Table 3.
Comparison on the activities of three C4 key photosynthetic enzyme after sudden heat shock (SHS) between at 0 h (aft 0) and 4 h (aft 4) in two maize genotypes grown under ambient or elevated CO2.
| OTCs | SHS | PEPC Activity (μmolm−2s−1) | ME Activity (μmolm−2s−1) | MDH Activity (μmolm−2s−1) |
|---|---|---|---|---|
| Ambient CO2 | ||||
| B76 | aft 0 | 15.5 ± 0.5(33.1 ± 1.6) | 3.7 ± 0.4(31.6 ± 0.5) | 7.9 ± 3.4(24.8 ± 3.3) |
| aft 4 | 19.7 ± 0.5(36.5 ± 1.5) | 20.6 ± 0.3(29.0 ± 0.1) | 14.9 ± 1.2(26.5 ± 0.4) | |
| %Increase | 27.1 | 456.8 | 88.6 | |
| B106 | aft 0 | 13.3 ± 0.7(32.8 ± 0.5) | 12.4 ± 1.1(24.6 ± 0.3) | 17.2 ± 0.3(26.1 ± 0.2) |
| aft 4 | 15.8 ± 0.7(36.6 ± 1.4) | 13.9 ± 0.7(27.7 ± 0.3) | 19.0 ± 2.7(28.9 ± 0.4) | |
| %Increase | 18.8 | 12.1 | 10.5 | |
| Elevated CO2 | ||||
| B76 | aft 0 | 13.6 ± 1.5(32.0 ± 0.7) | 10.9 ± 0.2(25.3 ± 0.4) | 12.1 ± 1.7(29.0 ± 1.2) |
| aft 4 | 17.9 ± 1.3(34.4 ± 0.9) | 18.1 ± 1.0(26.3 ± 0.6) | 20.9 ± 0.4(28.8 ± 1.5) | |
| %Increase | 31.6 | 66.5 | 72.7 | |
| B106 | aft 0 | 10.5 ± 1.7(32.2 ± 0.1) | 9.0 ± 0.6(26.7 ± 0.8) | 14.6 ± 1.7(28.6 ± 0.6) |
| aft 4 | 12.8 ± 1.0(31.9 ± 1.0) | 11.6 ± 1.6(29.2 ± 0.5) | 13.7 ± 0.9(31.6 ± 1.1) | |
| %Increase | 21.9 | 29.1 | −6.2 | |
Values in brackets stand for the activities of nonheated leaves. Percent increase were calculated as: [Activitiyaft4-Activityaft0/Activityaft0 * 100].