水稻磷转运蛋白OsPHT2;1在提高磷素利用率方面的作用

Function of Phosphate Transporter OsPHT2; 1 in Improving Phosphate Utilization in Rice

植物对磷的吸收与体内再分配需要多种磷酸盐转运系统共同作用。应用公开的植物基因组数据库和生物信息学分析确定了一个水稻低亲和磷酸盐转运蛋白基因OsPHT2；1。经半定量RT—PCR技术分析发现，OsPHT2；1在叶片强烈表达，在根系中微弱表达。OsPHT2；1在叶片中的表达量受光照调控并受低磷诱导。利用农杆菌介导Ubiquitin启动子过量表达OsPHT2；1，研究该基因在水稻中的生理功能。结果表明，水培试验中，正常供磷条件下OsPHT2；1-Oe植株叶部可溶性磷含量较野生型提高40．9％～48．5％，根部可溶性磷含量提高35．6％～51．2％，生物量提高25．1％～30．3％。缺磷条件下OsPHT2；1Oe植株叶部可溶性磷含量较野生型提高53．1％～70．3％，根部可溶性磷含量没有显著改变，生物量提高25．6％～28．5％。大田试验中，OsPH7＂2；1-Oe植株的上3叶和穗柄的全磷含量较野生型显著提高。表明0sPHT2；1可能参与磷素在叶部的积累以及植株体内磷的再分配过程。

The uptake and distribution of Pi in plants requires multiple Pi transport systems throughout growth and development. A putative low-affinity phosphate transporter gene, OsPHT2; 1, was identified based on the rice genomic databases and bioinformatics analysis. The expression pattern of OsPHT2 ; 1 in rice was investigated and the results showed its mRNA expressed in leaf mainly and in root little with the using of RT-PCR. In addition, OsPHT2 ; 1 induced by phosphate deficiency and light. By Agrobacteriurn tumefaciens transformation with an Ubiquitin （Ubi） promoter, the function of OsPHT2; 1 was tested by over-expression in rice. Compared with wild type, the Pi concentrations of OsPHT2 ; 1 -Oe plants increased by 40.9% -- 48.5 % in leaves, 35.6 % -- 51.2 % in roots and the biomass increased by 25.1%- 30.3 % at Pi-sufficient levels. The Pi concentrations in OsPHT2;1-Oe plants increased by 53. 1%- 70.3% in leaves and the biomass increased by 25.6%- 28.5%at Pi-deficient levels, while the Pi concentrations had no difference in roots. In field test, the total P concentrations of OsPHT2 ; I Oe plants significantly increased in the top three leaves and panicle axis. It indicated that OsPHT2;1 might be involved in the Pi accumulation in leaves and Pi translocation in plants.