Fathalli Nour, Rajhi Imene, Jouini Rim, Abid Ghassen, Mejri Samiha, Ghorbel Abdelwahed, Jansen Robert K, Ouertani Rim Nefissi
Laboratory of Plant Molecular Physiology, Center of Biotechnology of Borj Cedria, BP 901, 2050, Hammam-Lif, Tunisia.
Laboratory of Legumes and Sustainable Agrosystems, Center of Biotechnology of Borj Cedria, BP 901, 2050, Hammam-Lif, Tunisia.
Protoplasma. 2025 May 2. doi: 10.1007/s00709-025-02070-0.
Salt stress is one of the major threats affecting crop yield. We assessed the behaviour of three barley genotypes, Ardhaoui, Manel, and Testour under 200 mM NaCl with the aim of evaluating the physiological and molecular mechanisms involved in barley salinity tolerance. Results revealed that salinity stress significantly decreases plant growth and water-holding capacity, particularly in the salt-sensitive genotype Testour. Tissue ionic content assessment demonstrated significantly distinct salinity-induced responses. The salt-tolerant genotype Ardhaoui accumulated more K and less Na content in both leaves and roots compared with the two other genotypes, leading to an increased K/Na ratio. Furthermore, the genotype Ardhaoui exhibited a stronger selectivity transport capacity of K over Na from root to leaf compared to both Manel and Testour. This effect was due to enhanced K⁺ retention and Na⁺ exclusion, regulated by HvHKT expression. Indeed, higher HvHKT2;1 gene transcript abundance was detected in both leaves and roots of the Ardhaoui genotype, as well as an upregulation of HvHKT1;1 and HvHKT1, mainly in Ardhaoui roots. In view of the severe impact of salinity on plant development, these findings could be applied to the genetic improvement of plant salinity tolerance.
盐胁迫是影响作物产量的主要威胁之一。我们评估了三种大麦基因型（阿尔达维、马内尔和泰斯图尔）在200 mM NaCl条件下的表现，旨在评估大麦耐盐性所涉及的生理和分子机制。结果表明，盐胁迫显著降低了植物生长和持水能力，尤其是在盐敏感基因型泰斯图尔中。组织离子含量评估显示出盐诱导的显著不同反应。与其他两种基因型相比，耐盐基因型阿尔达维在叶片和根部积累了更多的钾和更少的钠含量，导致钾/钠比值增加。此外，与马内尔和泰斯图尔相比，基因型阿尔达维从根到叶表现出更强的钾对钠的选择性运输能力。这种效应是由于HvHKT表达调节的钾保留增强和钠排斥增加所致。事实上，在阿尔达维基因型的叶片和根部均检测到较高的HvHKT2;1基因转录丰度，以及HvHKT1;1和HvHKT1的上调，主要在阿尔达维根部。鉴于盐胁迫对植物发育的严重影响，这些发现可应用于植物耐盐性的遗传改良。
