外源生长素类物质PIC介导ABA调控百合体细胞胚发生的分子机制

百合产业中的品种性状遗传改良和种球优质繁育是国际性难题，体细胞胚发生是最有希望解决上述难题的重要再生途径。目前植物体胚发生的分子机制尚未全面解析。本项目在探明生长素类物质PIC对百合体细胞胚程序性启动的先决作用、初步证实高水平内源ABA与体胚发生密切相关的基础上，以参与调控ABA合成的WRKY转录因子为研究切入点，聚焦于体胚发生初期体细胞胚性获得这一关键环节，利用过表达及CRISPR-Cas9基因编辑等技术进行LpWRKY基因的功能验证，明确LpWRKY在百合胚性细胞形成中的关键作用；借助酵母单杂交、ChIP-PCR及EMSA等技术，明确目标LpWRKY与生长素信号和ABA合成途径的互作因子。通过探究WRKY与生长素信号转导和ABA生物合成的关系，揭示外源生长素调控百合胚性细胞形成的分子机制。研究结果将突破百合种苗繁殖和基因工程育种的瓶颈，为全面解析植物体胚发生的分子机理提供新的阐释。

The genetic improvement of cultivar traits and the propagation of high-quality bulbs in Lilium industry are international thorny problems. And somatic embryogenesis is the most promising way to solve the above problems. At present, the molecular mechanism of somatic embryogenesis in plants has not been clearly elucidated. This project is on the basis that auxin-like substance PIC has been proved to be the prerequisite for programmed initiation of somatic embryo and high levels of endogenous ABA has been preliminary confirmed that was closely related to somatic embryogenesis in Lilium in our previous research. WRKY, which participate in the regulation of ABA synthesis, is selected as the breakthrough point. The critical phase of embryogenic capacity acquisition in early stage of somatic embryogenesis is focused on. The technologies both overexpression and CRISPR-Cas9 will be applied to verify the function of LpWRKY in the embryogenic cell formation in Lilium. By the means of yeast one-hybrid, ChIP-PCR as well as EMSA, the interaction factors of LpWRKY both in the auxin signaling pathway and in the ABA synthesis pathway will be illustrated. By exploring whether WRKY is the connection between Auxin signaling and ABA biosynthesis, the molecular mechanism of exogenous auxin regulating embryogenic cell formation in Lilium will be revealed. The results in this project will break through the bottleneck of bulblets propagation and genetic engineering breeding in Lilium industry, and the new possible interpretation about the molecular mechanism of somatic embryogenesis in the plants will be provided.