RWP-RK是植物中一类新的转录因子，在玉米、水稻等作物中的生物学功能还没有报道。在前期工作中，通过图位克隆的方法克隆一个RWP-RK家族的转录因子基因OS1，该基因突变以后影响玉米籽粒胚和胚乳的发育。表达分析发现，OS1基因受到低浓度氮的诱导表达和高浓度氮的抑制表达。该家族在玉米B73基因组中有15个成员，利用CRISPR/Cas9技术对该家族的另一个成员ZmRKD1敲除发现，zmrkd1突变体与os1突变体在籽粒上有部分表型相似。本项目将对OS1和ZmRKD1两个基因的功能开展深入研究，利用RNA-seq和原位杂交技术明确两个基因在籽粒不同时期和部位的表达变化规律；通过构建双突变体，研究两个基因之间的遗传调控关系；利用Chip-seq和CRISPR/Cas9技术确定两个基因所调控的下游靶基因，阐明两个基因和氮之间的关系以及在玉米籽粒发育过程中的分子调控机理。

RWP-RK is a new type of transcription factor gene, which is involved in the development of plant embryo and the process of nitrogen metabolism. However, the biological function of these genes in maize, rice and other crops has not been reported. In our previous work, we found that OS1, encoding a transcription factor containing RWP-RK domains, involved in both the endosperm and embryo development. The nutrition constitution in the kernel was influenced in the os1 mutant. The expression analysis showed that OS1 gene was induced by low concentration of nitrogen and inhibited by high concentration of nitrogen. Genome-wide analysis indicated that the RWP-RK family has 15 members in the B73 reference genome. CRISPR/Cas9 technology was used to knock out the other members of the family. The zmrkd1 mutant and the os1 mutant are partly similar in seed. This project will futher study on the molecular function of OS1 and ZmRKD1, making the expression patern more clear in seeds of different periods and parts using RNA SEQ and in situ hybridization; Unerstand the molecular relations between the two genes by constructing double mutants; Identify the downstream regulated target genes of both OS1 and ZmRKD1 by means of Chip-seq and CRISPR / Cas9; Explain the relationship between the two genes and nitrogen using the technique of in vitro culture of kernel. Regulatory mechanism of the two genes in maize kernel development will be elucidated by comprehensive target gene information, expression data and phenotypic analysis.