Abstract Oryza sativa vacuolar H+-pyrophosphatase 1 (OVP1) regulates plant development and osmotic stress response through its function as an electrogenic proton (H+) pump in the vacuolar membrane. Here, we show that OVP1-overexpressing transgenic (OTG) rice plants display greater resistance to salt stress and root growth than wild-type (WT) rice plants. This improved performance of OTG plants under salt stress was attributed to increases in vacuolar pyrophosphatase (V-PPase) activity, ion uptake, and vacuolar cation ion antiporter gene expression. OTG plants had higher sodium levels in the vacuole than in the cytosol. Under natural paddy field conditions, OTG plants outperformed WT plants and produced more extensive root systems. OTG plants also had higher tiller number, V-PPase activity, chlorophyll content, membrane stability, and ion uptake than WT plants. Transcript profiling analyses revealed that the expression levels of vacuolar H+-pump genes (ATPase and OVP1) and ion antiporter genes (CAX, MHX, and NHX) were higher in OTG plants than in WT plants. These combined results suggest that OVP1 overexpression affects salt stress responses, root development, and biomass yield by regulating ion balance in rice.

中文翻译：

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质子泵基因 OVP1 的过表达通过调节水稻 (Oryza sativa L.) 中的离子平衡来增强盐胁迫耐受性、根系生长和生物量产量

摘要 水稻液泡 H+-焦磷酸酶 1 (OVP1) 通过其作为液泡膜中的生电质子 (H+) 泵的功能调节植物发育和渗透胁迫响应。在这里，我们显示过表达 OVP1 的转基因 (OTG) 水稻植物比野生型 (WT) 水稻植物对盐胁迫和根生长表现出更大的抵抗力。OTG 植物在盐胁迫下性能的改善归因于液泡焦磷酸酶 (V-PPase) 活性、离子吸收和液泡阳离子反向转运蛋白基因表达的增加。OTG 植物液泡中的钠含量高于细胞质中的钠含量。在天然稻田条件下，OTG 植物优于 WT 植物，并产生更广泛的根系。OTG 植物还具有较高的分蘖数、V-PPase 活性、叶绿素含量、膜稳定性、和离子吸收比 WT 植物。转录谱分析表明，OTG 植物中液泡 H+泵基因（ATPase 和 OVP1）和离子反向转运基因（CAX、MHX 和 NHX）的表达水平高于 WT 植物。这些综合结果表明 OVP1 过表达通过调节水稻中的离子平衡影响盐胁迫反应、根发育和生物量产量。