*2.12. Antioxidant Enzyme Activities and ROS Accumulation under NaCl Stresses*

The antioxidant enzyme activities, the MDA content and the ROS accumulations in the *Bra034084* and *Bra029784* overexpressing cells were analyzed after 14 h of exposure to NaCl stresses. The results suggest that the antioxidant enzyme activities were greatly reduced by NaCl stresses compared with EV, as presented in Figure 11. The activities of SOD and POD were reported to be significantly higher in the *Bra029784* overexpressing cells than those in the *Bra034084* overexpressing cells, whereas the activity of CAT was enhanced in the *Bra034084* overexpressing cells. Moreover, the activities of CAT, SOD and POD were significantly higher under NaCl stress than those in the control. The MDA content was higher in the *Bra034084* overexpressing cells, while the contents of H2O2 and O2 − were not affected but were significantly higher than those of EV. The contents of ROS and MDA of NaCl stress were significantly higher than the control, as presented in Figure 11. These findings suggest that salinity stress negatively affected the activities of antioxidant enzymes but promoted the accumulation of ROS and MDA, which may activate the biosynthesis of the cell wall, and hence increase salt stress sensitivity.

**Figure 11.** The effect of salt stress on antioxidant enzyme activities, MDA and ROS accumulations of Bra034084 and Bra029784 overexpressing yeast cells. *Bra034084* and *Bra029784* overexpressing cells were exposed to 1 M salt stress and control (without stress) for 14 h at 28 ◦C. Superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide radicals (O2 −). Different letters indicate significant differences at *p* < 0.05.
