水稻株型作为诸多农艺性状的综合体，是影响水稻产量高低的决定性因素。在水稻的驯化和育种改良过程中，合理的株型是人们选择的一个主要目标。为了鉴定控制株型的新基因，申请者所在实验室前期利用EMS诱变PAY1，筛选到一个株高降低、分蘖增多、穗长变短、穗粒数减少、粒长变短的突变体pay2。通过图位克隆定位到候选基因，遗传转化进一步确定该候选基因即为PAY2。PAY2可能编码一个含有U-box和ARM结构域的E3泛素连接酶。本研究将在此基础上，确定PAY1与PAY2的遗传互作关系，寻找PAY2的调控水稻株型的下游基因，解析其调控的分子机制及遗传网络。该研究结果不仅有助于加深我们对水稻株型调控分子机理及遗传网络的认识，而且为水稻的高产育种提供新的基因资源。

As an ensemble of important agronomic traits, plant architecture has a definitive effect on rice yield. During the process of rice domestication and genetic improvement, the selection of proper plant architecture is one of the main goals. To identify novel components that may regulate plant architecture, we isolated a mutant pay2 with reduced plant height, increased tillers, shortened panicle length, reduced grain number per panicle and shortened grain length, through screening the ethyl methanesulfonate (EMS)-mutagenzied PAY1 progeny. Gene PAY2 was identified by map-based cloning, and its function was further verified by genetic transformation. Sequence analysis showed that PAY2 may encode an E3 ubiquitin ligase with a U-box and an ARM domain. On this basis, this study is aiming at revealing the genetic relationships between PAY1 and PAY2 in regulating plant architecture, and looking for the downstream targets of PAY2 to uncover the molecular mechanism and construct the genetic regulation network. Results of this study will not only help to deepen our understanding of the molecular mechanism and genetic network underlying the regulation of plant architecture, but also provide new genetic resources for rice high-yield breeding.