研究种子休眠的分子机制有助于解决穗发芽过多、出苗率不高和杂草防治困难等农业生产问题。REDUCED DORMANCY 5 （RDO5）是重要的种子休眠调控基因，编码一个在种子中特异表达且没有磷酸酶活性的2C型蛋白磷酸酶；但它调控种子休眠的分子机制却不清楚。本项目前期研究发现RDO5可能通过GA合成途径调控种子休眠，并发现RDO5可以与磷酸酶RDIP1和激酶RDIK1在体内形成蛋白复合体。进一步研究发现RDO5影响RDIP1和RDIK1的磷酸化强度，并依赖RDIP1及其同源基因RDIP2调控种子休眠。本项目拟对RDO5蛋白复合体中成员的时空表达模式，遗传学上下游关系，蛋白质磷酸化水平，以及激酶、磷酸酶活性等方面展开详细研究，解析它们调控种子休眠的分子机制，并建立与GA合成途径的联系。本项目将丰富种子休眠的分子调控网络，增加人们对PP2C功能范畴的认知，同时为分子育种提供新的基因资源。

Study on the molecular mechanism of seed dormancy is conducive to solve the agricultural-related problems such as high rates of pre-harvest sprouting, low rates of seedling emergence and difficulty of weed control. REDUCED DORMANCY 5 (RDO5) is an important dormancy regulating gene, which is specifically expressed in seed and encodes a type 2C protein phosphatase that has no phosphatase activity. However, the molecular mechanism by which it regulates seed dormancy is still unclear. The preliminary study of this project found that RDO5 might regulate seed dormancy through GA biosynthesis pathway, and found that RDO5 could form protein complex with phosphatase RDIP1 and kinase RDIK1 in vivo. Further studies revealed that RDO5 affected the phosphorylation intensity of RDIP1 and RDIK1, and regulated seed dormancy depending on the function of RDIP1 and its homologous gene RDIP2. This project will carry out a serious of detailed study on the members of RDO5 protein complex, including their spatial and temporal expression patterns, their upstream and downstream relationship of genetics, their protein phosphorylation levels, as well as their activities of kinases or phosphatases. It will finally figure out the molecular mechanism of the protein complex regulating seed dormancy and establish a connection with GA biosynthesis pathway. This project will enrich the molecular regulatory network of seed dormancy, increase the recognition of the functional category of PP2C, and provide new genetic resources for molecular breeding.