Table III.
Enzymatic activities (in μmol g−1 fresh wt min−1 for MDH, ICDH, PEPC, GGPDM, LDH, and PDC, and in nmol g-1 fresh wt min−1 for CS, aconitase, fumarase, and CA) in root tip homogenates from Fe-sufficient and Fe-deficient sugar beet
| Enzyme | +Fe (0–10 mm) | −Fe
|
−Fe YZ/+Fe | −Fe WZ/+Fe | |
|---|---|---|---|---|---|
| YZ | WZ | ||||
| MDH | 6.84 ± 0.48 | 112.10 ± 24.60 | 25.30 ± 2.01 | 16.4 | 3.7 |
| CS | 0.036 ± 0.021 | 1.611 ± 0.360 | 0.133 ± 0.010 | 44.8 | 3.7 |
| Aconitase | 282 ± 65 | 1560 ± 133 | 380 ± 140 | 5.5 | 1.3 |
| ICDH | 0.168 ± 0.048 | 2.391 ± 0.342 | 0.356 ± 0.030 | 14.2 | 2.1 |
| Fumarase | 381 ± 99 | 3340 ± 1100 | 594 ± 112 | 8.7 | 1.6 |
| PEPC | 0.222 ± 0.066 | 13.320 ± 2.520 | 0.542 ± 0.041 | 60.0 | 2.4 |
| CA | 13.921 ± 3.220 | 11.690 ± 2.301 | 21.883 ± 5.410 | 0.8 | 1.6 |
| G6PDH | 0.589 ± 0.070 | 2.270 ± 0.573 | 0.785 ± 0.127 | 3.8 | 1.3 |
| LDH | 0.016 ± 0.006 | 0.216 ± 0.059 | 0.087 ± 0.024 | 13.5 | 5.4 |
| PDC | 0.048 ± 0.024 | 0.288 ± 0.120 | 0.097 ± 0.026 | 6.0 | 2.0 |
Data are the mean ± se of five replicates. In the control roots no differences were found between enzymatic activities in the 0 to 5 mm and 5–10 mm fractions (data not shown). Because of this reason, only mean values corresponding to the root 0 to 10 mm section from the apex are given.