Nicotianamine over-accumulation confers resistance to nickel in Arabidopsis thaliana
Nicotianamine over-accumulation confers resistance to nickel in Arabidopsis thaliana
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DOI：
10.1007/s11248-005-7159-3
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发表时间：
2005-10-01
影响因子：
3
通讯作者：
Czernic, P
中科院分区：
文献类型：
--
作者：
Pianelli, K;Mari, S;Czernic, P
烟酰胺是一种参与铁稳态的甲硫氨酸衍生物，能够在体外结合各种其他金属。为了研究其在体内的作用，我们表达了烟草胺合酶cDNA（TcNAS1）分离的多金属超富集植物Thlaspi caerulescens在拟南芥。表达TcNAS1的转基因植物过度积累NA，比野生型植物多100倍。此外，在不同的转基因株系中增加NA水平与增加的镍耐受性定量相关。在原生质体实验中，对镍的耐受性在细胞水平上表达，并且与NA含量增加有关。我们还发现，NA积累最多的系表现出高的耐镍性，并在镍污染的土壤上生长时，叶片中的镍积累显着。我们的研究结果突出了一个新的潜在作用，烟酰胺在重金属耐受性的细胞，但也在整个植物水平，很容易转座到一个非宽容的非超富集植物物种。这些结果为植物中烟酰胺含量的调节开辟了新的前景。
Nicotianamine is a methionine derivative involved in iron homeostasis, able to bind various other metals in vitro. To investigate its role in vivo, we expressed a nicotianamine synthase cDNA (TcNAS1) isolated from the polymetallic hyperaccumulator Thlaspi caerulescens in Arabidopsis thaliana. Transgenic plants expressing TcNAS1 over-accumulated NA, up to 100-fold more than wild type plants. Furthermore, increased NA levels in different transgenic lines were quantitatively correlated with increased nickel tolerance. The tolerance to nickel is expressed at the cellular level in protoplast experiments and is associated with an increased NA content. We have also shown that the most NA-over accumulating line showed a high tolerance to nickel and a significant Ni accumulation in the leaves when grown on nickel-contaminated soil. Our results highlight a new potential role for nicotianamine in heavy metal tolerance at the cellular but also at the whole plant level, easily transposable to a non-tolerant non-hyperaccumulator species. These results open new perspectives for the modulation of nicotianamine content in plants for phytoremediation.