中文摘要：

磷是植物体生长发育所必需的大量营养元素之一,广泛参与植物体多种生命活动。土壤中磷的有效性很低,是农业生产中限制作物产量的重要因素。OsPHR3（LOC_Os02g04640）属于MYB-CC家族,与水稻中磷信号途径中心调控因子OsPHR2是同源基因,且具有部分功能重叠。本研究利用转基因技术获得OsPHR3基因的突变体和超表达材料,通过水培实验、~（32）Pi同位素实验以及桶培实验来研究该基因在吸收利用磷素过程中的作用。水培实验表明,与野生型相比,突变体磷含量无明显差异,基因超表达能够提高水稻体内磷含量。~（32）Pi同位素实验显示,与野生型相比,缺磷时突变体吸收速率降低,而该基因超表达能够促进磷素的吸收与转运。桶培实验表明,该基因超表达能够增加水稻有效分蘖数,提高种子中磷含量,该基因缺失使得穗长变短。OsPHR3基因可能调控促进磷的吸收与向地上部转运。该研究将为以后分子育种提供依据。

英文摘要：

Phosphorus,an essential macronutrient element for plant growth and development,is broadly participating in various plant life activities.However,low availability of soil phosphate is a major constraint for crop production in many agricultural systems.OsPHR3（LOC_Os02g04640）is a homolog of OsPHR2,the central regulator of Pi-signaling in rice.Both OsPHR2 and OsPHR3 belong to the MYB-CC family members and have functional redundancy in part.In this study,OsPHR3 knock-out and over-expression transgenic plants were obtained.The hydroponic culture,~（32）Pi isotopic and pot experiments were used to demonstrate the role of OsPHR3 in rice phosphate untilization.First,hydroponic experiments showed that over-expression of OsPHR3 increased the phosphorus content of the rice,although the knock-out lines had no significant difference with wild type plants.Second,~（32）Pi isotopic experiments revealed that overexpression of the gene promoted the absorption and distribution of phosphate,while the absorption rate in knock-out lines decreased in comparison with wild type plants under Pi-deficient condition.Third,pot experiments demonstrated that over-expression of OsPHR3 enhanced the effective tillers and phosphorus content in seed.However,the panicle length in knock-out lines is shorter than in wild type plants.In conclusion,OsPHR3 is a potential transcription factor for improving P efficiency in rice through molecular breeding.