Comparative Transcriptome Analysis Revealed Two Alternative Splicing bHLHs Account for Flower Color Alteration in Chrysanthemum
‘Jimba’ is a white chrysanthemum cultivar, which occasionally and spontaneously produces red flower petals under natural cultivation due to cyanidin-based anthocyanin accumulation. To investigate the underlying mechanism of this process, a comparative transcriptome was analyzed between white and tur...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/23/12769 |
| Summary: | ‘Jimba’ is a white chrysanthemum cultivar, which occasionally and spontaneously produces red flower petals under natural cultivation due to cyanidin-based anthocyanin accumulation. To investigate the underlying mechanism of this process, a comparative transcriptome was analyzed between white and turning red ‘Jimba’. The structural and regulatory genes of anthocyanin pathway were significantly up-regulated in turning red ‘Jimba’. Among them, two alternative splicings, <i>CmbHLH2</i> and <i>CmbHLH2.1</i>, showed the most significantly up-regulated in turning red tissue. Transiently over-expressed <i>35S::CmMYB6-CmbHLH2</i> strongly induced anthocyanin accumulation in ‘Jimba’ flower petals, while moderate amount of anthocyanin was detected when over-expressed <i>35S::CmMYB6-CmbHLH2.1</i>. Both CmbHLH2 and CmbHLH2.1 could interact with CmMYB6 to activate <i>CmDFR</i> promoter according to Yeast two-hybrid and dual-luciferase assay. Moreover, CmMYB6-CmbHLH2 but not CmMYB6-CmbHLH2.1 could activate the <i>CmbHLH2</i> promoter to provide positive feedback loop regulation. Taken together, it suggested that both CmbHLH2 and CmbHLH2.1 involved in regulation flower color alteration in turning red ‘Jimba’, and CmbHLH2 played a predominant role in this process. |
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| ISSN: | 1661-6596 1422-0067 |