Table 3. Effect of exogenous trehalose on the levels of non-enzymatic antioxidants (ascorbic acid, AsA and glutathione, GSH) and their redox ratios (AsA/DHA, GSH/GSSG) in rice seedlings with or without Cu stress.
| Duration | Treatment | Total AsA (nmol g−1 FW) | AsA/DHA ratio | GSH (nmol g−1 FW) | GSH/GSSG ratio |
|---|---|---|---|---|---|
| Day 4 | Control | 3979.25 ± 68.80c | 3.68 ± 0.51b | 492.56 ± 27.33a | 31.04 ± 3.71c |
| Tre | 4133.52 ± 199.36c | 4.83 ± 0.26c | 462.74 ± 32.20a | 32.04 ± 3.07c | |
| Cu | 2412.68 ± 215.14a | 1.21 ± 0.24a | 815.54 ± 69.93c | 17.38 ± 1.26a | |
| Tre+Cu | 3344.98 ± 294.46b | 3.16 ± 0.47b | 767.92 ± 57.03b | 20.07 ± 0.56b | |
| Day 7 | Control | 4264.65 ± 213.20c | 4.86 ± 0.63c | 573.38 ± 41.18a | 33.22 ± 0.15c |
| Tre | 4401.74 ± 139.84c | 6.03 ± 0.64d | 580.56 ± 46.11a | 37.59 ± 4.43d | |
| Cu | 1981.15 ± 159.26a | 0.97 ± 0.18a | 992.46 ± 20.12c | 12.45 ± 2.31a | |
| Tre+Cu | 3829.16 ± 150.62b | 3.31 ± 0.31b | 632.80 ± 53.85b | 15.35 ± 1.07b |
Control, Tre, Cu, and Tre+Cu correspond to control, 10 mM trehalose, 100 μM CuSO4, and 10 mM trehalose + 100 μM CuSO4, respectively. AsA, ascorbic acid; DHA, dehydroascorbic acid (oxidized ascorbic acid); FW, fresh weight; GSH, reduced glutathione; GSSG, glutathione disulfide (oxidized glutathione).Values are means ± SD of three independent replications (n = 3). Different letters within the column indicate statistically significant differences between treatments, according to Duncan’s multiple range test (p < 0.05).