scholarly journals Genome-Wide Characterization and Analysis of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Fig (Ficus carica L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Miaoyu Song ◽  
Haomiao Wang ◽  
Zhe Wang ◽  
Hantang Huang ◽  
Shangwu Chen ◽  
...  

The basic helix–loop–helix (bHLH) transcription factor family is the second largest transcription factor family in plants, and participates in various plant growth and development processes. A total of 118 bHLH genes were identified from fig (Ficus carica L.) by whole-genome database search. Phylogenetic analysis with Arabidopsis homologs divided them into 25 subfamilies. Most of the bHLHs in each subfamily shared a similar gene structure and conserved motifs. Seventy-two bHLHs were found expressed at fragments per kilobase per million mapped (FPKM) > 10 in the fig fruit; among them, 15 bHLHs from eight subfamilies had FPKM > 100 in at least one sample. bHLH subfamilies had different expression patterns in the female flower tissue and peel during fig fruit development. Comparing green and purple peel mutants, 13 bHLH genes had a significantly different (≥ 2-fold) expression. Light deprivation resulted in 68 significantly upregulated and 22 downregulated bHLH genes in the peel of the fruit. Sixteen bHLH genes in subfamily III were selected by three sets of transcriptomic data as candidate genes related to anthocyanin synthesis. Interaction network prediction and yeast two-hybrid screening verified the interaction between FcbHLH42 and anthocyanin synthesis-related genes. The transient expression of FcbHLH42 in tobacco led to an apparent anthocyanin accumulation. Our results confirm the first fig bHLH gene involved in fruit color development, laying the foundation for an in-depth functional study on other FcbHLH genes in fig fruit quality formation, and contributing to our understanding of the evolution of bHLH genes in other horticulturally important Ficus species.

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2721
Author(s):  
Chao Tan ◽  
Huilei Qiao ◽  
Ming Ma ◽  
Xue Wang ◽  
Yunyun Tian ◽  
...  

The basic helix-loop-helix (bHLH) transcription factor family is one of the largest transcription factor families in plants and plays crucial roles in plant development. Melon is an important horticultural plant as well as an attractive model plant for studying fruit ripening. However, the bHLH gene family of melon has not yet been identified, and its functions in fruit growth and ripening are seldom researched. In this study, 118 bHLH genes were identified in the melon genome. These CmbHLH genes were unevenly distributed on chromosomes 1 to 12, and five CmbHLHs were tandem repeat on chromosomes 4 and 8. There were 13 intron distribution patterns among the CmbHLH genes. Phylogenetic analysis illustrated that these CmbHLHs could be classified into 16 subfamilies. Expression patterns of the CmbHLH genes were studied using transcriptome data. Tissue specific expression of the CmbHLH32 gene was analysed by quantitative RT-PCR. The results showed that the CmbHLH32 gene was highly expressed in female flower and early developmental stage fruit. Transgenic melon lines overexpressing CmbHLH32 were generated, and overexpression of CmbHLH32 resulted in early fruit ripening compared to wild type. The CmbHLH transcription factor family was identified and analysed for the first time in melon, and overexpression of CmbHLH32 affected the ripening time of melon fruit. These findings laid a foundation for further study on the role of bHLH family members in the growth and development of melon.


2020 ◽  
Vol 61 (4) ◽  
pp. 826-837 ◽  
Author(s):  
Yang Li ◽  
Pengbo Xu ◽  
Guanqun Chen ◽  
Jun Wu ◽  
Zhongchi Liu ◽  
...  

Abstract Anthocyanin accumulation is transcriptionally regulated by the MYB–bHLH–WD40 complex. Light is indispensable for anthocyanin accumulation, and light-inducible MYB and HY5 were considered to promote anthocyanin accumulation in many fruits. Whether and how light-inducible bHLH transcription factor and HY5 regulate anthocyanin synthesis in strawberry is unknown. In this study, we identified a bHLH transcription factor, FvbHLH9, which was induced by light as well as FvHY5, and found that, similar to FvHY5, the transient overexpression and interference FvbHLH9 in strawberry fruits can promote and decrease anthocyanin accumulation, respectively, indicating FvbHLH9 functions as a positive regulator of anthocyanin biosynthesis. Furthermore, we confirmed that both FvHY5 and FvbHLH9 specifically bind to the promoter region of some key enzyme genes, including FvDFR, and the expression of FvDFR was activated through the heterodimer formation between FvHY5 and FvbHLH9. Finally, we confirmed that FvbHLH9-promoted anthocyanin accumulation is dependent on HY5–bHLH heterodimerisation in Arabidopsis. Our findings provide insights into a mechanism involving the synergistic regulation of light-dependent coloration and anthocyanin biosynthesis via a HY5–bHLH heterodimer formed by the interaction of FvHY5 and FvbHLH9 in strawberry fruits.


2020 ◽  
Author(s):  
Selinge Bai ◽  
Chao Tan ◽  
Yunyun Tian ◽  
Ming Ma ◽  
Agula Hasi

Abstract Background: The basic helix-loop-helix (bHLH) transcription factor family is one of the largest transcription factor families in plants, and plays crucial roles in plant development. Melon is one of an important horticulture plants, and is an attractive model plant for studying fruit ripening. However, the bHLH gene family of melon has not been identified yet, and functions in fruit growth and ripening are seldom researched. Results: In this study, 118 bHLH genes were identified in the genome of melon. Phylogenetic analysis illustrated that these CmbHLHs could be classified into 16 subfamilies. Intron distribution pattern analysis of bHLH domain found 13 intron distribution patterns in CmbHLHs. CmbHLH genes were unevenly distributed on chromosomes 1 to 12 of the melon genome, and five CmbHLH s were tandem repeat on chromosomes 4 and 8. Expression characters of CmbHLH genes were studied using the transcriptome data. Tissue analysis of indicated CmbHLH32 high expressed in female flowers and early fruit growth stage. Transgenic plant lines of overexpression of CmbHLH32 were constructed, and overexpression of CmbHLH32 result in early fruit ripening compared to the wild type fruit. Conclusions: The bHLH transcription factor family was identified and analyzed for the first time in the melon, overexpression of CmbHLH32 will affect the ripening time of melon fruit, these findings laid a theoretical foundation for further study on the role of bHLH family members in the growth and development of melon .


2020 ◽  
Vol 145 (2) ◽  
pp. 131-140
Author(s):  
Xiaoying Dou ◽  
Jinrong Bai ◽  
Huan Wang ◽  
Ying Kong ◽  
Lixin Lang ◽  
...  

Anthocyanins are major pigments responsible for the color of lily (Lilium sp.) flowers. Anthocyanin synthesis is part of the flavonoid metabolic pathway. Numerous transcription factors, including R2R3-MYBs, basic helix-loop-helix (bHLH), and tryptophan–aspartic acid repeat (also known as WD40 or WD repeat) proteins, known to regulate flavonoid biosynthesis have been identified in various plant species. However, there is limited information available on WD repeat proteins in lilies. In this study, we identified a WD repeat gene in the Oriental hybrid lily ‘Sorbonne’ (Lilium hybrid WD repeat, LhWDR). LhWDR contains no introns, and has a 1100–base pair open reading frame, encoding a putative protein of 370 amino acids. LhWDR was found to be localized in the cytoplasm of transgenic Arabidopsis thaliana root cells. Expression patterns of LhWDR in different organs and at different periods of lily tepal growth revealed that the expression levels of this gene are closely associated with anthocyanin accumulation. A yeast two-hybrid assay demonstrated that full-length LhWDR interacts with the 420 N-terminal amino acids of Lilium hybrid bHLH2. Interestingly, overexpression of LhWDR in A. thaliana led to an upregulation of the dihydroflavonol 4-reductase gene, which is an important structural gene downstream of the anthocyanin pathway. These results indicate that the WD repeat protein LhWDR might interact with a bHLH transcription factor to regulate anthocyanin biosynthesis.


Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 346 ◽  
Author(s):  
Qianqian Shi ◽  
Xi Li ◽  
Jiangtao Du ◽  
Xingang Li

The basic helix–loop–helix (bHLH) family is an important transcription factor for eukaryotes and is involved in a wide range of biological activities. Among these, bHLH can interaction with WD repeat (WD40 or WDR) and V-myb avian myeloblastosis viral oncogene homolog (MYB) form a ternary complex to promote the efficient synthesis of anthocyanins. In this study, a total of 138 jujube bHLH (ZjbHLH) family members were screened from the transcriptome of the two jujube cultivars, ‘Junzao’ (JZ) and ‘Tailihong’ (TLH). Of these, 95 ZjbHLH genes were mapped to 12 chromosomes. A phylogenetic tree was constructed using 27 arabidopsis bHLH (AtbHLH) protein sequences of Arabidopsis thaliana (L.) Heynh. and 138 ZjbHLH protein sequences of jujube. The results show that the ZjbHLH family of jujube can be divided into 12 subfamilies. The three candidate genes, ZjGL3a, ZjGL3b and ZjTT8, related to anthocyanin synthesis, were classified into subgroup III. Meanwhile, ZjGL3a, ZjGL3b and ZjTT8 have high homology with the bHLH transcription factors involved in anthocyanin synthesis in other plants. In addition, it was found that the jujube ZjbHLH transcript family showed changing patterns of expression during fruit development. The relative expression levels of ZjGL3a, ZjGL3 and ZjTT8 were consistent with the changes of the anthocyanin contents in the two jujube cultivars examined. To better understand the anthocyanin synthesis pathway involved in ZjbHLH, a regulatory pathway model for anthocyanin synthesis was constructed. This model involves the processes of anthocyanin signal transduction, synthesis and transport.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ming Li ◽  
Lei Sun ◽  
Hong Gu ◽  
Dawei Cheng ◽  
XiZhi Guo ◽  
...  

AbstractAs one of the largest transcription factor family, basic helix-loop-helix (bHLH) transcription factor family plays an important role in plant metabolism, physiology and growth. Berry color is one of the important factors that determine grape quality. However, the bHLH transcription factor family’s function in anthocyanin synthesis of grape berry has not been studied systematically. We identified 115 bHLH transcription factors in grape genome and phylogenetic analysis indicated that bHLH family could be classified into 25 subfamilies. First, we screened six candidate genes by bioinformatics analysis and expression analysis. We found one of the candidate genes VdbHLH037 belonged to III (f) subfamily and interacted with genes related to anthocyanin synthesis through phylogenetic analysis and interaction network prediction. Therefore, we speculated that VdbHLH037 participated in the anthocyanin synthesis process. To confirm this, we transiently expressed VdbHLH037 in grape and Arabidopsis transformation. Compared with the control, transgenic materials can accumulate more anthocyanins. These results provide a good base to study the function of the VdbHLH family in anthocyanin synthesis of grape berry.


2021 ◽  
Vol 22 (4) ◽  
pp. 1622
Author(s):  
Yanyan Wang ◽  
Zefeng Zhai ◽  
Yueting Sun ◽  
Chen Feng ◽  
Xiang Peng ◽  
...  

B-BOX proteins are zinc finger transcription factors that play important roles in plant growth, development, and abiotic stress responses. In this study, we identified 15 PavBBX genes in the genome database of sweet cherry. We systematically analyzed the gene structures, clustering characteristics, and expression patterns of these genes during fruit development and in response to light and various hormones. The PavBBX genes were divided into five subgroups. The promoter regions of the PavBBX genes contain cis-acting elements related to plant development, hormones, and stress. qRT-PCR revealed five upregulated and eight downregulated PavBBX genes during fruit development. In addition, PavBBX6, PavBBX9, and PavBBX11 were upregulated in response to light induction. We also found that ABA, BR, and GA3 contents significantly increased in response to light induction. Furthermore, the expression of several PavBBX genes was highly correlated with the expression of anthocyanin biosynthesis genes, light-responsive genes, and genes that function in multiple hormone signaling pathways. Some PavBBX genes were strongly induced by ABA, GA, and BR treatment. Notably, PavBBX6 and PavBBX9 responded to all three hormones. Taken together, BBX proteins likely play major roles in regulating anthocyanin biosynthesis in sweet cherry fruit by integrating light, ABA, GA, and BR signaling pathways.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kaijie Zheng ◽  
Xutong Wang ◽  
Yating Wang ◽  
Shucai Wang

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.


Botany ◽  
2013 ◽  
Vol 91 (10) ◽  
pp. 722-730 ◽  
Author(s):  
Helen H. Tai ◽  
Claudia Goyer ◽  
Agnes M. Murphy

MYB and bHLH are large transcription factor families with largely uncharacterized biological functions. The patterns of expression of 42 MYB and 58 bHLH transcription factor genes were examined in potato clones that were demonstrated to have variation in anthocyanin intensity and common scab resistance to assess their possible involvement in regulating these traits. The control of expression of biosynthetic enzymes in regulation of anthocyanin intensity was also evaluated. The dihydroflavonol 4-reductase (DFR) gene, a key enzyme in the pathway, had the highest correlation with gene expression and anthocyanin intensity (quantified as levels of anthocyanidins). Expression of five uncharacterized MYB and three bHLH genes was also highly correlated with anthocyanin intensity, suggesting that they could be regulators of biosynthetic enzyme gene expression. The same potato clones were also demonstrated to have variation in resistance to Streptomyces scabiei, the causal pathogen of common scab in potato. Correlation analysis was used to show that anthocyanin intensity was not associated with common scab resistance. However, common scab resistance was correlated with expression of another two MYB and three bHLH genes, indicating that they might be involved in the regulation of the defense response of potato against the common scab pathogen.


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