Zygophyllum xanthoxylum, a succulent xerophyte, possesses excellent salt tolerance which is closely associated with vacuolar Na⁺ compartmentation via ZxNHX1. RNA interference (RNAi)-mediated ZxNHX1 silencing impaired the characteristics of Na⁺ accumulation and thus inhibited normal growth of Z. xanthoxylum. To explore the molecular mechanisms underlying the changed phenotype, here we compared the different expression of salt-responsive genes between ZxNHX1-RNAi line and wild type at transcriptome level. The result showed that vast genes were differently expressed in leaves or roots between ZxNHX1-RNAi line and wild type under control condition or salt treatment. Among them, 142 unigenes were differently expressed in both roots and leaves under 50 mM NaCl for 6 h and 24 h between ZxNHX1-RNAi line and WT. These differentially expressed genes (DEGs) were related to transmembrane transportation based on Gene Ontology (GO) annotations. In terms of ion transport, 49 DEGs were identified, in which some genes associated with Na⁺ and K⁺ homeostasis were down-regulated; meanwhile, silencing of ZxNHX1 triggered the differential expression of several genes involved in the transport of important nutrient elements including N, P, Ca, and Mg. Besides, silencing of ZxNHX1 affected the expression level of 18 and 26 genes related to photosynthesis and ROS scavenging, respectively. This study provided strong evidences to indicate the dominant role of ZxNHX1 in maintaining the characteristics of salt accumulation and regulating the salt tolerance of Z. xanthoxylum.

Zygophyllum xanthoxylum是一种多汁的旱生植物，具有优异的耐盐性，这与通过 ZxNHX1 的液泡 Na ⁺区室密切相关。RNA 干扰 (RNAi) 介导的ZxNHX1沉默损害了 Na ⁺积累的特征，从而抑制了黄花菜的正常生长。为了探索改变表型的分子机制，我们在转录组水平上比较了ZxNHX1 -RNAi 系和野生型之间盐响应基因的不同表达。结果表明，ZxNHX1基因在叶或根中的表达存在差异。-RNAi 系和野生型在对照条件或盐处理下。其中，在ZxNHX1 -RNAi 系和 WT之间，142 个 unigenes在 50 mM NaCl 下 6 小时和 24 小时在根和叶中均有不同表达。这些差异表达基因（DEGs）与基于基因本体论（GO）注释的跨膜转运有关。在离子转运方面，鉴定出49个DEGs，其中一些与Na ⁺和K ⁺稳态相关的基因下调；同时，ZxNHX1 的沉默触发了参与重要营养元素（包括 N、P、Ca 和 Mg）运输的几个基因的差异表达。此外，ZxNHX1 的沉默分别影响与光合作用和 ROS 清除相关的 18 和 26 个基因的表达水平。这项研究提供了强有力的证据，表示ZxNHX1在维持积盐的特点和调节的耐盐性的主导作用霸王。