Methyl jasmonate effects on volatile oil compounds and antioxidant activity of leaf extract of two basil cultivars under salinity stress

Basil (Ocimum basilicum L.) as an economic and culinary herb is used in traditional medicine. In this research, a pot experiment was conducted, as factorial based on randomized completely design with three replications, to examine the influence of methyl jasmonate (MeJA) on volatile substances and chemical components as well as antioxidant activity of leaf's extract from two commercial cultivars (Genove and Rubi) of sweet basil under salinity stress. The treatments were comprised MeJA (0 and 0.5 mM) and salinity stresses (0, 30, 60, and 90 mM). Using MeJA foliarly meaningfully raised the essential oil content in the Rubi cultivar at 0 and 30 mM of salinity and in the Genove cultivar just on 30 mM of salinity. MeJA treatment increased the essential oil content and also showed noticeable effects on the main components of the oils. The foliar application of MeJA raised the percentages of linalool and 1,8-cineole, whereas reduced the percentages of alpha-cadinol, alpha-bergamotene, beta-maaliene, and eugenol in the extracted oil. In both basil cultivars, the MeJA significantly enhanced the antioxidant activity. The highest antioxidant activities in the Rubi and Genove cultivars were obtained at 0 mM (control) and 60 mM of salinity with the MeJA application, respectively. In conclusion, the foliar application of MeJA caused to different responses in the cultivars and reduced the negative effects of salt stress.