磷是植物生长发育的重要限制因子。近年来研究表明，影响根系发育基因AtLPRs通过铁氧化反应参与植物根尖对局部磷信号响应。申请人前期工作从水稻中筛选到了一个转录水平受缺磷诱导显著增加、编码蛋白具有铁氧化酶活性的基因，暂命名为OsLPR5。本申请将通过PCR和报告基因组织定位检测OsLPR5在水稻响应缺磷胁迫的时空表达模式；采用大肠杆菌、酵母、拟南芥等多种异源系统检测研究其编码蛋白的生理功能；利用OsLPR5突变体、超表达以及在此基础上创制的多种Marker基因启动子（如根尖细胞分裂分化和感受外部缺磷信号基因）+ 报告基因水稻转基因材料，从形态上、生理上以及分子水平上研究OsLPR5在水稻磷胁迫和磷信号分子响应过程中的功能与调控。本研究有望明确水稻中参与磷胁迫响应的编码铁氧化酶基因的生理功能，为揭示水稻缺磷信号转导途径的作用机理提供重要依据。

Phosphorus is an important limiting factor for plant growth and development. Recent studies show that AtLPRs affecting root growth is involved in plant root tip response to the local phosphate (Pi) signaling through iron oxidation reaction. In our previous study, a Pi-deficient responsive gene was identified in rice, designated as OsLPR5. Its encoding protein has ferroxidase activity. In the present study, the spacial and temporal expression pattern of OsLPR5 in response to Pi-deficiency in rice will be detected by PCR and reporter genes. We intend to study the physiological function of OsLPR5 by using heterologous system such as Escherichia coli, yeast, Arabidopsis. Morphological, physiological and molecular aspects of OsLPR5 mutants, over-expression plants and Marker gene promoters (such as genes for the differentiation of cell in root tip and the Pi-deficient response) + GUS/GFP transgenic rice will be characterized for the function of OsLPR5 under Pi-deficient stresses and Pi-response signaling molecules. This study is expected to expose physiological functions of OsLPR5 under phosphate starvation stresses in rice, and provide valuable evidences to reveal the mechanism of Pi-deficient signal transduction pathways in rice.