Table 2.
Pectin methylesterase and peroxidase in vitro activities from cell-wall ionically bound proteins of hypocotyl
| 10-d hypocotyl |
18-d hypocotyl |
|||
|---|---|---|---|---|
| − Cd | + Cd | − Cd | + Cd | |
| Cell-wall yield (%) | 3·4 ± 0·3 | 3·9 ± 0·4 | 4·2 ± 0·4 | 4·1 ± 0·5 |
| Cell-wall proteins (mg g−1 dry CW) | 2·4 ± 0·2 | 2·1 ± 0·2 | 1·0 ± 0·1 | 2·5 ± 0·2 |
| PME (μkatal g−1 dry CW) | 1·0 ± 0·1 | 1·6 ± 0·1 | 0·6 ± 0·1 | 1·0 ± 0·1 |
| Peroxidase (nkatal g−1 dry CW) | 70 ± 6 | 76 ± 8 | 120 ± 10 | 186 ± 14 |
Seedlings were grown in the presence (+ Cd) or absence (− Cd) of cadmium and harvested at 10 and 18 d (10 d and 18 d, respectively). Data represent the means ± s.d. (n = 3). Note the highest value of PME activity at 10 d while the peroxidase activity increased at 18 d. The CW % was calculated as the mass of dry CW (g) per 100 g of fresh hypocotyls.