Abstract Thyme (Thymus vulgaris L.) is an important wild aromatic plant of the Mediterranean region which also has wide-ranging therapeutic properties. Its growth and chemical properties can be modified by agricultural practices especially mineral nutrition and irrigation. An experiment was undertaken to determine the effectiveness of exogenous foliar application of potassium and calcium against the adverse effects of NaCl-induced stress on Thyme. Salt stress decreased growth and photosynthetic assimilation rate. Leaf spray with K+ or Ca2+ reduced salt-induced damage by maintaining K+/Na+ and Ca2+/Na+ ratios, resulting in photosynthesis improvement under salt conditions. Salt-affected plants had higher concentrations of hydrogen peroxide (H2O2) and malondialdehyde (MDA) in their shoot tissues indicating oxidative damage to their cell membranes; Increased K+ and Ca2+ supply reduced the accumulation of both. Salinity appears to have upregulated the activity of antioxidant defense enzymes superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase, glutathione reductase, peroxide guaiacol, Monodehydroascorbate reductase, as well as Dehydroascorbate reductase. The application of K+ and Ca2+ solutions onto the foliage of NaCl-affected plants further enhanced the activity of the antioxidant enzymes of the ascorbate glutathione cycle potentially allowing a better protection of the cell membranes from reactive oxygen species.

中文翻译：

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钾和钙通过激活抗氧化系统提高百里香的耐盐性

摘要 百里香（Thymus vulgaris L.）是地中海地区重要的野生芳香植物，具有广泛的治疗作用。它的生长和化学特性可以通过农业实践来改变，尤其是矿物质营养和灌溉。进行了一项实验，以确定外源性叶面喷施钾和钙对 NaCl 诱导的百里香胁迫的不利影响的有效性。盐胁迫降低了生长和光合同化率。用 K+ 或 Ca2+ 喷洒叶片，通过维持 K+/Na+ 和 Ca2+/Na+ 比率减少盐诱导的损害，从而在盐条件下提高光合作用。受盐影响的植物在其芽组织中具有较高浓度的过氧化氢 (H2O2) 和丙二醛 (MDA)，表明它们的细胞膜受到氧化损伤；增加 K+ 和 Ca2+ 供应减少了两者的积累。盐度似乎上调了抗氧化防御酶超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、抗坏血酸过氧化物酶、谷胱甘肽还原酶、过氧化物愈创木酚、单脱氢抗坏血酸还原酶以及脱氢抗坏血酸还原酶的活性。将 K+ 和 Ca2+ 溶液施用于受 NaCl 影响的植物的叶子上，进一步增强了抗坏血酸谷胱甘肽循环的抗氧化酶的活性，从而可能更好地保护细胞膜免受活性氧的侵害。单脱氢抗坏血酸还原酶，以及脱氢抗坏血酸还原酶。将 K+ 和 Ca2+ 溶液施用于受 NaCl 影响的植物的叶子上，进一步增强了抗坏血酸谷胱甘肽循环的抗氧化酶的活性，从而可能更好地保护细胞膜免受活性氧的侵害。单脱氢抗坏血酸还原酶，以及脱氢抗坏血酸还原酶。将 K+ 和 Ca2+ 溶液施用于受 NaCl 影响的植物的叶子上，进一步增强了抗坏血酸谷胱甘肽循环的抗氧化酶的活性，从而可能更好地保护细胞膜免受活性氧的侵害。