The succulent xerophyte Zygophyllum xanthoxylum (Bunge) Engl. can absorb Na⁺ from the soil as an osmoticum in order to resist osmotic stress. The tonoplast Na⁺/H⁺ antiporter ZxNHX1 is essential for maintaining the salt-accumulation characteristics of Z. xanthoxylum by compartmentalizing Na⁺ into vacuoles. Previous results revealed that the silencing of ZxNHX1 greatly decreased Na⁺ accumulation in Z. xanthoxylum under 50 mM NaCl due to the weakened compartmentalisation; in addition, K⁺ concentration also significantly reduced in ZxNHX1-RNAi lines. Yet, whether the reduction of K⁺ concentration was directly triggered by the silencing of ZxNHX1 remains unclear. In this study, the growth parameters and expression levels of ZxSOS1, ZxHKT1;1, ZxAKT1 and ZxSKOR were measured in wild-type and ZxNHX1-RNAi lines under control or –0.5 MPa osmotic stress. The results showed that the silencing of ZxNHX1 inhibited the plant growth, decreased Na⁺ concentration in leaves, reduced the transcript abundance of ZxSOS1 and dramatically increased that of ZxHKT1;1 in roots of Z. xanthoxylum under osmotic stress; whereas tissue K⁺ concentrations and the expression level of ZxSKOR displayed no significant variations, and the expression of ZxAKT1 were significantly reduced in ZxNHX1-RNAi lines under osmotic stress, compared with the wild type. These results suggest that in Z. xanthoxylum, ZxNHX1 can maintain the normal growth by compartmentalizing Na⁺ into vacuoles, and regulate the spatial distribution of Na⁺ indirectly by affecting the expressions of ZxSOS1 and ZxHKT1;1. Moreover, the silencing of ZxNHX1 is not the main reason that led to the reduction of K⁺ concentration in ZxNHX1-RNAi lines under 50 mM NaCl, and ZxNHX1 might be indirectly involved in regulating K⁺ homeostasis.

肉质旱生植物黄花椒（Bunge）Engl。可以作为渗透菌从土壤中吸收Na ⁺，以抵抗渗透胁迫。液泡膜Na ⁺ / H ⁺反向转运蛋白ZxNHX1对于维持Z的盐分累积特性至关重要。通过将Na ⁺划分为液泡来形成黄花椒。先前的结果显示ZxNHX1的沉默大大降低了Z中的Na ⁺积累。由于间隔作用减弱，在50 mM NaCl下的黄原胶；此外，K ⁺浓度在ZxNHX1-RNAi系。然而，尚不清楚Z ⁺ NHX1的沉默是否直接触发了K ⁺浓度的降低。本研究研究了ZxSOS1，ZxHKT1的生长参数和表达水平。如图1所示，在对照或–0.5 MPa渗透胁迫下，在野生型和ZxNHX1 - RNAi细胞系中测量了ZxAKT1和ZxSKOR。结果表明，ZxNHX1的沉默抑制了植物的生长，降低了叶片中Na ^+的浓度，降低了ZxSOS1的转录丰度，并显着增加了ZxHKT1的转录;Z的根中为1。花椒渗透胁迫下; 与野生型相比，在渗透胁迫下，ZxNHX1-RNAi系中的组织K ⁺浓度和ZxSKOR的表达水平没有显着变化，并且ZxAKT1的表达显着降低。这些结果表明在Z中。花椒，ZxNHX1可以通过将Na ⁺分为液泡来维持正常生长，并且通过影响ZxSOS1和ZxHKT1的表达间接调节Na ⁺的空间分布;1。此外，ZxNHX1的沉默并不是导致在50 mM NaCl下ZxNHX1 -RNAi系中K ⁺浓度降低的主要原因，ZxNHX1可能间接参与调节K ⁺稳态。