AtHKT1 drives adaptation of Arabidopsis thaliana to salinity by reducing floral sodium content.
AtHKT1 drives adaptation of Arabidopsis thaliana to salinity by reducing floral sodium content.
复制标题
DOI：
10.1371/journal.pgen.1007086
复制
发表时间：
2017-10
期刊：
影响因子：
4.5
通讯作者：
Chao DY
中科院分区：
文献类型：
--
作者：
An D;Chen JG;Gao YQ;Li X;Chao ZF;Chen ZR;Li QQ;Han ML;Wang YL;Wang YF;Chao DY
拟南芥高亲和力钾转运蛋白1（AtHKT 1）限制了根向地上部的钠转运，被认为是拟南芥耐盐性的关键。thaliana.然而，具有AtHKT 1“弱等位基因”的天然种质，例如大津-1，主要分布在盐碱地区，并且更耐盐。这些发现挑战了AtHKT 1在盐耐受性中的作用，并对AtHKT 1参与A. thaliana.在这里，我们报告说，AtHKT 1确实驱动自然变异的耐盐性A。thaliana和沿海AtHKT 1，所谓的弱等位基因，实际上在盐胁迫下降低花的钠含量方面是超功能的。我们的数据表明，AtHKT 1积极有助于盐适应的线性方式。正向和反向遗传学分析表明，单个AtHKT 1位点是导致Col-0和大津-1之间盐度适应性变异的主要原因。相互嫁接实验表明，芽AtHKT 1决定大津-1的耐盐性，而根AtHKT 1主要驱动Col-0的耐盐性。此外，有证据表明，大津-1 AtHKT 1在茎中高度表达，并且与Col-0 AtHKT 1相比，在限制钠流向花方面更有效。这种有效的钠回收到生殖器官赋予大津-1与Col-0相比，在盐胁迫下更强的生育力，从而提高大津-1适应沿海环境。综上所述，我们的数据不仅证实了AtHKT 1在盐适应中的作用，而且为我们理解植物的耐盐机制提供了线索。确定驱动植物适应盐度的遗传变异对于理解自然选择和进化机制至关重要。在这项研究中，我们发现基因AtHKT 1驱动A. thaliana到盐度。我们的证据直接表明，AtHKT 1等位基因在沿海接入大津-1赋予A.盐适应性增强的拟南芥。我们进一步的实验表明，沿海加入的适应性增强归因于高AtHKT 1在茎中的表达，导致低钠水平的花。我们的工作不仅阐明了AtHKT 1在植物局部适应盐胁迫中的作用，而且加深了我们对植物耐盐机制的理解。
Arabidopsis thaliana high-affinity potassium transporter 1 (AtHKT1) limits the root-to-shoot sodium transportation and is believed to be essential for salt tolerance in A. thaliana. Nevertheless, natural accessions with ‘weak allele’ of AtHKT1, e.g. Tsu-1, are mainly distributed in saline areas and are more tolerant to salinity. These findings challenge the role of AtHKT1 in salt tolerance and call into question the involvement of AtHKT1 in salinity adaptation in A. thaliana. Here, we report that AtHKT1 indeed drives natural variation in the salt tolerance of A. thaliana and the coastal AtHKT1, so-called weak allele, is actually hyper-functional in reducing flowers sodium content upon salt stress. Our data showed that AtHKT1 positively contributes to saline adaptation in a linear manner. Forward and reverse genetics analysis established that the single AtHKT1 locus is responsible for the variation in the salinity adaptation between Col-0 and Tsu-1. Reciprocal grafting experiments revealed that shoot AtHKT1 determines the salt tolerance of Tsu-1, whereas root AtHKT1 primarily drives the salt tolerance of Col-0. Furthermore, evidence indicated that Tsu-1 AtHKT1 is highly expressed in stems and is more effective compared to Col-0 AtHKT1 at limiting sodium flow to the flowers. Such efficient retrieval of sodium to the reproductive organ endows Tsu-1 with stronger fertility compared to Col-0 upon salt stress, thus improving Tsu-1 adaptation to a coastal environment. To conclude, our data not only confirm the role of AtHKT1 in saline adaptation, but also sheds light on our understanding of the salt tolerance mechanisms in plants. Identifying the genetic variation driving plant adaptation to salinity is critical for understanding natural selection and evolutionary mechanisms. In this study, we have revealed that the gene AtHKT1 drives natural variation in the adaptation of A. thaliana to salinity. Our evidences directly show that the AtHKT1 allele in the coastal accession Tsu-1 endows A. thaliana with enhanced adaptability to salinity. Our further experiments have demonstrated that the enhanced adaptability of the coastal accession is attributed to high AtHKT1 expression in stems, leading to low sodium levels in flowers. Our work not only elucidates the role of AtHKT1 in local adaptation to salinity but also improves our understanding of salt tolerance mechanisms of plants.