AtIRT1, the Primary Iron Uptake Transporter in the Root, Mediates Excess Nickel Accumulation in Arabidopsis thaliana
AtIRT1, the Primary Iron Uptake Transporter in the Root, Mediates Excess Nickel Accumulation in Arabidopsis thaliana
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DOI：
10.1093/pcp/pcr089
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发表时间：
2011-08-01
影响因子：
4.9
通讯作者：
Mizuno, Takafumi
中科院分区：
文献类型：
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作者：
Nishida, Sho;Tsuzuki, Chisato;Mizuno, Takafumi
镍（Ni）是植物的必需营养素，但过量可能有毒。Ni在体内与铁（Fe）竞争，提高了植物通过Fe吸收系统竞争性吸收Ni的可能性。在这里，我们证明了AtIRT 1，在根中的主要Fe（2+）吸收转运蛋白，介导的镍积累在拟南芥。在水培培养中，过量镍暴露增加铁积累和AtIRT 1的相对转录水平在根中，表明过量镍诱导AtIRT 1在根中的表达。缺铁处理增加了植物对镍的积累，表明过量的镍通过铁吸收系统吸收，这是由铁饥饿引起的。此外，镍积累铁缺乏条件下显着低于AtIRT 1缺陷型突变体比野生型，Col-0。此外，AtIRT 1在酵母表达系统中显示出Ni（2+）吸收活性。这些数据表明，AtIRT 1运输Ni（2+）在根中，并强烈表明，镍的积累进一步加速AtIRT 1表示在响应过量的镍。
Nickel (Ni) is an essential nutrient for plants, but excessive amounts can be toxic. Ni competes with iron (Fe) in vivo, raising the possibility that Ni is competitively taken up via the Fe uptake system in plants. Here, we show evidence that AtIRT1, the primary Fe(2+) uptake transporter in the root, mediates Ni accumulation in Arabidopsis thaliana. In hydroponic cultures, excess Ni exposure increased Fe accumulation and the relative transcription level of AtIRT1 in roots, indicating that excess Ni induces AtIRT1 expression in roots. An Fe-deficient treatment increased Ni accumulation in plants, suggesting that excess Ni was absorbed via the Fe uptake system, which was induced by Fe starvation. Moreover, Ni accumulation under Fe-deficient conditions was markedly lower in AtIRT1-defective mutants than in the wild-type, Col-0. Furthermore, AtIRT1 showed Ni(2+) uptake activity in a yeast expression system. These data demonstrate that AtIRT1 transports Ni(2+) in roots, and strongly suggest that Ni accumulation is further accelerated by AtIRT1 that is expressed in response to excess Ni.