石山苣苔属花器官形态分化和物种适应性进化的分子机制研究

本项目首先开展控制这些花部形态性状的CYC类PCYC及其相关目标基因PRAD和PcyclinD3a/b以及腹特性PDIV基因表达模式的比较研究，分析表达模式的时空分化和这些形态变异的相关关系以及它们在调控关系上可能发生的变化；然后，通过对PCYC及其相关基因的特异转基因功能分析试图发现它们在蛋白质和启动子可能的功能变化同表达模式与形态分化的相关关系和作用途径，并进一步经蛋白-DNA结合作用分析PCYC基因对其目标基因PRAD和PcyclinD3a/b调控过程中可能发生的变化所产生的形态变异及其作用机制。经全面的综合分析，本项目以期揭示石山苣苔属两侧-辐射对称花分支花器官形态变异和物种适应性分化过程中花对称性主控基因PCYC及其目标基因的分子进化机制。该项目研究结果对进一步理解适应性物种形成与进化具有重要的理论意义。

Selecting species of bilateral-radial flower lineage in Petrocodon as materials (four species and one variety), we will probe into the molecular mechanism of floral morphological differentiation species adaptive evolutionary under extreme Karst geographic and topographic condition. The species in the bilateral-radial flower lineage specifically distributed in the limestone areas of southwestern China are characteristic of extreme range of floral morphological variation co-evolved with the change of insect pollination model. We first employ real-time PCR and in situ hybridization methods to conduct comparative expression pattern analyses of the specific controlling factors of the these floral morphological characters, i.e. PCYCs and their possible targets PRAD and PcyclinD3a/b, in the representative species of this lineage, aiming at understanding correlation of the floral variation and related gene expression. Then, we will further carry out a series of specific transgenic functional studies of PCYCs and related genes. Furthermore, this project will search and detect the binding site of PCYC proteins in the 5' upstream regulatory region of PCYC's possible targets PRAD and PcyclinD3a/b and further conduct a series of protein-DNA interaction analyses, including Electrophoresis Mobility Shift Assays (EMSAs) in vitro and Chromatin immunoprecipitation (ChIP) in vivo, aiming to detect the possible molecular changes in the regulatory network of PCYCs and their targets. This project aims to reveal the molecular evolutionary mechanism underlying the floral morphological variation and the adaptive species differentiation of the bilateral-radial flower lineage in Petrocodon under the extreme Karst geographic and topographic condition.