The plasma membrane Na+/H+ antiporter SOS1 is essential for salt tolerance in tomato and affects the partitioning of Na+ between plant organs
The plasma membrane Na+/H+ antiporter SOS1 is essential for salt tolerance in tomato and affects the partitioning of Na+ between plant organs
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DOI：
10.1111/j.1365-3040.2009.01971.x
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发表时间：
2009-07-01
影响因子：
7.3
通讯作者：
Belver, Andres
中科院分区：
文献类型：
--
作者：
Olias, Raquel;Eljakaoui, Zakia;Belver, Andres
我们从番茄（Solanum lycopersicum）中鉴定了一个质膜Na+/H+反转运基因SlSOS1，并在酵母中异种表达证实了SlSOS1是AtSOS1的功能同源物。利用转录后基因沉默技术，研究了SlSOS1基因在番茄长距离Na+转运和耐盐性中的作用。选用番茄是因为其解剖结构比拟南芥复杂，而且具有重要的农业意义。SlSOS1基因表达降低的转基因番茄植株在盐水条件下的生长速度比野生型（WT）植株低。这种敏感性与盐胁迫下沉默植株叶片和根中Na+积累量较高，茎中Na+含量较低有关。抑制植株木质部汁液中Na+的分布存在差异，净Na+通量较低。此外，沉默植株根部的K+浓度低于野生植株。我们的研究结果表明，SlSOS1反转运蛋白不仅在盐度条件下维持离子稳态至关重要，而且对Na+在植物器官之间的分配也至关重要。番茄植株将Na+保留在茎部，从而阻止Na+到达光合组织的能力很大程度上取决于SlSOS1的功能。
We have identified a plasma membrane Na+/H+ antiporter gene from tomato (Solanum lycopersicum), SlSOS1, and used heterologous expression in yeast to confirm that SlSOS1 was the functional homolog of AtSOS1. Using post-transcriptional gene silencing, we evaluated the role played by SlSOS1 in long-distance Na+ transport and salt tolerance of tomato. Tomato was used because of its anatomical structure, more complex than that of Arabidopsis, and its agricultural significance. Transgenic tomato plants with reduced expression of SlSOS1 exhibited reduced growth rate compared to wild-type (WT) plants in saline conditions. This sensitivity correlated with higher accumulation of Na+ in leaves and roots, but lower contents in stems of silenced plants under salt stress. Differential distribution of Na+ and lower net Na+ flux were observed in the xylem sap in the suppressed plants. In addition, K+ concentration was lower in roots of silenced plants than in WT. Our results demonstrate that SlSOS1 antiporter is not only essential in maintaining ion homeostasis under salinity, but also critical for the partitioning of Na+ between plant organs. The ability of tomato plants to retain Na+ in the stems, thus preventing Na+ from reaching the photosynthetic tissues, is largely dependent on the function of SlSOS1.