1. Investigate physiological changes of A. tumefaciens at the stationary phase of growth.
2. Investigate the effect of 4 ROSs, i.e., hydrogen peroxide (H2O2), menadione, tert-butyl hydroperoxide (tBOOH), and cumene hydroperoxide (CuOOH) on DNA, RNA, and total protein contents, and membrane permeability of A. tumefaciens.
3. Elucidate the function of catalases in protection of A. tumefaciens from ROS