SummaryTetraspanins (TETs) are integral membrane proteins, characterized by four transmembrane domains and a unique signature motif in their large extracellular loop. They form dynamic supramolecular complexes called tetraspanin‐enriched microdomains (TEMs), through interactions with partner proteins. In plants, TETs are involved in development, reproduction and immune responses, but their role in defining abiotic stress responses is largely underexplored. We focused on OsTET5, which is differentially expressed under various abiotic stresses and localizes to both plasma membrane and endoplasmic reticulum. Using overexpression and underexpression transgenic lines we demonstrate that OsTET5 contributes to salinity and drought stress tolerance in rice. OsTET5 can interact with itself in yeast, suggesting homomer formation. Immunoblotting of native PAGE of microsomal fraction enriched from OsTET5‐Myc transgenic rice lines revealed multimeric complexes containing OsTET5, suggesting the potential formation of TEM complexes. Transcriptome analysis, coupled with quantitative PCR‐based validation, of OsTET5‐altered transgenic lines unveiled the differential expression patterns of several stress‐responsive genes, as well as those coding for transporters under salt stress. Notably, OsTET5 plays a crucial role in maintaining the ionic equilibrium during salinity stress, particularly by preserving an elevated potassium‐to‐sodium (K+/Na+) ratio. OsTET5 also regulates reactive oxygen species homeostasis, primarily by modulating the gene expression and activities of antioxidant pathway enzymes and proline accumulation. Our comprehensive investigation underscores the multifaceted role of OsTET5 in rice, accentuating its significance in developmental processes and abiotic stress tolerance. These findings open new avenues for potential strategies aimed at enhancing stress resilience and making valuable contributions to global food security.

中文翻译：

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四跨膜蛋白 5 通过调节水稻中的离子和活性氧稳态来协调盐胁迫的恢复能力


摘要四跨膜蛋白 (TET) 是完整的膜蛋白，其特征在于四个跨膜结构域和其大细胞外环中的独特特征基序。它们通过与伙伴蛋白相互作用形成动态超分子复合物，称为富含四跨膜蛋白的微域（TEM）。在植物中，TET 参与发育、繁殖和免疫反应，但它们在定义非生物胁迫反应中的作用在很大程度上尚未得到充分研究。我们关注 OsTET5，它在各种非生物胁迫下有差异表达，并且定位于质膜和内质网。使用过表达和表达不足的转基因株系，我们证明了 OsTET5 有助于水稻的盐度和干旱胁迫耐受性。 OsTET5 在酵母中可以与其自身相互作用，表明同聚体的形成。对 OsTET5-Myc 转基因水稻品系富集的微粒体部分进行天然 PAGE 免疫印迹显示含有 OsTET5 的多聚体复合物，表明可能形成 TEM 复合物。 OsTET5 改变的转基因品系的转录组分析结合基于定量 PCR 的验证，揭示了几种应激反应基因以及盐胁迫下编码转运蛋白的基因的差异表达模式。值得注意的是，OsTET5 在盐度胁迫期间维持离子平衡方面发挥着至关重要的作用，特别是通过保持较高的钾钠 (K+/Na+) 比率。 OsTET5 还主要通过调节抗氧化途径酶的基因表达和活性以及脯氨酸积累来调节活性氧稳态。 我们的全面研究强调了 OsTET5 在水稻中的多方面作用，强调了其在发育过程和非生物胁迫耐受性中的重要性。这些发现为旨在增强抗压能力并为全球粮食安全做出宝贵贡献的潜在战略开辟了新途径。