Mutation of the Arabidopsis NRT1.5 Nitrate Transporter Causes Defective Root-to-Shoot Nitrate Transport

被引：389

作者：

Lin, Shan-Hua ^{[1
]}

Kuo, Hui-Fen ^{[1
]}

Canivenc, Genevieve ^{[2
]}

Lin, Choun-Sea ^{[1
]}

Lepetit, Marc ^{[1
,2
]}

Hsu, Po-Kai

Tillard, Pascal ^{[2
]}

Lin, Huey-Ling ^{[3
]}

Wang, Ya-Yun ^{[1
]}

Tsai, Chyn-Bey ^{[1
]}

Gojon, Alain ^{[2
]}

Tsay, Yi-Fang ^{[1
]}

机构：

[1] Acad Sinica, Inst Mol Biol, Taipei 11529, Taiwan

[2] Univ Montpellier 2, UMR 5004, Agro M CNRS, INRA, F-34060 Montpellier 1, France

[3] Natl Chung Hsing Univ, Dept Hort, Taichung 40227, Taiwan

来源：

PLANT CELL | 2008年 / 20卷 / 09期

关键词：

D O I：

10.1105/tpc.108.060244

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Little is known about the molecular and regulatory mechanisms of long-distance nitrate transport in higher plants. NRT1.5 is one of the 53 Arabidopsis thaliana nitrate transporter NRT1 ( Peptide Transporter PTR) genes, of which two members, NRT1.1 (CHL1 for Chlorate resistant 1) and NRT1.2, have been shown to be involved in nitrate uptake. Functional analysis of cRNA-injected Xenopus laevis oocytes showed that NRT1.5 is a low-affinity, pH-dependent bidirectional nitrate transporter. Subcellular localization in plant protoplasts and in planta promoter-beta-glucuronidase analysis, as well as in situ hybridization, showed that NRT1.5 is located in the plasma membrane and is expressed in root pericycle cells close to the xylem. Knockdown or knockout mutations of NRT1.5 reduced the amount of nitrate transported from the root to the shoot, suggesting that NRT1.5 participates in root xylem loading of nitrate. However, root-to-shoot nitrate transport was not completely eliminated in the NRT1.5 knockout mutant, and reduction of NRT1.5 in the nrt1.1 background did not affect root-to-shoot nitrate transport. These data suggest that, in addition to that involving NRT1.5, another mechanism is responsible for xylem loading of nitrate. Further analyses of the nrt1.5 mutants revealed a regulatory loop between nitrate and potassium at the xylem transport step.

引用

页码：2514 / 2528

页数：15

共 60 条

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