Conservation of the salt overly sensitive pathway in rice
Conservation of the salt overly sensitive pathway in rice
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DOI：
10.1104/pp.106.092635
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发表时间：
2007-02-01
期刊：
影响因子：
7.4
通讯作者：
Quintero, Francisco J.
中科院分区：
文献类型：
--
作者：
Martinez-Atienza, Juliana;Jiang, Xingyu;Quintero, Francisco J.
水稻的耐盐性与其从地上部排除Na+和维持低细胞Na+/K+比的能力有关。我们已经确定了水稻质膜Na+/H+交换，遗传和生化标准的基础上，是拟南芥（拟南芥）盐过度敏感1（SOS 1）蛋白的功能同源物。水稻转运蛋白OsSOS 1在酵母细胞质膜囊泡中具有Na+/H+交换能力，并能降低细胞内Na+的净含量。拟南芥蛋白激酶复合物SOS 2/SOS 3能激活OsSOS 1的磷酸化，并在体内和体外刺激其活性。此外，OsSOS 1抑制拟南芥sos 1 -1突变体的盐敏感性。这些结果代表了第一个分子和生化表征的Na+流出蛋白从单子叶植物。还鉴定了拟南芥蛋白激酶SOS 2及其钙依赖性激活剂SOS 3的推定水稻同源物。OsCIPK 24和OsCBL 4在酵母细胞中协同激活OsSOS 1，并与拟南芥中的OsSOS 1和AtSOS 1相互交换，形成异源蛋白激酶模块，激活OsSOS 1和AtSOS 1，抑制拟南芥sos 2和sos 3突变体的盐敏感性。这些结果表明SOS耐盐途径在谷类中起作用，并且证明双子叶植物和单子叶植物的SOS蛋白之间具有高度的结构保守性。
The salt tolerance of rice (Oryza sativa) correlates with the ability to exclude Na+ from the shoot and to maintain a low cellular Na+/K+ ratio. We have identified a rice plasma membrane Na+/H+ exchanger that, on the basis of genetic and biochemical criteria, is the functional homolog of the Arabidopsis (Arabidopsis thaliana) salt overly sensitive 1 (SOS1) protein. The rice transporter, denoted by OsSOS1, demonstrated a capacity for Na+/H+ exchange in plasma membrane vesicles of yeast (Saccharomyces cerevisiae) cells and reduced their net cellular Na+ content. The Arabidopsis protein kinase complex SOS2/ SOS3, which positively controls the activity of AtSOS1, phosphorylated OsSOS1 and stimulated its activity in vivo and in vitro. Moreover, OsSOS1 suppressed the salt sensitivity of a sos1-1 mutant of Arabidopsis. These results represent the first molecular and biochemical characterization of a Na+ efflux protein from monocots. Putative rice homologs of the Arabidopsis protein kinase SOS2 and its Ca2+-dependent activator SOS3 were identified also. OsCIPK24 and OsCBL4 acted coordinately to activate OsSOS1 in yeast cells and they could be exchanged with their Arabidopsis counterpart to form heterologous protein kinase modules that activated both OsSOS1 and AtSOS1 and suppressed the salt sensitivity of sos2 and sos3 mutants of Arabidopsis. These results demonstrate that the SOS salt tolerance pathway operates in cereals and evidences a high degree of structural conservation among the SOS proteins from dicots and monocots.