Elevated Expression of Vacuolar Nickel Transporter Gene IREG2 Is Associated With Reduced Root-to-Shoot Nickel Translocation in Noccaea japonica
Elevated Expression of Vacuolar Nickel Transporter Gene IREG2 Is Associated With Reduced Root-to-Shoot Nickel Translocation in Noccaea japonica
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DOI：
10.3389/fpls.2020.00610
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发表时间：
2020-06-03
影响因子：
5.6
通讯作者：
Furuta, Naoki
中科院分区：
文献类型：
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作者：
Nishida, Sho;Tanikawa, Ryoji;Furuta, Naoki
一些金属超富集植物，包括镍（Ni）hyperaccumulator，已被确定在属。在芽中积累镍的能力在本属的物种和生态型之间差异很大，但是，鲜为人知的是这种种内和种间变异的分子机制。在这里，在水培培养，我们比较了Ni积累模式之间的Nabeea japonica，这起源于富镍的蛇纹石土壤在山。夕张（日本北海道）和蓝眼苔属（Nabeea caerulescensecotype Ganges），它们起源于法国南部的锌/铅矿土壤。与非积累型拟南芥相比，两种拟南芥都表现出极高的耐镍性。但200 μ M Ni处理后，N. caerulescens表现为叶片失绿，而N.日本鬼子没有表现出任何应激症状。地上部Ni含量以N处理较高。在N.这种差异是由于N.天蓝色的比N.日本。已知液泡Ni转运蛋白IREG 2通过将Ni隔离在根液泡中来抑制Ni从根向芽的转运。IREG 2基因在N. japonica是N.青色的此外，IREG 2基因组拷贝数在N. japonicathan inN. Caerulescens中的IREG 2表达量，表明IREG 2的表达量在N.日本。异源表达N. japonica和N.蓝绿藻和A. thaliana证实两个IREG 2基因都编码功能性液泡镍转运蛋白。综合这些结果，我们推测，在氮胁迫下，IREG 2基因的增殖导致了镍的根向地上部的转运减少。日本的。
A number of metal hyperaccumulator plants, including nickel (Ni) hyperaccumulators, have been identified in the genusNoccaea. The ability to accumulate Ni in shoots varies widely among species and ecotypes in this genus; however, little is known about the molecular mechanisms underlying this intra- and inter-specific variation. Here, in hydroponic culture, we compared Ni accumulation patterns betweenNoccaea japonica, which originated in Ni-enriched serpentine soils in Mt. Yubari (Hokkaido, Japan), andNoccaea caerulescensecotype Ganges, which originated in zinc/lead-mine soils in Southern France. BothNoccaeaspecies showed extremely high Ni tolerance compared with that of the non-accumulatorArabidopsis thaliana. But, following treatment with 200 mu M Ni,N. caerulescensshowed leaf chlorosis, whereasN. japonicadid not show any stress symptoms. Shoot Ni concentration was higher inN. caerulescensthan inN. japonica; this difference was due to higher efficiency of root-to-shoot Ni translocation inN. caerulescensthanN. japonica. It is known that the vacuole Ni transporter IREG2 suppresses Ni translocation from roots to shoots by sequestering Ni in the root vacuoles. The expression level of theIREG2gene in the roots ofN. japonicawas 10-fold that in the roots ofN. caerulescens. Moreover, the copy number ofIREG2per genome was higher inN. japonicathan inN. caerulescens, suggesting thatIREG2expression is elevated by gene multiplication inN. japonica. The heterologous expression ofIREG2ofN. japonicaandN. caerulescensin yeast andA. thalianaconfirmed that bothIREG2genes encode functional vacuole Ni transporters. Taking these results together, we hypothesize that the elevation ofIREG2expression by gene multiplication causes the lower root-to-shoot Ni translocation inN. japonica.