Table 4.
Effect of NO precursors on the activity of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) in wheat root challenged with Al.
| Treatments | Al-sensitive cultivar |
||
|---|---|---|---|
| SOD |
CAT |
APX |
|
| (U min−1 mg prot−1) | (µmol H2O2 min−1 mg prot−1) | (µmol ASC min−1 mg prot−1) | |
| Ctrl | 27.5 ± 0.7 aA | 402.9 ± 17.5 aA | 59.7 ± 2.1 aA |
| Al | 27.4 ± 1.1 aA | 417.4 ± 18.1 aA | 60.8 ± 2.3 aA |
| NO3−/Al | 41.0 ± 1.5 bC | 534.5 ± 12.1 bC | 78.5 ± 1.7 bC |
| Arg/Al | 33.8 ± 0.7 cC | 453.0 ± 30.2 aAB | 35.4 ± 2.0 dE |
| GSNO/Al | 26.7 ± 0.9 aA | 336.2 ± 9.1 cD | 49.7 ± 1.0 cD |
| Al-tolerant cultivar | |||
| Ctrl | 30.4 ± 0.7 aB | 475.0 ± 15.7 aB | 68.5 ± 1.8 aB |
| Al | 36.0 ± 1.4 bC | 555.1 ± 2.6 bC | 80.5 ± 1.4 bC |
| NO3−/Al | 26.9 ± 1.0 cA | 337.1 ± 11.7 cD | 51.2 ± 1.7 cD |
| Arg/Al | 64.8 ± 4.6 dD | 889.5 ± 29.5 dE | 69.4 ± 2.8 aB |
| GSNO/Al | 26.2 ± 1.6 cA | 330.7 ± 18.4 cD | 50.7 ± 2.6 cD |
Values are the means + SE (n = 4). Arg, L-arginine; GSNO, S-nitrosoglutathione; ASC, ascorbate. Distinct lowercase letters indicate significant difference among treatments within a cultivar while distinct uppercase letters indicate significant difference for a same treatment between cultivars.