Table 3.
The concentration of oxidative stress determinants, antioxidant molecules, and enzyme activities.
| Maize lines | MDA (μmol/gFW) | H2O2(nmol /mg FW) | FRAP (μlTrolox/gFW) | Polyphenols (mg GA/g FW) | Flavonoids (mg QA/g FW) | tASC(μmol/gFW) | ASC (μmol/gFW) | tGSH(μmol/gFW) | GSH (μmol/gFW) |
|---|---|---|---|---|---|---|---|---|---|
| tEU | 7 ± 0 | 68 ± 2 | 12 ± 1 | 0.39 ± 0.01 | 0.21 ± 0.01 | 1.1 ± 0.0 | 0.1 ± 0.0 | 0.3 ± 0.0 | 0.2 ± 0.04 |
| tAF | 5 ± 0 | 95 ± 5 | 13 ± 0 | 0.43 ± 0.01 | 0.24 ± 0.01 | 0.8 ± 0.0 | 0.2 ± 0.0 | 0.2 ± 0.0 | 0.1 ± 0.0 |
| EU | 6 ± 0 | 58 ± 3 | 13 ± 1 | 0.38 ± 0.01 | 0.22 ± 0.01 | 1 ± 0.0 | 0.3 ± 0.0 | 0.4 ± 0.0 | 0.3 ± 0.0 |
| AF | 5 ± 0 | 82 ± 4 | 11 ± 0 | 0.39 ± 0.01 | 0.20 ± 0.02 | 1 ± 0.0 | 0.2 ± 0.0 | 0.4 ± 0.0 | 0.3 ± 0.0 |
| B73 | 3 ± 0 | 150 ± 9 | 15 ± 1 | 0.40 ± 0.01 | 0.25 ± 0.02 | 2 ± 0.3 | 0.6 ± 0.1 | 0.4 ± 0.0 | 0.3 ± 0.0 |
| tEG | 7 ± 0 | 103 ± 3 | 7 ± 0 | 0.84 ± 0.04 | 0.44 ± 0.02 | 2.2 ± 0.1 | 1.3 ± 0.1 | 0.9 ± 0.1 | 0.8 ± 0.1 |
| EG | 4 ± 1 | 87 ± 4 | 8 ± 0 | 1.53 ± 0.17 | 1.04 ± 0.16 | 1.8 ± 0.1 | 1.0 ± 0.1 | 0.6 ± 0.0 | 0.6 ± 0.0 |
| Tolerant hybrids | 6 ± 1 | 89 ± 7 | 10 ± 1 | 0.55 ± 0.09 | 0.30 ± 0.05 | 1.3 ± 0.27 | 0.5 ± 0.25 | 0.5 ± 0.14 | 0.4 ± 0.14 |
| Non-tolerant hybrids | 5 ± 1 | 77 ± 7 | 10 ± 1 | 0.88 ± 0.32 | 0.56 ± 0.28 | 1.3 ± 0.18 | 0.6 ± 0.16 | 0.5 ± 0.06 | 0.4 ± 0.07 |
| EU hybrids | 6 ± 1 | 63 ± 3 | 12 ± 2 | 0.39 ± 0.02 | 0.21 ± 0.02 | 1.0 ± 0.03 | 0.2 ± 0.05 | 0.3 ± 0.04 | 0.2 ± 0.04 |
| AF hybrids | 5 ± 1 | 88 ± 7 | 12 ± 1 | 0.41 ± 0.02 | 0.22 ± 0.02 | 0.9 ± 0.06 | 0.2 ± 0.06 | 0.3 ± 0.06 | 0.2 ± 0.05 |
| EG hybrids | 5 ± 1 | 93 ± 9 | 7 ± 1 | 1.25 ± 0.37 | 0.80 ± 0.36 | 1.9 ± 0.16 | 1.1 ± 0.09 | 0.7 ± 0.08 | 0.7 ± 0.07 |
| Maize lines | SOD (Unit /mg protein.min) | CAT (μmol H2O2/mg protein.min) | POX (μmol oxidized pyrogallol/mg protein.min) | APX (μmol ASC/mg protein.min) | DHAR (nmol ASC/mg protein.min) | MDAR (μmol NADH/mg protein.min) | GR (μmol NADPH/mg protein.min) | GPX (μmol NADPH/mg protein.min) | |
| tEU | 50 ± 1 | 25 ± 2 | 0.7 ± 0.1 | 0.27 ± 0.02 | 7.2 ± 0.3 | 0.012 ± 0.001 | 0.007 ± 0.000 | 0.093 ± 0.016 | |
| tAF | 59 ± 3 | 26 ± 2 | 0.8 ± 0.1 | 0.26 ± 0.02 | 5.8 ± 0.2 | 0.006 ± 0.000 | 0.011 ± 0.001 | 0.067 ± 0.002 | |
| EU | 59 ± 2 | 25 ± 2 | 0.6 ± 0.1 | 0.27 ± 0.02 | 4.9 ± 0.2 | 0.015 ± 0.001 | 0.004 ± 0.000 | 0.110 ± 0.013 | |
| AF | 62 ± 2 | 25 ± 2 | 0.7 ± 0.1 | 0.26 ± 0.02 | 5.1 ± 0.3 | 0.005 ± 0.000 | 0.006 ± 0.000 | 0.040 ± 0.008 | |
| B73 | 29 ± 1 | 3 ± 0 | 0.4 ± 0.0 | 0.14 ± 0.01 | 3.8 ± 0.2 | 0.011 ± 0.000 | 0.007 ± 0.000 | 0.013 ± 0.000 | |
| tEG | 38 ± 3 | 28 ± 3 | 0.4 ± 0.0 | 0.20 ± 0.02 | 4.5 ± 0.2 | 0.026 ± 0.002 | 0.005 ± 0.000 | 0.015 ± 0.002 | |
| EG | 29 ± 2 | 11 ± 1 | 0.4 ± 0.0 | 0.20 ± 0.01 | 3.5 ± 0.3 | 0.014 ± 0.000 | 0.003 ± 0.000 | 0.032 ± 0.002 | |
| Tolerant hybrids | 49 ± 6 | 26 ± 1 | 0.6 ± 0.0 | 0.24 ± 0.02 | 5.8 ± 0.6 | 0.015 ± 0.004 | 0.007 ± 0.001 | 0.058 ± 0.022 | |
| Non-tolerant hybrids | 47 ± 7 | 19 ± 3 | 0.6 ± 0.1 | 0.24 ± 0.02 | 4.4 ± 0.4 | 0.012 ± 0.002 | 0.004 ± 0.001 | 0.056 ± 0.020 | |
| EU hybrids | 54 ± 4 | 25 ± 1 | 0.7 ± 0.1 | 0.27 ± 0.01 | 6.0 ± 0.8 | 0.014 ± 0.001 | 0.005 ± 0.001 | 0.101 ± 0.034 | |
| AF hybrids | 61 ± 5 | 25 ± 2 | 0.8 ± 0.0 | 0.26 ± 0.01 | 5.4 ± 0.2 | 0.005 ± 0.000 | 0.008 ± 0.002 | 0.053 ± 0.017 | |
| EG hybrids | 32 ± 6 | 18 ± 4 | 0.4 ± 0.0 | 0.20 ± 0.01 | 3.9 ± 0.4 | 0.019 ± 0.004 | 0.004 ± 0.001 | 0.025 ± 0.005 |
Data are averaged along the growth zones of leaves from well-watered seedlings of hybrids with different drought sensitivity and origin, and the inbred line B73. Leaf growth zones were divided in 10 equal segments and measurements were performed in each of the 10 segments. Three biological replicates (each consisting of 2–3 pooled plants) were measured for each line. Data are averages across all 10 segments of the growth zones and across the lines in the indicated group +/– SE (n = 20; for B73 n = 10; for EG n = 30). MDA, malondialdehyde; ASC, ascorbate; tASC, total ascorbate; GSH, glutathione; tGSH, total glutathione; FRAP, ferric reducing ability of plasma; SOD, superoxid dismutase; CAT, catalase; POX, peroxidase; APX, ascorbate peroxidase; DHAR, dehydroascorbate reductase; MDAR, monodehydroascorbate reductase; GPX, glutathion peroxidase; GR, gluthation reductase; FW, fresh weight; GA, gallic acid; QA, quercetin.