Effects of Drought and Salinity Stress on Some Enzymatic Traits in the Leaves of Oleaster (Elaeagnus angustifolia L.)

Since the most of Iran's territory falls under arid and semi-arid regions, utilizing plants resistant to salinity and drought stress can provide new opportunities for exploiting the country's challenging climates. This study aimed to investigate the effects of different levels of drought and salinity on certain enzymatic traits in the leaves of one-year-old oleaster seedlings. A factorial pot experiment was conducted with two factors: drought at three levels (control, 66%, and 33% of field capacity) and salinity at four levels (control, 4, 8, and 12 dS/m) in the greenhouse of the Forestry and Forest Economics Department at the University of Tehran. The statistical design used was a completely randomized block design with three replications.In this research, the impact of drought and salinity treatments on the activity changes of catalase and superoxide dismutase (SOD) enzymes, along with some physiological traits, was examined. The results indicated that drought and salinity stress's main and interactive effects on the measured traits were significant. The activities of catalase, SOD, and proline increased due to drought and salinity stress; the highest levels of these traits—catalase (16.8U/mgpr), SOD (26.16 U/mgpr), and proline (235M/m)—were observed under the treatment of 33% field capacity combined with 12 ds/m salinity. Based on the results obtained, it can be concluded that the oleaster plant possesses an efficient antioxidant system that mitigates the effects of salinity and drought stresses. The increase in the activity of antioxidant enzymes and the accumulation of proline under stress conditions indicate that this plant can partially cope.