A newly isolated Na+/H+ antiporter gene, DmNHX1, confers salt tolerance when expressed transiently in Nicotiana benthamiana or stably in Arabidopsis thaliana
A newly isolated Na+/H+ antiporter gene, DmNHX1, confers salt tolerance when expressed transiently in Nicotiana benthamiana or stably in Arabidopsis thaliana
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DOI：
10.1007/s11240-012-0142-9
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发表时间：
2012-03
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影响因子：
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通讯作者：
Hui Zhang;Yaxin Liu;Yuan Xu;S. Chapman;A. Love;Tao Xia
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作者：
Hui Zhang;Yaxin Liu;Yuan Xu;S. Chapman;A. Love;Tao Xia
钠/氢转运体跨膜转运离子，因此在pH和电解质动态平衡中起着重要作用。为了进一步了解植物液泡Na+/H+转运蛋白的机制和功能，从菊花中分离到一种新的Na+/H+逆向转运蛋白DmNHX1，并对其进行了鉴定。DmNHX1全长1,897个碱基，开放阅读框为1,653个碱基。对突变的NHX基因在酿酒酵母中的功能互补研究表明，编码的蛋白DmNHX1具有广泛的阳离子特异性(Na+，K+，Li+)，并具有潮霉素B的耐受性。定量RT-PCR结果表明，DmNHX1基因在所有受试组织中均受到盐胁迫的诱导，尤其是在叶片中表达水平最高。农杆菌介导法瞬时表达DmNHX1基因提高了烟草叶片的耐盐性，表现为与对照相比，叶片的漂白减少和叶绿素含量增加。此外，过表达DmNHX1还提高了转基因拟南芥的耐盐性。我们的研究表明，DmNHX1在菊花的盐分运输中起着至关重要的作用，可能用于提高菊花的耐盐性。
Sodium/hydrogen transporters transfer ions across membranes and thus play an important role in pH and electrolyte homeostasis. To further understand the mechanism and function of the plant vacuolar Na+/H+, a new Na+/H+antiporter, namedDmNHX1, was isolated from chrysanthemum (Dendranthema morifolium) and characterized. The total length ofDmNHX1is 1,897 bp, with an open reading frame of 1,653 bp. Functional complementation studies inSaccharomyces cerevisiaestrains with mutated endogenousNHXgenes showed that the encoded protein, DmNHX1, has a broad cation specificity (Na+, K+, Li+) and confered hygromycin B tolerance. Quantitative RT-PCR revealed that the transcription level ofDmNHX1was induced by salt stress in all studied tissues, especially expressed highest in the leaves.Agrobacterium-mediated transient expression ofDmNHX1inNicotiana benthamianaenhanced the salt tolerance of leaf discs, as indicated by reduced bleaching and increased chlorophyll content when compared to that of controls. In addition, overexpressingDmNHX1resulted in enhanced salinity tolerance in transgenicArabidopsis thaliana. Our studies suggest thatDmNHX1plays the crucial role in salt transport of chrysanthemum and could be applied for the improvement of salt tolerance.