The impact of salicylic acid on some physiological responses of Artemisia aucheri Boiss. under in vitro drought stress

Salicylic acid (SA) is an important plant regulator which is involved in growth, development, and response to stress. This study was aimed to evaluate some physiological and biochemical responses of Artemisia aucheri Boiss. under drought stress after exogenous SA treatment. Experiment was performed in vitro. Polyethylene glycol (PEG/6000) with 0, 2 and 4 % (w/v) was used in MS medium to simulate drought stress and different concentrations of SA (0, 0.01 and 0.1mM) were added. After four weeks, SA alleviated the negative effects of PEG on dry and fresh mass as well as chlorophyll and carotenoid contents. Under drought stress, application of SA decreased storage polysaccharides and increased soluble carbohydrates respectively. Although PEG had no significant effect on flavonoid content, it increased significantly anthocyanin and total phenol content, total antioxidant capacity, PAL (phenylalanine ammonia-lyase) and TAL (tyrosine ammonia-lyase) activity and SA treatment improved these parameters significantly. According to the current data, it was concluded that SA increased drought tolerance of Artemisia aucheri by increasing biosynthesis of phenolic compounds, improvement of TAL and PAL activity as well as also by increased content of soluble carbohydrates.