Table III.

Effect of Fe in the medium on respiratory characteristics of wt tobacco cells

TreatmentMediumRespirationcyt CapacityAOX Capacity
nmol O2 mg−1 dry wt h−1
ControlOld5771,22756
Fresh, +Fe5881,26245
Fresh, −Fe5991,27933
CysOld71475639
Fresh, +Fe56664537
Fresh, −Fe615106572

Three-day-old cultures were washed twice and suspended with either their original (old) growth medium or with fresh one-half-strength growth medium (which contains 50 μm Fe-EDTA) or with fresh one-half-strength growth medium without Fe-EDTA. Cells were then left untreated for 4 h or were treated with 1 mm Cys for 4 h prior to measurement of respiratory characteristics. Data are the mean from two independent experiments, both of which showed similar results.