The Salt Overly Sensitive (SOS) pathway regulates intracellular sodium ion homeostasis as a salt-stress response in plants. This pathway involves three main genes designated as SOS1, SOS2, and SOS3, which are members of the Na+ /H+ exchanger (NHX), CBL-interacting protein kinase (CIPK), and Calcineurin B-like (CBL) gene families, respectively. To identify and characterize SOS genes in spinach (Spinacia oleracea), a species of the Amaranthaceae family, we conducted genome-wide identification and phylogenetic analyses of NHX, CIPK, and CBL genes from four Amaranthaceae species, Arabidopsis, and rice. Most Amaranthaceae genes exhibited orthologous relationships with Arabidopsis and/or rice, except a clade of Vac-type Amaranthaceae NHX genes. Phylogenetic analyses also revealed gene gain/loss events in Amaranthaceae species and the intron-less to intron-rich evolution of CIPK genes. A bacterial protein-rooted CIPK tree allowed naming most of the phylogenetic clades based on their evolutionary history. Single S. oleracea (So) SOS1, SOS2, and SOS3 proteins were identified. Direct protein-protein interaction was observed between SoSOS2 and SoSOS3 but not between SoSOS2 and SoSOS1 based on yeast two-hybrid assay. This may suggest distinct modes of action of spinach SOS proteins compared to Arabidopsis SOS proteins. Unlike SoSOS1 and SoSOS2, which were expressed at similar or higher levels in leaves than roots, SoSOS3 expression was significantly higher in roots than leaves, suggesting its greater importance in roots. The expression of SoSOS3 was upregulated in both roots and leaves under salinity compared to the control; however, SoSOS1 was only upregulated in roots. Thus, this study demonstrated the conservation of SOS pathway genes in spinach and also highlighted the complexity of SOS signaling in Amaranthaceae species. This article is protected by copyright. All rights reserved.

中文翻译：

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菠菜盐过度敏感家族基因的分离与表征

盐过度敏感 (SOS) 途径调节细胞内钠离子稳态作为植物中的盐胁迫反应。该途径涉及称为 SOS1、SOS2 和 SOS3 的三个主要基因，它们分别是 Na+ /H+ 交换器 (NHX)、CBL 相互作用蛋白激酶 (CIPK) 和钙调神经磷酸酶 B 样 (CBL) 基因家族的成员。为了鉴定和表征苋科植物菠菜（Spinacia oleracea）中的 SOS 基因，我们对来自四种苋科植物、拟南芥和水稻的 NHX、CIPK 和 CBL 基因进行了全基因组鉴定和系统发育分析。除了 Vac 型苋科 NHX 基因的进化枝外，大多数苋科基因与拟南芥和/或水稻表现出直系同源关系。系统发育分析还揭示了苋科物种中的基因获得/损失事件以及 CIPK 基因从无内含子到富含内含子的进化。以细菌蛋白质为根的 CIPK 树允许根据它们的进化历史命名大多数系统发育进化枝。鉴定了单一的甘薯 (So) SOS1、SOS2 和 SOS3 蛋白。基于酵母双杂交试验，在 SoSOS2 和 SoSOS3 之间观察到直接的蛋白质 - 蛋白质相互作用，但在 SoSOS2 和 SoSOS1 之间没有观察到。这可能表明与拟南芥 SOS 蛋白相比，菠菜 SOS 蛋白具有不同的作用模式。与 SoSOS1 和 SoSOS2 在叶子中的表达水平相似或高于根不同，SoSOS3 在根中的表达显着高于叶子，这表明其在根中的重要性更高。与对照相比，盐度下SoSOS3在根和叶中的表达均上调；然而，SoSOS1 仅在根中上调。因此，这项研究证明了菠菜中 SOS 通路基因的保守性，并强调了苋科物种中 SOS 信号传导的复杂性。本文受版权保护。版权所有。