Effects of drought stress factors on antibacterial activity of two Triticum aestivum L. varieties

Triticum aestivum L. (Wheat grass), one of the members of Poaceae family, has been considered to be a very efficient therapeutic drug. In the present study, we propose to evaluate antibacterial effects of the two varieties of T. aestivum L. [cv. Tosunbey (drought tolerant) and cv. Sultan 95 (drought-sensitive)] which grown in three different stress conditions [(1) drought stress; (2) pre-treatment of seeds with acetyl salicylic acid; (3) drought stress and pre-treatment of seeds with acetyl salicylic acid]. The antibacterial activity of the ethanol extracts was assayed against five pathogens (Pseudomonas aeruginosa ATCC 27853, Proteus vulgaris ATCC 13315, Escherichia coli NRRL B-3704, Staphylococcus aureus ATCC 25923 and Bacillus subtilis ATCC 6633) by agar disc diffusion and micro broth dilution methods. The results showed that the ethanol extracts from the different studied treatments showed antibacterial activities, with the diameters of the inhibition zone ranging from 8 to 15 mm and minimum inhibitory concentration ranging from 2.5 to 20.0 µg/mL, respectively. The highest antibacterial activity, against B. subtilis ATCC 6633, was demonstrated by the extract of T. aestivum cv. Sultan 95, which grown in conditions where drought stress and pre-treatment of seeds with acetyl salicylic acid were combined.