Soil salinity is a major environmental constraint affecting agricultural production systems. Boron (B) is an essential micronutrient for plants. This work was aimed to reveal the mechanistic basis of amelioration of detrimental effects of salinity on plant performance by boron. Barley () plants were exposed to different boron (HBO, from 0 to 1 mM) and salt (NaCl, 0 and 100 mM) treatments demonstrating salt-tolerant phenotype in the presence of B. This was manifested by the significant increase in leaf and root fresh weight, enhanced CO assimilation, intercellular CO concentration, and stomatal conductance. A significant reduction in root and shoot Na content combined with higher amounts of K in the presence of B provided more optimal tissue K/Na ratios. At the cellular level, B-treated roots showed stronger stimulation of H-ATPase by NaCl (using net H flux as a proxy) and could maintain more negative membrane potential. This enhanced cytosolic potassium retention (by reducing GORK-mediated K loss) and provided a driving force for the operation of SOS1 Na/H exchanger explaining whole-plant ionomics data. Boron also affected the sensitivity of K- and Ca- permeable ion channels to reactive oxygen species. Significantly less root K loss but more root Ca uptake was observed for +B plants in response to HO, indicating the desensitization of K- permeable channels and the cell type-specific Ca- permeable transporters to HO, and the role of B in their regulation. Overall, B availability resulted in better salt tolerance in barley, which could be a suitable alternative to crop breeding aimed at enhancing salt tolerance.

中文翻译：

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了解硼对大麦盐度改善作用的机制基础（Hordeum vulgare）

土壤盐分是影响农业生产系统的主要环境制约因素。硼 (B) 是植物必需的微量营养素。这项工作的目的是揭示硼改善盐度对植物性能有害影响的机制基础。大麦 () 植物暴露于不同的硼（HBO，从 0 到 1 mM）和盐（NaCl，0 和 100 mM）处理，在 B 存在的情况下表现出耐盐表型。这表现为叶片和盐的显着增加。根鲜重、增强的二氧化碳同化、细胞间二氧化碳浓度和气孔导度。在 B 存在的情况下，根和茎的 Na 含量显着降低，同时 K 含量更高，从而提供了更优化的组织 K/Na 比。在细胞水平上，B 处理的根表现出 NaCl 对 H-ATP 酶的更强刺激（使用净 H 通量作为代表），并且可以维持更多的负膜电位。这增强了胞质钾保留（通过减少 GORK 介导的 K 损失），并为 SOS1 Na/H 交换器的运行提供了驱动力，解释了全植物离子组学数据。硼还影响钾离子通道和钙离子通道对活性氧的敏感性。对于 +B 植物，观察到响应 H2O 的根部 K 损失显着减少，但根部 Ca 吸收更多，表明 K 渗透通道和细胞类型特异性 Ca 渗透转运蛋白对 H2O 的脱敏，以及 B 在其调节中的作用。总体而言，硼的可用性导致大麦具有更好的耐盐性，这可能是旨在增强耐盐性的作物育种的合适替代方案。