Key Laboratory of Plant Resources/Beijing Botanical Garden, Institute of Botany, the Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Plant Cell Physiol. 2019 Mar 1;60(3):599-611. doi: 10.1093/pcp/pcy232.
Flower color patterns play critical roles in plant-pollinator interactions and represent one of the most common adaptations during angiosperm evolution. However, the molecular mechanisms underlying flower color pattern formation are less understood in non-model organisms. The aim of this study was to identify genes involved in the formation of petal blotches in tree peony (Paeonia suffruticosa) through transcriptome profiling and functional experiments. We identified an R2R3-MYB gene, PsMYB12, representing a distinct R2R3-MYB subgroup, with a spatiotemporal expression pattern tightly associated with petal blotch development. We further demonstrated that PsMYB12 interacts with a basic helix-loop-helix (bHLH) and a WD40 protein in a regulatory complex that directly activates PsCHS expression, which is also specific to the petal blotches. Together, these findings advance our understanding of the molecular mechanisms of pigment pattern formation beyond model plants. They also benefit molecular breeding of tree peony cultivars with novel color patterns and promote germplasm innovation.
花的颜色图案在植物与传粉者的相互作用中起着至关重要的作用，是被子植物进化过程中最常见的适应之一。然而，在非模式生物中，花颜色图案形成的分子机制还不太清楚。本研究通过转录组分析和功能实验，旨在鉴定与牡丹（Paeonia suffruticosa）花瓣斑点形成有关的基因。我们鉴定了一个 R2R3-MYB 基因，PsMYB12，它代表了一个独特的 R2R3-MYB 亚群，具有与花瓣斑点发育紧密相关的时空表达模式。我们进一步证明，PsMYB12 在一个调节复合物中与一个碱性螺旋-环-螺旋（bHLH）和一个 WD40 蛋白相互作用，该复合物直接激活 PsCHS 的表达，这也特异性地存在于花瓣斑点中。这些发现增进了我们对色素模式形成的分子机制的理解，超越了模式植物。它们还有利于具有新颜色图案的牡丹品种的分子育种，并促进了种质创新。
