Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis.
Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis.
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ATHKT1的天然变体可增强拟南芥两种野生种群的Na+积累。
DOI：
10.1371/journal.pgen.0020210
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发表时间：
2006-12-01
期刊：
影响因子：
4.5
通讯作者：
Salt, David E.
中科院分区：
文献类型：
--
作者：
Rus, Ana;Baxter, Ivan;Muthukumar, Balasubramaniam;Gustin, Jeff;Lahner, Brett;Yakubova, Elena;Salt, David E.
植物是固着的，因此已经形成了适应环境的机制，包括土壤中的矿物质营养成分。Ionomics是一种正在开发的功能基因组策略，旨在快速确定参与调控植物如何从土壤中获取和积累这些矿质养分的基因和基因网络。在这里，我们报道了高通量的来自不同拟南芥种质的地上部组织的元素图谱与基于DNA微阵列的批量分离分析和反向遗传学的结合，以快速从拟南芥野生种群中鉴定参与调控植物从土壤中获取和积累Na+的基因。对12个不同拟南芥地上部组织的元素分析表明，来自西班牙Tossa del Mar和日本Tsu的两个沿海拟南芥群体(TS-1和Tsu-1)积累的Na+水平高于Do Col-0和其他材料。我们发现编码Na+转运蛋白的AtHKT1是在ts-1和Tsu-1中导致地上部Na+升高的原因基因。此外，我们证实在AtHKT1上游约5kb的串联重复序列中的缺失是这些材料中观察到的AtHKT1根表达减少的原因。相互嫁接实验证明，根中AtHKT1表达的这种缺失是导致地上部Na+升高的原因。有趣的是，与hkt1-1缺失突变体不同的是，在盐胁迫条件下，这个新的AtHKT1等位基因不仅不具有盐敏感性，而且还具有更高的耐盐性。我们还在一个新的开放访问离子数据库--普渡离子信息管理系统(PIIMS；http://www.purdue.edu/dp/ionomics).)中提供了我们所有的元素特征数据利用基于DNA微阵列的基因分型方法，我们可以快速地确定AtHKT1是驱动我们在ts-1和Tsu-1中观察到的地上部Na+积累自然变异的随意基因。这种方法克服了在大多数拟南芥材料中缺乏已建立的遗传标记所造成的限制，并为鉴定基因功能开辟了一个巨大且易于处理的自然变异来源，不仅在离子学中，而且在许多其他生物过程中也是如此。与大多数动物不同，植物是固着的，萌发后不能离开质量较差的环境。因此，他们需要容忍他们遇到的特殊条件才能生存。这使得植物成为研究适应性变异的理想系统，尤其是拟南芥(Arabitopsis Thaliana)，它表现出大量的自然变异，并且存在许多遗传工具。利用分析化学、遗传学和基因组学相结合的方法，作者能够确定在西班牙和日本沿海地区(分别为Tossa del Mar和Tsu)的拟南芥种群中观察到的导致地上部钠(Na+)积累能力自然变异的特定遗传变化。他们观察到，负责调节HKT1表达的DNA缺失导致ATHKT1在西班牙和日本种群的根中表达减少。HKT1是一种已知的Na+转运体编码基因。这种表达的改变导致了在这两个种群中观察到的地上部Na+的升高。有趣的是，这个新版本的HKT1基因也与他们在日本人群中观察到的增强的耐盐性有关。
Plants are sessile and therefore have developed mechanisms to adapt to their environment, including the soil mineral nutrient composition. Ionomics is a developing functional genomic strategy designed to rapidly identify the genes and gene networks involved in regulating how plants acquire and accumulate these mineral nutrients from the soil. Here, we report on the coupling of high-throughput elemental profiling of shoot tissue from various Arabidopsis accessions with DNA microarray-based bulk segregant analysis and reverse genetics, for the rapid identification of genes from wild populations of Arabidopsis that are involved in regulating how plants acquire and accumulate Na+ from the soil. Elemental profiling of shoot tissue from 12 different Arabidopsis accessions revealed that two coastal populations of Arabidopsis collected from Tossa del Mar, Spain, and Tsu, Japan (Ts-1 and Tsu-1, respectively), accumulate higher shoot levels of Na+ than do Col-0 and other accessions. We identify AtHKT1, known to encode a Na+ transporter, as being the causal locus driving elevated shoot Na+ in both Ts-1 and Tsu-1. Furthermore, we establish that a deletion in a tandem repeat sequence approximately 5 kb upstream of AtHKT1 is responsible for the reduced root expression of AtHKT1 observed in these accessions. Reciprocal grafting experiments establish that this loss of AtHKT1 expression in roots is responsible for elevated shoot Na+. Interestingly, and in contrast to the hkt1–1 null mutant, under NaCl stress conditions, this novel AtHKT1 allele not only does not confer NaCl sensitivity but also cosegregates with elevated NaCl tolerance. We also present all our elemental profiling data in a new open access ionomics database, the Purdue Ionomics Information Management System (PiiMS; http://www.purdue.edu/dp/ionomics). Using DNA microarray-based genotyping has allowed us to rapidly identify AtHKT1 as the casual locus driving the natural variation in shoot Na+ accumulation we observed in Ts-1 and Tsu-1. Such an approach overcomes the limitations imposed by a lack of established genetic markers in most Arabidopsis accessions and opens up a vast and tractable source of natural variation for the identification of gene function not only in ionomics but also in many other biological processes. Unlike most animals, plants are sessile and cannot leave a poor-quality environment after germinating. They therefore need to tolerate the particular conditions they encounter to survive. This makes plants an ideal system for the study of adaptive variation, and this is particularly true of Arabidopsis thaliana (Arabidopsis), which shows substantial natural variation and for which numerous genetic tools exist. Using a combination of analytical chemistry, genetics, and genomics, the authors were able to identify the specific genetic alteration that drive the natural variation in shoot sodium (Na+) accumulation capacity observed in Arabidopsis populations from coastal regions of Spain and Japan (Tossa del Mar and Tsu, respectively). They observed that a deletion in the DNA responsible for regulating the expression of HKT1, a gene known to encode for a Na+ transporter, causes reduced expression of AtHKT1 in roots of both the Spanish and Japanese populations. Such altered expression results in the elevated shoot Na+ observed in these two populations. Interestingly, this novel version of the HKT1 genes is also associated genetically with the enhanced NaCl resistance they observe in the Japanese population.
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DOI：
10.1073/pnas.082123799
发表时间：
2002-04-30
影响因子：
11.1
作者：
Mäser, P;Hosoo, Y;Uozumi, N
通讯作者：
Uozumi, N
DOI：
10.1073/pnas.0404780101
发表时间：
2004-10-26
影响因子：
11.1
作者：
Gong, JM;Waner, DA;Schroeder, JI
通讯作者：
Schroeder, JI
影响因子：
9.4
作者：
Payne, KA;Bowen, HC;Broadley, MR
通讯作者：
Broadley, MR
影响因子：
7.3
作者：
Vreugdenhil, D;Aarts, MGM;Ernst, WHO
通讯作者：
Ernst, WHO
影响因子：
56.9
作者：
Lu, C;Tej, SS;Green, PJ
通讯作者：
Green, PJ