Arbuscular mycorrhizal fungi (AMF) and potassium humate (KH) are separately known as significant biostimulants, but their combined effect on plants remains elusive. This study investigated the single and combined roles of AMF and KH on the antioxidant defense system in Russian olive (Elaeagnus angustifolia L.) leaves. Soil below the seeds was inoculated with indigenous AMF spores (Funneliformis, Claroideoglomus; 500 spores per seed). The KH (1.5 g/ per 1 kg of seed) was applied during sowing. Growth, leaf-water ratio, chlorophyll fluorescence, lipid peroxidation, H2O2 content, antioxidant enzymes, and antioxidant capacity were analyzed in treated and untreated plants. Combined AMF and KH applications had a greater recovery effect on vegetative organ growth than separate treatments. With combined treatment, plants maintained leaf water status and chlorophyll fluorescence, while peroxidation of lipid membranes and H2O2 content was reduced. Moreover, increases in superoxide dismutase and glutathione reductase activity prevented cellular damage from reactive oxygen species. Total phenolic content and antioxidant capacity values were remarkably higher in plants grown under the combined treatment. As a result, compared with their separate applications, a combination of AMF and KH enhanced the antioxidant defense system by increasing antioxidant enzymes and antioxidant capacity and, thus, could be used to enhance plant growth.

中文翻译：

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丛枝菌根真菌和腐植酸钾作为生物刺激剂的组合：沙棘抗氧化防御系统和自由基清除能力的变化

丛枝菌根真菌 (AMF) 和腐植酸钾 (KH) 分别被称为重要的生物刺激剂，但它们对植物的综合影响仍然难以捉摸。本研究调查了 AMF 和 KH 对俄罗斯橄榄 (Elaeagnus angustifolia L.) 叶子的抗氧化防御系统的单一和组合作用。种子下方的土壤用本地 AMF 孢子（Funneliformis、Claroideoglomus；每粒种子 500 个孢子）接种。在播种期间施用 KH（每 1 公斤种子 1.5 克）。分析了处理和未处理植物的生长、叶水比、叶绿素荧光、脂质过氧化、H2O2 含量、抗氧化酶和抗氧化能力。联合 AMF 和 KH 应用比单独处理对营养器官生长有更大的恢复作用。结合治疗，植物保持叶水状态和叶绿素荧光，而脂质膜的过氧化和 H2O2 含量降低。此外，超氧化物歧化酶和谷胱甘肽还原酶活性的增加防止了活性氧对细胞的损伤。在联合处理下生长的植物的总酚含量和抗氧化能力值显着更高。因此，与其单独应用相比，AMF 和 KH 的组合通过增加抗氧化酶和抗氧化能力增强了抗氧化防御系统，因此可用于促进植物生长。在联合处理下生长的植物的总酚含量和抗氧化能力值显着更高。因此，与其单独应用相比，AMF 和 KH 的组合通过增加抗氧化酶和抗氧化能力增强了抗氧化防御系统，因此可用于促进植物生长。在联合处理下生长的植物的总酚含量和抗氧化能力值显着更高。因此，与其单独应用相比，AMF 和 KH 的组合通过增加抗氧化酶和抗氧化能力增强了抗氧化防御系统，因此可用于促进植物生长。