ABSTRACT
As basil occurs in the arid and semi-arid regions, the drought and salinity decrease the vegetative growth andleaf area. This research was carried out in Pakdasht private greenhouse to evaluate the effect of putrescine,spermine, and spermidine on quality and quantity of basil under conditions of salt stress. This research wasdone as a factorial experiment in a completely randomized block design with three replications. The treatmentsincluded application of putrescine, spermine, and spermidine at four levels (0, 50, 100, and 150 mg/l), salinitystress at four levels (0, 50, 100, and 150 mM), and control treatment. The results showed that the interactioneffects between polyamines, salinity, and concentration on plant height, fresh/dry shoot weight, fresh/dryweight of root, fresh/dry leaf weight, leaf chlorophyll content, catalase, peroxidase and guaiacol peroxidaseantioxidant enzymes, the ratio of K/Na ratio, ion leakage, and proline were statistically significant at 1% level.Interaction and simultaneous exposure of 150 mg/l spermidine and low salinity had a positive effect on all thestudied plant traits. In addition, the results showed that the concentration of 150 mM sodium chloride solutionreduced the mentioned traits. However, spermidine improved this condition, and symptoms of stress anddamages were less observed in spermidine-treated plants. Therefore, it can be used to withstand the oxidativestress of plants.