ABSTRACT Under salt stress, the regulatory mechanism of root water uptake in tomato species with different salt-tolerance remains unclear. Here, we compared water uptake, aquaporin expression and oxidative damage in roots of wild tomato Solanum pimpinellifolium ‘L03708ʹ and cultivated tomato Solanum lycopersicum ‘M82ʹ under salt stress (150 mM NaCl) and H2O2-caused oxidative stress which is usually induced by salt stress. The results showed that the seedling growth was inhibited and root hydraulic conductance in ‘M82ʹ was decreased under salt stress, whereas these were unchanged in ‘L03708ʹ. Under salt stress, the PIP1 aquaporin abundance was decreased in ‘M82ʹ but unchanged in ‘L03708ʹ, and the PIP2 abundance was decreased in both species. The membrane damage and hydrogen peroxide accumulation were more severe in ‘M82ʹ than ‘L03708ʹ under salt stress. Exogenous H2O2 increased the membrane electrolyte leakage and decreased the root hydraulic conductance, with the changes being more profound in ‘M82ʹ than ‘L03708ʹ. The PIP1 abundance was increased in ‘L03708ʹ but decreased in ‘M82ʹ by H2O2 treatment. These results suggest that the maintenance of PIP1 abundance and antioxidant defense capability in the wild tomato species may contribute to its maintenance of root water uptake and thus salt-tolerance under salt stress.

中文翻译：

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根系吸水的维持有助于盐胁迫下野生番茄物种的耐盐性

摘要 在盐胁迫下，不同耐盐性番茄品种根系吸水的调控机制尚不清楚。在这里，我们比较了盐胁迫（150 mM NaCl）和 H2O2 引起的氧化胁迫（通常由盐胁迫诱导）下野生番茄 Solanum pimpinellifolium 'L03708ʹ 和栽培番茄 Solanum lycopersicum 'M82ʹ 根的吸水、水通道蛋白表达和氧化损伤。结果表明，盐胁迫下'M82'的幼苗生长受到抑制，根系导水率降低，而'L03708'的根系水导率没有变化。在盐胁迫下，'M82ʹ'M82'中PIP1水通道蛋白丰度降低，'L03708'中PIP2丰度不变，两个物种的PIP2丰度均降低。在盐胁迫下，'M82'的膜损伤和过氧化氢积累比'L03708'更严重。外源性H2O2增加了膜电解质泄漏并降低了根部水力传导度，'M82'的变化比'L03708'更显着。通过 H2O2 处理，'L03708' 中的 PIP1 丰度增加，但'M82'中的 PIP1 丰度降低。这些结果表明，野生番茄物种中 PIP1 丰度和抗氧化防御能力的维持可能有助于维持根​​部吸水，从而维持盐胁迫下的耐盐性。