scholarly journals Alternative Splicing of the Basic Helix–Loop–Helix Transcription Factor Gene CmbHLH2 Affects Anthocyanin Biosynthesis in Ray Florets of Chrysanthemum (Chrysanthemum morifolium)

2021 ◽  
Vol 12 ◽  
Author(s):  
Sun-Hyung Lim ◽  
Da-Hye Kim ◽  
Jae-A. Jung ◽  
Jong-Yeol Lee
Keyword(s):  
Transcription Factor ◽  
Alternative Splicing ◽  
Anthocyanin Biosynthesis ◽  
Underlying Mechanism ◽  
Chrysanthemum Morifolium ◽  
Full Length ◽  
Cultivation Conditions ◽  
Helix Loop Helix ◽  
Transcription Factor Genes ◽  
Ray Florets

Chrysanthemum is an important ornamental crop worldwide. Some white-flowered chrysanthemum cultivars produce red ray florets under natural cultivation conditions, but little is known about how this occurs. We compared the expression of anthocyanin biosynthetic and transcription factor genes between white ray florets and those that turned red based on cultivation conditions to comprehend the underlying mechanism. Significant differences in the expression of CmbHLH2 were detected between the florets of different colors. CmbHLH2 generated two alternatively spliced transcripts, designated CmbHLH2Full and CmbHLH2Short. Compared with CmbHLH2Full, CmbHLH2Short encoded a truncated protein with only a partial MYB-interaction region and no other domains normally present in the full-length protein. Unlike the full-length form, the splicing variant protein CmbHLH2Short localized to the cytoplasm and the nucleus and could not interact with CmMYB6. Additionally, CmbHLH2Short failed to activate anthocyanin biosynthetic genes and induce pigment accumulation in transiently transfected tobacco leaves, whereas CmbHLH2Full promoted both processes when simultaneously expressed with CmMYB6. Co-expressing CmbHLH2Full and CmMYB6 also enhanced the promoter activities of CmCHS and CmDFR. Notably, the Arabidopsis tt8-1 mutant, which lacks red pigmentation in the leaves and seeds, could be complemented by the heterologous expression of CmbHLH2Full, which restored red pigmentation and resulted in red pigmentation in high anthocyanin and proanthocyanidin contents in the leaves and seeds, respectively, whereas expression of CmbHLH2Short did not. Together, these results indicate that CmbHLH2 and CmMYB6 interaction plays a key role in the anthocyanin pigmentation changes of ray florets in chrysanthemum. Our findings highlight alternative splicing as a potential approach to modulate anthocyanin biosynthesis in specific tissues.

scholarly journals Key basic helix–loop–helix transcription factor genes Hes1 and Ngn2 are regulated by Pax3 during mouse embryonic development

2008 ◽  
Vol 316 (2) ◽  
pp. 510-523 ◽  
Author(s):  
Hiromichi Nakazaki ◽  
Anvesh C. Reddy ◽  
Barbara L. Mania-Farnell ◽  
Yueh-Wei Shen ◽  
Shunsuke Ichi ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Embryonic Development ◽  
Basic Helix Loop Helix ◽  
Helix Loop Helix ◽  
Transcription Factor Genes

scholarly journals Overexpression of ThMYC4E Enhances Anthocyanin Biosynthesis in Common Wheat

2019 ◽  
Vol 21 (1) ◽  
pp. 137 ◽  
Author(s):  
Shuo Zhao ◽  
Xingyuan Xi ◽  
Yuan Zong ◽  
Shiming Li ◽  
Yun Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Common Wheat ◽  
Anthocyanin Biosynthesis ◽  
Pcr Analysis ◽  
Bhlh Transcription Factor ◽  
Anthocyanin Content ◽  
Metabolome Analysis ◽  
Helix Loop Helix ◽  
Transgenic Lines ◽  
Ethanol Extracts

The basic helix-loop helix (bHLH) transcription factor has been inferred to play an important role in blue and purple grain traits in common wheat, but to date, its overexpression has not been reported. In this study, the bHLH transcription factor ThMYC4E, the candidate gene controlling the blue grain trait from Th. Ponticum, was transferred to the common wheat JW1. The positive transgenic lines displayed higher levels of purple anthocyanin pigments in their grains, leaves and glumes. Stripping the glumes (light treatment) caused white grains to become purple in transgenic lines. RNA-Seq and qRT-PCR analysis demonstrated that the transcript levels of structural genes associated with anthocyanin biosynthesis were higher in transgenic wheat than the wild-type (WT), which indicated that ThMYC4E activated anthocyanin biosynthesis in the transgenic lines. Correspondingly, the anthocyanin contents in grains, roots, stems, leaves and glumes of transgenic lines were higher than those in the WT. Metabolome analysis demonstrated that the anthocyanins were composed of cyanidin and delphinidin in the grains of the transgenic lines. Moreover, the transgenic lines showed higher antioxidant activity, in terms of scavenging DPPH radicals, in the ethanol extracts of their grains. The overexpression of ThMYC4E sheds light on the traits related to anthocyanin biosynthesis in common wheat and provide a new way to improve anthocyanin content.

scholarly journals A subgroup of MYB transcription factor genes undergoes highly conserved alternative splicing in Arabidopsis and rice

2006 ◽  
Vol 57 (6) ◽  
pp. 1263-1273 ◽  
Author(s):  
Jigang Li ◽  
Xiaojuan Li ◽  
Lei Guo ◽  
Feng Lu ◽  
Xiaojie Feng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Alternative Splicing ◽  
Myb Transcription Factor ◽  
Transcription Factor Genes

scholarly journals Whole-transcriptome analysis of differentially expressed genes in the mutant and normal capitula of Chrysanthemum morifolium

2020 ◽  
Author(s):  
Hua Liu ◽  
Chang Luo ◽  
Dongliang Chen ◽  
Yaqin Wang ◽  
Shuang Guo ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Transcriptome Analysis ◽  
Anthocyanin Biosynthesis ◽  
Floral Organ ◽  
Chrysanthemum Morifolium ◽  
Differentially Expressed ◽  
Vegetative Buds ◽  
Ray Florets ◽  
Whole Transcriptome Analysis ◽  
Whole Transcriptome

Abstract Background: Chrysanthemum morifolium is one of the most economically important and popular floricultural crops in the family Asteraceae. Chrysanthemum flowers vary considerably in terms of colors and shapes. However, the molecular mechanism controlling the development of chrysanthemum floral colors and shapes remains an enigma. We analyzed a cut-flower chrysanthemum variety that produces normal capitula composed of ray florets with normally developed pistils and purple corollas and mutant capitula comprising ray florets with green corollas and vegetative buds instead of pistils.Results: We conducted a whole-transcriptome analysis of the differentially expressed genes (DEGs) in the mutant and normal capitula using third-generation and second-generation sequencing techniques. We identified the DEGs between the mutant and normal capitula to reveal important regulators underlying the differential development. Many transcription factors and genes related to the photoperiod and GA pathways, floral organ identity, and the anthocyanin biosynthesis pathway were differentially expressed between the normal and mutant capitula. A qualitative analysis of the pigments in the florets of normal and mutant capitula indicated anthocyanins were synthesized and accumulated in the florets of normal capitula, but not in the florets of mutant capitula. These results provide clues regarding the molecular basis of the replacement of Chrysanthemum morifolium ray florets with normally developed pistils and purple corollas with mutant ray florets with green corollas and vegetative buds. Additionally, the study findings will help to elucidate the molecular mechanisms underlying floral organ development and contribute to the development of techniques for studying the regulation of flower shape and color, which may enhance chrysanthemum breeding.Conclusions: The whole-transcriptome analysis of DEGs in mutant and normal C. morifolium capitula described herein indicates the anthocyanin deficiency of the mutant capitula may be related to the mutation that replaces ray floret pistils with vegetative buds. Moreover, pistils may be required for the anthocyanin biosynthesis in the corollas of chrysanthemum ray florets.

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