两侧对称花的起源是被子植物辐射分化过程中的一个关键创新事件。目前，人们对于花对称性调控通路的认识主要来自于模式植物金鱼草，而花对称性调控网络是如何进化进而产生不同支系的两侧对称花，人们还知之甚少。因此，选择一个更为原始的代表种开展相关研究就显得尤为重要。本项目以苦苣苔科斑叶草作为模式系统，针对花对称性基因CYCLOIDEA（CYC）、RADIALIS（RAD）以及DIVARICATA（DIV）开展一系列研究。我们首先采用实时定量PCR和原位杂交方法分析这些基因的表达模式，然后凭借过量表达、基因敲除、功能互补等转基因技术研究基因的功能，最后通过凝胶阻滞、染色质免疫沉淀以及瞬时基因表达实验探讨基因间的调控关系。通过以上研究，本项目旨在全面揭示斑叶草两侧对称花形成的调控网络。由于斑叶草比金鱼草更为原始，因此，本项目的研究结果将对深入理解唇形目两侧对称花调控网络的起源与演化具有重要意义。

As a key innovation in angiosperm evolution, the origin of zygomorphic (bilateral symmetric) flowers has been comprehensively addressed in the classic model system Antirrhinum majus. However, the regulatory pathway underlying floral zygomorphy is still ambiguous outside A. majus. Therefore, selecting a more ancient representative outside the model system will be particularly important to understand the origin and evolution of zygomorphic flowers. This project selects Chirita pumila (Gesneriaceae, one of the most basal groups in Lamiales) as a model to explore the regulatory network underlying zygomorphic flowers by focusing on floral symmetry genes including CYCLOIDEA (CYC), RADIALIS (RAD) and DIVARICATA (DIV). We will first conduct real-time quantitative PCR and RNA in situ hybridization to analyze the expression patterns of these genes. Then, we will survey the function of these genes in floral symmetry establishment by utilizing several kinds of transgenic methods, including over-expression under the control of the CAMV 35S constitutive promoter, gene knock-down by using the chimeric repressor silencing technology (CRES-T), as well as gain-of-function by rescuing the actinomorphic flower mutants. Furthermore, we will perform in vitro electrophoresis mobility shift assays (EMSA) and in vivo chromatin immunoprecipitation (ChIP) to detect the protein–DNA interactions, and perform transient gene expression to analyze the function of related cis-elements in transcription activation or repression. By adopting the above-mentioned methods, this project aims to comprehensively investigate the function and regulatory network of floral symmetry genes in C. pumila. Finally, through comparative analysis between C. pumila and A. majus, we will probe into the origin and evolution of the regulatory network controlling zygomorphic flowers in Lamiales.