Identification and characterization of the Arabidopsis PHO1 gene involved in phosphate loading to the xylem
Identification and characterization of the Arabidopsis PHO1 gene involved in phosphate loading to the xylem
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DOI：
10.1105/tpc.000745
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发表时间：
2002-04-01
期刊：
影响因子：
11.6
通讯作者：
Poirier, Y
中科院分区：
文献类型：
--
作者：
Hamburger, D;Rezzonico, E;Poirier, Y
拟南芥突变体pho 1缺乏从根表皮和皮层细胞到木质部的Pi转移。PHO 1基因通过图位克隆的方法进行鉴定。PHO 1的N-末端一半主要是亲水性的，而C-末端一半具有六个潜在的跨膜结构域。PHO 1显示没有同源性与任何特征的溶质转运蛋白，包括家庭的H+-Pi cotransporters中确定的植物和真菌。PHO 1与异嗜性小鼠白血病逆转录病毒的Rcm 1哺乳动物受体和参与交配信息素信号转导途径的酿酒酵母Syg 1蛋白具有最高的同源性。PHO 1主要在根中表达，并且在Pi胁迫下微弱上调。PHO 1启动子-β-葡萄糖醛酸苷酶构建体的研究揭示了PHO 1启动子在根的中柱细胞和下胚轴的下部中的主要表达。原生木质部导管附近的皮层细胞也有β-葡萄糖醛酸酶染色。拟南芥基因组含有10个额外的基因显示与PHO 1同源。因此，PHO 1定义了一类新的蛋白质参与植物中的离子运输。
The Arabidopsis mutant pho1 is deficient in the transfer of Pi from root epidermal and cortical cells to the xylem. The PHO1 gene was identified by a map-based cloning strategy. The N-terminal half of PHO1 is mainly hydrophilic, whereas the C-terminal half has six potential membrane-spanning domains. PHO1 shows no homology with any characterized solute transporter, including the family of H+-Pi cotransporters identified in plants and fungi. PHO1 shows highest homology with the Rcm1 mammalian receptor for xenotropic murine leukemia retroviruses and with the Saccharomyces cerevisiae Syg1 protein involved in the mating pheromone signal transduction pathway. PHO1 is expressed predominantly in the roots and is upregulated weakly under Pi stress. Studies with PHO1 promoter-beta-glucuronidase constructs reveal predominant expression of the PHO1 promoter in the stelar cells of the root and the lower part of the hypocotyl. There also is beta-glucuronidase staining of enclodermal cells that are adjacent to the protoxylem vessels. The Arabidopsis genome contains 10 additional genes showing homology with PHO1. Thus, PHO1 defines a novel class of proteins involved in ion transport in plants.