Fig. 6

Effects of different treatments on antioxidant enzyme changes in rice seedlings under water stress. Roots were collected to assay CAT (a), SOD (b), APX (c), and POD (d) after 3 h of treatment with non-water stress (Con) or water stress. For the c-PTIO, PEG + c-PTIO, and PEG + L-NAME treatments, the rice seedlings were pretreated with NO scavenger (c-PTIO) or NOS inhibitor (100 μM L-NAME) for 3 h followed by non-water stress or water stress. Values represent means ± standard error (SE) (n = 6). Different letters indicate significant differences at P < 0.05. Con indicates control treatment for each N nutrition, i.e., plants receiving non-water stress