SummarySalinity significantly inhibits plant growth and development. While the recretohalophyte Limonium bicolor can reduce its ion content by secreting salt, the metabolic pathways it employs to adapt to high salt stress remain unclear. This study aims to unravel this enigma through integrated transcriptomic and metabolomic analyses of L. bicolor under salt stress conditions. The results showed that compared to the control (S0), low salt treatment (S1) led to a significant increase in plant growth, photosynthesis efficiency and antioxidant enzyme activity but caused no significant changes in organic soluble substance and ROS contents. However, high salt treatments (S3 and S4) led to a significant decrease in plant growth, photosynthesis efficiency and antioxidant enzyme activity, accompanied by a significant increase in organic soluble substance and ROS contents. A significant increase in phenolic compounds, such as caffeoyl shikimic acid and coniferin, upon the treatments of S1, S3 and S4, and a decrease and increase in flavonoids upon the treatments of S1 and S3 were also observed, respectively. This study also demonstrated that the expression patterns of key genes responsible for the biosynthesis of these metabolites are consistent with the observed trends in their accumulation levels. These results suggest that under low salt stress conditions, the halophyte L. bicolor experiences minimal osmotic and oxidative stress. However, under high salt stress conditions, it suffers severe osmotic and oxidative stress, and the increase in organic soluble substances and flavonoids serves as a key response to these stresses and also represents a good strategy for the alleviation of them.

中文翻译：

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综合转录组学和代谢组学分析揭示了双色柠檬响应盐胁迫的关键途径


摘要盐度显著抑制植物生长和发育。虽然 recretohalophyte Limonium bicolor 可以通过分泌盐来降低其离子含量，但它为适应高盐胁迫而采用的代谢途径仍不清楚。本研究旨在通过对盐胁迫条件下的双色乳杆菌进行综合转录组学和代谢组学分析来解开这一谜团。结果表明，与对照 （S0） 相比，低盐处理 （S1） 导致植物生长、光合作用效率和抗氧化酶活性显著增加，但有机可溶性物质和 ROS 含量没有显著变化。然而，高盐处理 （S3 和 S4） 导致植物生长、光合作用效率和抗氧化酶活性显著降低，同时有机可溶性物质和 ROS 含量显著增加。在 S1 、 S3 和 S4 处理下，咖啡酰莽草酸和针叶素等酚类化合物含量显著增加，在 S1 和 S3 处理下，黄酮类化合物含量分别减少和增加。这项研究还表明，负责这些代谢物生物合成的关键基因的表达模式与其观察到的其积累水平的趋势一致。这些结果表明，在低盐胁迫条件下，盐生植物 L. bicolor 经历的渗透和氧化应激最小。然而，在高盐胁迫条件下，它遭受严重的渗透和氧化胁迫，有机可溶性物质和类黄酮的增加是对这些胁迫的关键反应，也是缓解这些胁迫的良好策略。