Increased nicotianamine biosynthesis confers enhanced tolerance of high levels of metals, in particular nickel, to plants
Increased nicotianamine biosynthesis confers enhanced tolerance of high levels of metals, in particular nickel, to plants
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DOI：
10.1093/pcp/pci196
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发表时间：
2005-11-01
影响因子：
4.9
通讯作者：
Nishizawa, NK
中科院分区：
文献类型：
--
作者：
Kim, S;Takahashi, M;Nishizawa, NK
烟胺是一种源自植物的金属螯合剂，由烟胺合酶催化s -腺苷蛋氨酸三聚体化而产生。我们建立了转基因拟南芥和烟草植株，组成性地过表达大麦烟胺合成酶基因。烟草胺合成酶过表达导致转基因植物中烟草胺的生物合成增加，从而增强了植物对高水平金属，特别是镍的耐受性。过量镍胁迫下，拟南芥4个烟胺合成酶基因启动子活性均升高，表明烟胺在植物对镍的脱毒过程中起重要作用。此外，具有高水平烟胺的转基因烟草植株在富镍蛇纹石土壤中生长良好，没有出现任何镍毒性症状。我们的研究结果表明，烟胺在金属解毒中起着至关重要的作用，这可以成为植物修复中使用的有力工具。
Nicotianamine, a plant-derived chelator of metals, is produced by the trimerization of S-adenosylmethionine catalyzed by nicotianamine synthase. We established transgenic Arabidopsis and tobacco plants that constitutively overexpress the barley nicotianamine synthase gene. Nicotianamine synthase overexpression resulted in increased biosynthesis of nicotianamine in transgenic plants, which conferred enhanced tolerance of high levels of metals, particularly nickel, to plants. Promoter activities of four nicotianamine synthase genes in Arabidopsis were all increased in response to excess nickel, suggesting that nicotianamine plays an important role in the detoxification of nickel in plants. Furthermore, transgenic tobacco plants with a high level of nicotianamine grew well in a nickel-enriched serpentine soil without developing any symptoms of nickel toxicity. Our results indicate that nicotianamine plays a critical role in metal detoxification, and this can be a powerful tool for use in phytoremediation.