Synthesis of Silver Nanoparticles Using Artemisia absinthium and Their Effect on the Physicochemical Properties of Ocimum basilicum under Salt Stress

Given the increasing salinization of soils due to water scarcity and saline water use for irrigation, the application of green silver nanoparticles synthesized from medicinal plants is proposed as an effective strategy to enhance plant tolerance to salt stress. In this study, silver nanoparticles were synthesized using an aqueous extract of Artemisia absinthium and applied to basil plants. The structural properties of the nanoparticles were identified using Ultraviolet-Visible spectroscopy, Transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results showed that the nanoparticles were spherical, with an average size of 23.68 nm and an absorption peak at 459 nm, confirming successful synthesis. Furthermore, XRD confirmed the crystalline structure of the nanoparticles. A factorial experiment was conducted using a completely randomized design with four replications in the greenhouse of Lorestan University. The experimental factors included salt stress at three levels (0, 50, and 100 mM) and silver nanoparticles at three concentrations (control, 10, and 50 mM). The results revealed that foliar application of green silver nanoparticles led to a significant improvement in growth parameters, including the fresh and dry weights of roots and leaves, as well as physiological traits such as phenol content, catalase and ascorbate peroxidase enzyme activities, and relative leaf water content Additionally, the results revealed that proline and malondialdehyde levels under salt stress, without silver nanoparticles, increased to 6.70 and 3.15 µM per gram of fresh weight, respectively. The findings suggest that biogenic silver nanoparticles enhance the salt stress tolerance of basil plants.