植物花的形成受花器官特征基因与其调节基因相互作用、共同决定。RBR是植物的一类小家族蛋白，主要通过与其它蛋白互作，参与调节细胞周期的进程，控制细胞的生长、分化与器官的发育等重要生物学过程。水稻有2个功能未知的RBR基因。我们从水稻中获得了2种表型相似、小穗发育明显异常但其它性状发育正常的花器官突变体。图位克隆表明，这两种突变体均由OsRBR1功能缺失引起。OsRBR1具有与动物RB及其它植物RBR相似的保守结构域。初步推测，作为调节水稻花器官形成的关键因子，OsRBR1可能通过与其它蛋白质互作，调节花器官特征基因及其下游基因的表达，从而控制水稻花器官的形成。在此基础上，本项目拟综合采用酵母双杂交、免疫共沉淀、表达谱测序等技术方法，进一步分析OsRBR1的功能和表达特征，阐明OsRBR1特异调节水稻小穗形成的作用机制。本研究的结果将为全面理解水稻小穗形成的分子调控机制提供新见解。

The floral formatin in plant is determined by the interactions between floral organ identity genes and their regulators. RBRs belong to a small gene family in plant, mainly participate in important biological processes, such as regulation cell cycle progression, control cell growth and differentiation and organ formation through interactions with other proteins. There are two unknown functional genes of RBR in rice. We obtained two kinds of floral organ mutants with similar phenotype in rice. The result of positional cloning showed that these two mutants were caused by loss-of-function mutantion of the same gene OsRBR1. OsRBR1 showes the conserved domains similar to that of animal RB and other plant RBRs. It is presumed that, as a critical factor in regulation of floral organ formation in rice, OsRBR1 probably regulates the expression of floral organ identity genes and their downstream genes through interactions with other proteins, so as to control floral organ formation in rice. On the basis of previous studies, this project aims to further analysis the function and expression pattern of OsRBR1 gene, and to clarify the specific regulation mechanism of OsRBR1 on spikelet development in rice, by comprehensive using of the technique and methods of yeast two hybrid, co-immunoprecipitation, expression profiling sequencing, and so on. The results of this study will provide some new insights into the comprehensive understanding the molecular regulation mechanism of spikelet formation in rice.