Identification of Two Novel R2R3-MYB Transcription factors, PsMYB114L and PsMYB12L, Related to Anthocyanin Biosynthesis in Paeonia suffruticosa

作者：Xinpeng Zhang, Zongda Xu, Xiaoyan Yu, Lanyong Zhao, Mingyuan Zhao, Xu Han, Qi Shuai · 发表于：International Journal of Molecular Sciences · 年份：2019 · DOI：10.3390/ijms20051055 · 被引用次数：70 · 研究领域：Plant Gene Expression Analysis、Plant biochemistry and biosynthesis、Phytochemicals and Antioxidant Activities

Flower color is a charming phenotype with very important ornamental and commercial values. Anthocyanins play a critical role in determining flower color pattern formation, and their biosynthesis is typically regulated by R2R3-MYB transcription factors (TFs). Paeonia suffruticosa is a famous ornamental plant with colorful flowers. However, little is known about the R2R3-MYB TFs that regulate anthocyanin accumulation in P. suffruticosa. In the present study, two R2R3-MYB TFs, namely, PsMYB114L and PsMYB12L, were isolated from the petals of P. suffruticosa ‘Shima Nishiki’ and functionally characterized. Sequence analysis suggested that PsMYB114L contained a bHLH-interaction motif, whereas PsMYB12L contained two flavonol-specific motifs (SG7 and SG7-2). Subsequently, the in vivo function of PsMYB114L and PsMYB12L was investigated by their heterologous expression in Arabidopsis thaliana and apple calli. In transgenic Arabidopsis plants, overexpression of PsMYB114L and of PsMYB12L caused a significantly higher accumulation of anthocyanins, resulting in purple-red leaves. Transgenic apple calli overexpressing PsMYB114L and PsMYB12L also significantly enhanced the anthocyanins content and resulted in a change in the callus color to red. Meanwhile, gene expression analysis in A. thaliana and apple calli suggested that the expression levels of the flavonol synthase (MdFLS) and anthocyanidin reductase (MdANR) genes were significantly downregulated and the dihydroflavonol 4-reductase (At...