The Conserved and Particular Roles of the R2R3-MYB Regulator FhPAP1 from Freesia hybrida in Flower Anthocyanin Biosynthesis
- 1 July 2020
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant and Cell Physiology
- Vol. 61 (7), 1365-1380
- https://doi.org/10.1093/pcp/pcaa065
Abstract
Anthocyanin biosynthesis is mainly controlled by MYB-bHLH-WD40 (MBW) complexes that modulate the expression of anthocyanin biosynthetic genes (ABGs). The MYB regulators involved in anthocyanin biosynthesis arose early during plant evolution and thusmight function divergently in different evolutionary lineages. Although the anthocyanin-promoting R2R3-MYB regulators in eudicots have been comprehensively explored, little consensus has been reached about functional discrepancies versus conservation among MYB regulators from different plant lineages. Here, we integrated transcriptome analysis, gene expression profiles, gain-of- function experiments and transient protoplast transfection assays to functionally characterize the monocot Freesia hybrida anthocyanin MYB regulator gene FhPAP1, which showed correlations with late ABGs. FhPAP1 could activate ABGs as well as TT8-clade genes FhTT8L, AtTT8 and NtAN1 when overexpressed in Freesia, Arabidopsis and tobacco, respectively. Consistently, FhPAP1 could interact with FhTT8L and FhTTG1 to form the conserved MBW complex and shared similar target genes with its orthologs from Arabidopsis. Most prominently, FhPAP1 displayed higher transactivation capacity than its homologs in Arabidopsis and tobacco, which was instantiated in its powerful regulation on ABGs. Moreover, we found that FhPAP1 might be the selected gene during the domestication and rapid evolution of the wild Freesia species to generate intensive flower pigmentation. These results showed that while the MBW complex was highly evolutionarily conserved between tested monocot and core eudicot plants, participating MYB regulators showed functional differences in transactivation capacity according to their activation domain and played important roles in the flower coloration domestication and evolution of angiosperms.Keywords
Funding Information
- National Natural Science Foundation of China (31900252, 31972445)
- China Postdoctoral Science Foundation-funded (2018M641761)
- Department of Science and Technology of Jilin Province (20190201299JC, 20190303095SF)
- Programme for Introducing Talents to Universities (B07017)
- Fundamental Research Fund for the Central Universities
This publication has 73 references indexed in Scilit:
- New insights into the regulation of anthocyanin biosynthesis in fruitsTrends in Plant Science, 2013
- Regulation of flavonoid biosynthesis involves an unexpected complex transcriptional regulation of TT8 expression, in ArabidopsisNew Phytologist, 2013
- The evolution of phenylpropanoid metabolism in the green lineageCritical Reviews in Biochemistry and Molecular Biology, 2012
- Plant Specialized Metabolism: the Easy and the HardJournal of Integrative Plant Biology, 2010
- An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in RosaceaeBMC Plant Biology, 2010
- Comprehensive analysis of single-repeat R3 MYB proteins in epidermal cell patterning and their transcriptional regulation in ArabidopsisBMC Plant Biology, 2008
- TheArabidopsisTranscription Factor MYB77 Modulates Auxin Signal TransductionPlant Cell, 2007
- Differential regulation of closely related R2R3‐MYB transcription factors controls flavonol accumulation in different parts of the Arabidopsis thaliana seedlingThe Plant Journal, 2007
- Aux/IAA Proteins Contain a Potent Transcriptional Repression DomainPlant Cell, 2004
- Analysis of Relative Gene Expression Data Using Real-Time Quantitative PCR and the 2−ΔΔCT MethodMethods, 2001