EFFECTS OF DIFFERENT DOSES OF EXOGENOUS GIBBERELLIC ACID ON TOTAL PLANT WEIGHT, LIPID PEROXIDATION, AND ANTIOXIDANT ENZYME ACTIVITIES OF EGGPLANT SEEDLING UNDER SALT STRESS

The present study investigated the effects of different doses of gibberellic acid (GA(3)) on Aydin siyahi eggplant variety exposed to salt stress. The study was conducted to determine how applications affect plant development and metabolic activity. Eggplant seedlings were grown in a temperature-controlled hydroponic system in Hoagland nutrient solution. When they were 3 weeks old, they were exposed to salt stress (100 mM NaCl). Subsequently, they were treated with different doses of GA(3) (2.5, 5.0, 7.5, and 10 ppm). Leaves were harvested on the 15th day of the experiment. Fifteen days after the induction of salt stress, physiological (total plant weight) and biochemical (antioxidant enzyme activity, malondialdehyde [MDA] content, and chlorophyll content) changes were measured to determine the effect of the GA(3) treatments on plant growth and metabolic activity. In the NaCl plus high GA(3) treatment, the plant chlorosis level and degree of salt-induced damage decreased. In the NaCl plus high GA(3) (10 ppm treatment), plant development slowed due to salt-induced stress, but symptoms of stress, such as curling or chlorosis, were not detected in plant leaves. All doses the GA(3) treatments reduced antioxidant enzyme activities and MDA contents. In summary, the application of GA(3) to eggplant partially suppressed the adverse effects of salt stress on plant development and metabolic activities, and this effect was more apparent at a GA(3) dose of 10 ppm. Therefore, GA(3) may provide direct and indirect protection against salt stress.