Plant NHX antiporters are critical for cellular pH, Na⁺, and K⁺ homeostasis and salt tolerance. Even though their genomic and functional studies have been conducted in many species, the grapevine NHX family has not been described yet. Our work highlights the presence of six VvNHX genes whose phylogenetic analysis revealed their classification in two distinct groups: group I vacuolar (VvNHX1–5) and group II endosomal (VvNHX6). Several cis-acting regulatory elements related to tissue-specific expression, transcription factor binding, abiotic/biotic stresses response, and light regulation elements were identified in their promoter. Expression profile analyses of VvNHX genes showed variable transcription within organs and tissues with diverse patterns according to biochemical, environmental, and biotic treatments. All VvNHXs are involved in berry growth, except VvNHX5 that seems to be rather implicated in seed maturation. VvNHX4 would be more involved in floral development, while VvNHX2 and 3 display redundant roles. QPCR expression analyses of VvNHX1 showed its induction by NaCl and KNO₃ treatments, whereas VvNHX6 was induced by ABA application and strongly repressed by PEG treatment. VvNHX1 plays a crucial role in a bunch of grape developmental steps and adaptation responses through mechanisms of phyto-hormonal signaling. Overall, VvNHX family members could be valuable candidate genes for grapevine improvement.

中文翻译：

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葡萄NHX反转运蛋白的全基因组鉴定，分子表征和基因表达分析表明，它们参与生长，成熟，种子休眠和胁迫反应。

植物NHX反转运蛋白对于细胞的pH值，Na ⁺和K ⁺稳态和盐耐受性至关重要。尽管已经在许多物种中进行了基因组和功能研究，但尚未描述葡萄树NHX家族。我们的工作突出了六个VvNHX基因的存在，它们的系统发育分析揭示了它们在两个不同的组中的分类：I型液泡（VvNHX1-5）和II型内体液（VvNHX6）。在其启动子中鉴定了几种与组织特异性表达，转录因子结合，非生物/生物应激反应以及光调节元件有关的顺式调节元件。VvNHX的表达谱分析根据生化，环境和生物治疗，这些基因在器官和组织内显示出可变的转录，并具有多种模式。除了似乎与种子成熟有关的VvNHX5，所有VvNHX都参与了浆果的生长。VvNHX4将更多地参与花卉发育，而VvNHX2和3显示出多余的作用。对VvNHX1的QPCR表达分析表明，其被NaCl和KNO ₃处理诱导，而VvNHX6被ABA诱导并被PEG处理强烈抑制。VvNHX1在一系列葡萄发育步骤和通过植物激素信号传导机制的适应性反应中起着至关重要的作用。总体而言，VvNHX 家庭成员可能是葡萄改良的有价值的候选基因。