The application of increasing NaCl concentra-tions significantly decreased EO yields (Fig. 2). The negative effectof salt stress on oil yield was also reported for other mint species(El-keltawi and Croteau, 1987; Tabatabaie and Nazari, 2007; Azizet al., 2008). This decline in oil yield under salt stress has beenattributed in part to the inhibition of the supply of cytokinin fromroots to shoots and subsequent alteration of the ratio betweenleaf cytokinin and abscisic acid (El-keltawi and Croteau, 1987).As shown in Table 2, twenty-eight compounds were identified,accounting for 99.2% of the total EO from control plants. The EOwas primarily made up of oxygenated monoterpenes and the con-trol contained pulegone as the main component (62.1%), followedby menthone (12.9%) and isomenthone (11.3%). It is of note thatsalt stress did not reduce the relative abundance of oxygenatedmonoterpenes in general. However, salt stress did affect the con-tent of pulegone and, most markedly, menthone. The application