The study of the interactive effects of salicylic acid and salinity stress on induction of oxidative stress and mechanisms of tolerance in Ocimum basilicum L.

Studies have shown that salicylic acid (SA improves the resistance of the plant to environmental stress (heat، cold، drought and salt stress). In this research we studied the effect of salicylic acid on lipid peroxidation، sugars and the quantity of Na+، K+ ions in leaf and root of Ocimum basilicum under salinity stress. The plants were grown in pots until 4 leaf stages. Then، the leaves were sprayed with one of three concentration of salicylic acid (0، 0. 01 and 0. 1 mM SA) for 5 days and salt stresses at 3 levels (0، 100 and 200 mM NaCl) were treated for 5 days. Lipid peroxidation in leaf and root decreased significantly after treating with salicylic acid and salt water، but malondealdehyde increased significantly in root in 200 mM NaCl under the condition of the combination of the treatment with salicylic acid and salt water. Sugar and Na+ in leaf increased significantly with increasing salty stresses. Not only had the amount of sugar and Na+ decreased significantly under the combination of the treatment with salicylic acid and 100 mM NaCl، but also the amount of sugar increased with 200 mM NaCl in this condition. The amount of sugar and K+ in root increased significantly in the condition of salinity stress with 100 mM. The combination of the treatment with salicylic acid and salt water increased significantly the amount of sugar in root under salty stresses condition. Both 100 and 200 mM NaCl، as well as the combination of the treatment with salicylic acid and salt water، decreased K+ significantly، that is، the presence of salicylic acid enhanced the effect of salinity.