The Effect of Salicylic Acid and Nitric Oxide Pretreatment on ‎Reducing the Toxicity of Zinc Nanoparticles in Phlomis tuberosa

In this study, the effect of salicylic acid and sodium nitroprusside on the toxicity of zinc oxide nanoparticles (ZnONPs) and zinc sulfate (ZnSO4) in Phlomis tuberosa was investigated. The purpose of this research was to investigate new methods of increasing the tolerance threshold of Phlomis plants under the influence of zinc oxide and zinc sulfate nanoparticles toxicity. This experiment was conducted in the form of a completely randomized design with three replications in the form of pot cultivation in a perlite bed, and the plants were harvested after 21 days of treatment. The measured factors included total chlorophyll, carotenoid, total phenol, flavonoid, the activity of phenylalanine ammonia lyase, catalase, superoxide dismutase, and ascorbate peroxidase. The results of the analysis of the variance of the data in the laboratory showed that the application of 1000 mgL-1 of zinc oxide nanoparticles or zinc sulfate caused more toxicity. The interaction effect of salicylic acid and sodium nitroprusside pretreatments on zinc oxide nanoparticles in Phlomis seedlings was significant and salicylic acid pretreatment increased the amount of proline in the treatment of zinc oxide nanoparticles. Phenol antioxidants increased significantly under the effect of zinc oxide and zinc sulfate nanoparticles, which was associated with an increase in the activity of the phenylalanine ammonia lyase enzyme. Salicylic acid pretreatment showed the greatest effect in the Phlomis plant compared to the combination of salicylic acid and nitric oxide.