The present study was performed to investigate the regulatory role of selenium (Se) in the antioxidant defense system, Na⁺ uptake, and essential oil (EO) production of Stachys byzantine (S. byzantine) under salt stress. For this purpose, a greenhouse study was conducted in a factorial experiment based on a randomized complete design with three replications. The studied factors included foliar-applied Se (0, 4, 8, and 16 mg L⁻¹) and salinity (0, 30, 60, and 90 mM NaCl). Malondialdehyde, H₂O₂, electrolyte leakage, oxidized glutathione (GSSG), ascorbate peroxidase (APX), catalase (CAT), and superoxide dismutase (SOD) significantly decreased by increasing salinity. Conversely, the chlorophyll content and glutathione (GSH), as well as monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) activities, represented noticeable decreases. However, Se supplementation alleviated the oxidative stress by activating some enzymes involved in the ascorbate–glutathione (AsA-GSH) cycle, including APX, DHAR, MDHAR, and GR activities, which further enhanced the activities of CAT and SOD. Exposition to Se also modulated the redox state by reducing GSSG while enhancing AsA and GSH contents when compared to non-Se supplemented salt-stressed S. byzantine plants. Mild salinity stress (30 mM NaCl), especially when combined with Se treatments, resulted in the highest production of the EO of S. byzantine. The findings of this study suggest the use of Se treatment as an efficient method for increasing the resistance of S. byzantine to salinity by reducing the damage to oxidative stress, activating antioxidant enzymes, modulating the redox state, and finally, improving the production of EOs.

本研究旨在研究硒 (Se) 在盐胁迫下对Stachys byzantine ( S. byzantine )的抗氧化防御系统、Na ⁺吸收和精油 (EO) 产生的调节作用。为此，在基于随机完整设计的析因试验中进行了一项温室研究，重复三次。研究的因素包括叶面施硒（0、4、8 和 16 mg L ^-1）和盐度（0、30、60 和 90 mM NaCl）。丙二醛，H ₂ O ₂、电解质泄漏、氧化型谷胱甘肽 (GSSG)、抗坏血酸过氧化物酶 (APX)、过氧化氢酶 (CAT) 和超氧化物歧化酶 (SOD) 通过增加盐度而显着降低。相反，叶绿素含量和谷胱甘肽 (GSH) 以及单脱氢抗坏血酸还原酶 (MDHAR)、脱氢抗坏血酸还原酶 (DHAR) 和谷胱甘肽还原酶 (GR) 活性显着下降。然而，硒补充剂通过激活参与抗坏血酸-谷胱甘肽 (AsA-GSH) 循环的一些酶，包括 APX、DHAR、MDHAR 和 GR 活性来缓解氧化应激，进一步增强了 CAT 和 SOD 的活性。与非硒补充盐胁迫的拜占庭沙门氏菌相比，暴露于硒还通过降低 GSSG 同时提高 AsA 和 GSH 含量来调节氧化还原状态植物。轻度盐度胁迫（30 mM NaCl），尤其是与硒处理相结合时，导致拜占庭链球菌的 EO 产量最高。这项研究的结果表明，硒处理是一种有效的方法，可以通过减少氧化应激的损害、激活抗氧化酶、调节氧化还原状态，并最终提高 EO 的产生来提高拜占庭沙门氏菌对盐度的抵抗力.