Effects of seed pre-treatment of savoury (Satureja Hortensis) with salicylic acid and silicon nanoparticles under lead heavy metal stress

Abstract This study including two different experiments carried out with the aim of the evaluation of the effects of seed priming with salicylic acid and silicon nano-particles on germination, growth and physiological properties of savory seedling under lead abiotic stress condition based on factorial design. Factors including seeds pre-treatment with different concentrations of silicic acid (0, 0.5, 1 and 2 mM) and silicon nano- particles (0, 0.05, 0.1 and 0.15 mM ) and growing seeds under lead contamination with 0, 2, 4 and 8 mg/l concentrations. Results indicated that increasing lead concentration decreased seed germination and rate, shoot dry weight, weight and length indices, whereas increased proline content and enzymes activity. Results showed that the highest seed germination percentages (74.75 %), weight index (1403) and germination rate (87.7) were obtained in seed pretreated with salicylic acid, While the highest shoot dry weight (7,25 mg), length index (865,7) as well as proline content and peroxidase and catalase activities were recorded in seeds pretreated with nano-silicon particles under lead stress condition. The highest proline content and antioxidant catalase and peroxidase enzymes activity recorded in seeds treated with the highest concentrations of silicon nano-particles grown on media containing the highest concentrations of lead.