SiAMP1调控谷子籽粒发育的功能验证和机理分析

Grain size is one of the most important factors determining crop yield. Identify key genes and the regulatory mechanisms that control this quantitative trait is predominant for crops genetic improvement. Setaria italica is now developing as a promising model for functional genomics in Panicoideae, especially for research of drought tolerance and C4 photosynthesis. Our research team screened the amp1 mutant from a library of EMS induced mutants, which has smaller grains compared to wild type. We isolated the candidate gene SiAMP1 by an integrative method of map-based clone and high-throughput sequencing. Based on these results, we will employ an integrative approach of plant physiology, molecular biology, genetics, and bioinformatics in this study, to investigate the dynamic morphology and physiological responses of the amp1 mutant at different development phases. Then, we focus on the functional mechanism of SiAMP1 gene on grain development and the isolation of its interacting proteins to establish a genetic regulatory network of SiAMP1 on grain development. Our research may pave a new way for understanding the molecular mechanism of grain development, and provide a substantial basis and resource for genetic improvement of crops.

籽粒大小是作物高产育种的关键性状，而相关基因发掘及调控机理解析是性状改良的基础。谷子作为新兴模式植物，是研究C4禾谷类作物功能基因的理想植物材料。本团队从谷子EMS突变体库中鉴定出一个籽粒变小的突变体，图位克隆分离得到目标基因SiAMP1。初步研究表明，该基因可能通过一个新的途径参与调控谷子籽粒发育性状。本研究拟首先对突变体表型性状进行深入调查，系统分析其表型形成的形态学及细胞学基础；然后对SiAMP1进行转基因验证及功能分析，解析其作用的分子机制并鉴定互作蛋白，初步建立SiAMP1调控谷子籽粒发育的遗传网络，为作物产量性状遗传改良提供基因资源和理论基础。

种子及穗的大小与是农作物产量构成的重要因素。谷子因其具备模式植物的特性，是发掘作物籽粒发育调控基因的优异材料。本项目团队利用化学诱变的方法创制了谷子籽粒发育突变体，通过将图位克隆结合高通量测序分离得到目标基因SiAMP1。形态学及细胞学观察发现突变体籽粒发育异常主要是细胞数量变少导致的。利用传统分子生物学实验结合高通量测序及蛋白组技术对SiAMP1基因进行了深入的基因功能分析，研究发现该基因通过ABA途径参与调控谷子籽粒发育等性状。目的基因的单倍型分析及转基因功能验证表明，SiAMP1能够影响谷子、拟南芥及水稻的籽粒大小和千粒重，具有增产潜力。相关成果形成国家发明专利1项，发表论文6篇。课题实施过程培养研究生3人，申请人受邀作大会报告2次，取得了较好的学术影响。本项目为作物产量性状遗传改良提供了基因资源和理论基础。