We have analysed the salt tolerance of two endemic halophytes of the genus Limonium, with high conservation value. In the present study, seed germination and growth parameters as well as different biomarkers-photosynthetic pigments, mono and divalent ion contents-associated to salt stress were evaluated in response to high levels of NaCl. The study was completed with an untargeted metabolomics analysis of the primary compounds including carbohydrates, phosphoric and organic acids, and amino acids, identified by using a gas chromatography and mass spectrometry platform. Limonium albuferae proved to be more salt-tolerant than L. doufourii, both at the germination stage and during vegetative growth. The degradation of photosynthetic pigments and the increase of Na+/K+ ratio under salt stress were more accentuated in the less tolerant second species. The metabolomics analysis unravelled several differences between the two species. The higher salt tolerance of L. albuferae may rely on its specific accumulation of fructose and glucose under high salinity conditions, the first considered as a major osmolyte in this genus. In addition, L. albuferae showed steady levels of citric and malic acids, whereas the glutamate family pathway was strongly activated under stress in both species, leading to the accumulation of proline (Pro) and γ-aminobutyric acid (GABA).

中文翻译：

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西班牙两种特有补血草品种耐盐性的见解。


我们对补血草属两种特有盐生植物的耐盐性进行了分析，具有较高的保护价值。在本研究中，评估了种子发芽和生长参数以及与盐胁迫相关的不同生物标志物（光合色素、一价和二价离子含量）对高浓度 NaCl 的反应。该研究通过使用气相色谱和质谱平台鉴定的主要化合物（包括碳水化合物、磷酸和有机酸以及氨基酸）进行非靶向代谢组学分析而完成。事实证明，无论是在发芽阶段还是在营养生长过程中，补血草都比 L. doufourii 更耐盐。盐胁迫下光合色素的降解和Na+/K+比率的增加在耐受性较差的第二个物种中更为突出。代谢组学分析揭示了这两个物种之间的一些差异。 L. albuferae 较高的耐盐性可能依赖于其在高盐度条件下特异性积累果糖和葡萄糖，这首先被认为是该属的主要渗透剂。此外，L. albuferae 的柠檬酸和苹果酸水平稳定，而谷氨酸家族途径在这两个物种的应激下均被强烈激活，导致脯氨酸 (Pro) 和 γ-氨基丁酸 (GABA) 的积累。