In response to our ever‐increasing demand for metals, phytotechnologies are being developed to limit the environmental impact of conventional metal mining. However, the development of these technologies, which rely on plant species able to tolerate and accumulate metals, is partly limited by our lack of knowledge of the underlying molecular mechanisms. In this work, we aimed to better understand the role of metal transporters of the IRON REGULATED 1/FERROPORTIN (IREG/FPN) family from the nickel hyperaccumulator Leucocroton havanensis from the Euphorbiaceae family. Using transcriptomic data, we identified two homologous genes, LhavIREG1 and LhavIREG2, encoding divalent metal transporters of the IREG/FPN family. Both genes are expressed at similar levels in shoots, but LhavIREG1 shows higher expression in roots. The heterologous expression of these transporters in A. thaliana revealed that LhavIREG1 is localized to the plasma membrane, whereas LhavIREG2 is located on the vacuole. In addition, the expression of each gene induced a significant increase in nickel tolerance. Taken together, our data suggest that LhavIREG2 is involved in nickel sequestration in vacuoles of leaf cells, whereas LhavIREG1 is mainly involved in nickel translocation from roots to shoots, but could also be involved in metal sequestration in cell walls. Our results suggest that paralogous IREG/FPN transporters may play complementary roles in nickel hyperaccumulation in plants.

中文翻译：

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镍超富集植物 Leucocroton havanensis 的 IREG/Ferroportin 转运蛋白的不同作用

为了满足我们对金属不断增长的需求，人们正在开发植物技术来限制传统金属开采对环境的影响。然而，这些技术的发展依赖于能够耐受和积累金属的植物物种，部分由于我们缺乏对潜在分子机制的了解而受到限制。在这项工作中，我们的目的是更好地了解镍超富集器中铁调节 1/铁转运蛋白 (IREG/FPN) 家族金属转运蛋白的作用哈瓦那白巴豆来自大戟科。利用转录组数据，我们鉴定了两个同源基因，拉夫IREG1和拉夫IREG2，编码 IREG/FPN 家族的二价金属转运蛋白。两种基因在芽中的表达水平相似，但是拉夫IREG1在根中表达较高。这些转运蛋白在拟南芥中的异源表达表明，LhavIREG1 位于质膜上，而 LhavIREG2 位于液泡上。此外，每个基因的表达都会诱导镍耐受性显着增加。综上所述，我们的数据表明，LhavIREG2 参与叶细胞液泡中的镍螯合，而 LhavIREG1 主要参与镍从根到芽的易位，但也可能参与细胞壁中的金属螯合。我们的结果表明旁系同源 IREG/FPN 转运蛋白可能在植物镍超积累中发挥补充作用。