水稻Sdr4调控种子休眠的分子机制

种子休眠是水稻的重要农艺性状之一，与种子萌发和穗发芽密切相关，直接影响稻谷的产量与品质。水稻种子休眠数量性状位点Sdr4已被克隆，但其调控水稻种子休眠的分子机制尚不清楚。本项目研究，拟利用酵母双杂交技术筛选与Sdr4互作的转录因子，通过GST Pull-down和Co-IP等实验对Sdr4与候选转录因子间的互作进行验证。对确认互作的转录因子的功能进行分析：通过基因敲除和过量表达分析评估其对种子休眠的调控作用；结合CHIP-seq与差异表达分析，挖掘对种子休眠有调控作用的互作转录因子的下游靶基因；在遗传水平明确Sdr4、互作转录因子及其下游靶基因之间的调控关系。此外，拟利用酵母单杂交、CHIP-qPCR及遗传分析等实验验证OsVP1对Sdr4的直接转录调控。本项目的开展将逐步揭示水稻Sdr4介导的种子休眠调控网络及其分子机制，为相关农作物种子休眠性状的改良提供候选基因和理论支持。

Seed dormancy is one of the important agronomic traits of rice. Seed dormancy is closely related to seed germination and pre-harvest sprouting, which directly affect the yield and quality of rice grain. The quantitative trait locus Seed dormancy 4 (Sdr4) for rice seed dormancy had been cloned, but the molecular mechanism underlying Sdr4-medicated seed dormancy remains to be unclear. In this project, yeast two-hybrid technology will be used to screen transcription factors interacting with Sdr4. In addition, the interaction between the candidate transcription factors and Sdr4 will be confirmed by GST Pull-down and Co-IP. Then we will analyze the functions of the verified transcription factors as follow: gene knockout and overexpression analysis will be employed to estimate their regulation function on seed dormancy; both CHIP-seq and differential expression analysis will be used to mine downstream target genes of the verified transcription factors being able to regulate seed dormancy; we will genetically analyze the regulatory relationship among Sdr4, the transcription factors and the downstream genes. Besides, we will verify the direct transcriptional regulation of rice viviparous-1 (OsVP1) upon Sdr4 by yeast one-hybrid, CHIP-qPCR and genetic analysis. This project will gradually shed light on Sdr4-mediated seed dormancy network and its molecular mechanism in rice. And it will provide candidate genes and theoretical support for the improvement of seed dormancy trait in related crops.