

Pcr Analysis ◽

Wild Type ◽

Narcissus Tazetta ◽

Over Expression ◽

Qrt Pcr ◽

Red Color ◽

R2r3 Myb ◽

R2r3 Myb Transcription Factors

R2R3-MYB transcription factors play important roles in the regulation of plant flavonoid metabolites. In the current study, NtMYB3, a novel R2R3-MYB transcriptional factor isolated from Chinese narcissus (Narcissus tazetta L. var. chinensis), was functionally characterized. Phylogenetic analysis indicated that NtMYB3 belongs to the AtMYB4-like clade, which includes repressor MYBs involved in the regulation of flavonoid biosynthesis. Transient assays showed that NtMYB3 significantly reduced red pigmentation induced by the potato anthocyanin activator StMYB-AN1 in agro-infiltrated leaves of tobacco. Over-expression of NtMYB3 decreased the red color of transgenic tobacco flowers, with qRT-PCR analysis showing that NtMYB3 repressed the expression levels of genes involved in anthocyanin and flavonol biosynthesis. However, the proanthocyanin content in flowers of transgenic tobacco increased as compared to wild type. NtMYB3 showed expression in all examined narcissus tissues; the expression level in basal plates of the bulb was highest. A 968 bp promoter fragment of narcissus FLS (NtFLS) was cloned, and transient expression and dual luciferase assays showed NtMYB3 repressed the promoter activity. These results reveal that NtMYB3 is involved in the regulation of flavonoid biosynthesis in narcissus by repressing the biosynthesis of flavonols, and this leads to proanthocyanin accumulation in the basal plate of narcissus.

Download Full-text

Faculty Opinions recommendation of The Arabidopsis R2R3 MYB proteins FOUR LIPS and MYB88 restrict divisions late in the stomatal cell lineage.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1028689.341253 ◽

2005 ◽

Author(s):

Alistair Hetherington

Keyword(s):

Cell Lineage ◽

Myb Proteins ◽

R2r3 Myb

Download Full-text

The Evolutionary History of R2R3-MYB Proteins Across 50 Eukaryotes: New Insights Into Subfamily Classification and Expansion

Scientific Reports ◽

10.1038/srep11037 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 39

Author(s):

Hai Du ◽

Zhe Liang ◽

Sen Zhao ◽

Ming-Ge Nan ◽

Lam-Son Phan Tran ◽

...

Keyword(s):

Evolutionary History ◽

History Of ◽

Subfamily Classification ◽

Myb Proteins ◽

R2r3 Myb

Download Full-text

Transcriptional regulation of flavonoid biosynthesis in nectarine (Prunus persica) by a set of R2R3 MYB transcription factors

BMC Plant Biology ◽

10.1186/1471-2229-13-68 ◽

2013 ◽

Vol 13 (1) ◽

pp. 68 ◽

Cited By ~ 126

Author(s):

Daniela Ravaglia ◽

Richard V Espley ◽

Rebecca A Henry-Kirk ◽

Carlo Andreotti ◽

Vanina Ziosi ◽

...

Keyword(s):

Transcriptional Regulation ◽

Transcription Factors ◽

Prunus Persica ◽

Flavonoid Biosynthesis ◽

Myb Transcription Factors ◽

R2r3 Myb ◽

R2r3 Myb Transcription Factors

Download Full-text

Isolation and molecular analysis of two R2R3-MYB genes from the sunflower (Helianthus annuus)

Botany ◽

10.1139/cjb-2013-0071 ◽

2013 ◽

Vol 91 (10) ◽

pp. 731-738 ◽

Cited By ~ 6

Author(s):

Claudio Pugliesi ◽

Mariangela Salvini ◽

Marco Fambrini

Keyword(s):

Amino Acids ◽

Dna Binding ◽

Helianthus Annuus ◽

Functional Domain ◽

Tryptophan Residues ◽

Myb Genes ◽

Myb Proteins ◽

R2r3 Myb ◽

Myb Domain

MYB factors comprise one of the largest family of transcription factors (TFs) characterized by a highly conserved DNA-binding domain: the MYB domain. From the sunflower (Helianthus annuus L.) genome, we have isolated two R2R3-type MYB TFs (Ha-R2R3-MYB1 and Ha-R2R3-MYB2) that show homology with the functional domain of most R2R3-MYB proteins of other species. The R2 (53 amino acids) and R3 (51 amino acids) motifs of the sunflower MYB TFs contain typical amino acids, including a series of highly conserved tryptophan residues, which play a key role in sequence-specific DNA binding. In the MYB domain, both genes (Ha-R2R3-MYB1 and Ha-R2R3-MYB2) exhibit the highly conserved splicing arrangement of three exons and two introns. Using in situ hybridization, a weak level of Ha-R2R3-MYB1 transcription was uniformly spread in shoot apical meristem (SAM), as well as in axillary meristem (AM). By contrast, Ha-R2R3-MYB2 transcription was strongly restricted to a small domain within the boundary zone separating the SAM and the leaf primordia, suggesting that Ha-R2R3-MYB2 may be involved in an early step of AM development.

Download Full-text