• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.57-61
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• 1997

We investigated changes in the superoxide dismutase (SOD) activity and SOD isoenzyme pattern in suspension cultures of tomato (Lycopersicon esculentum), which were compared with those of intact tomato plants. two grams (fr wt) of cells subcultured at 15-day intervals were inoculated into 50 mL MS medium containing l mg/L 2,4-D and 30 g/L sucrose in a 300 mL flask and maintained at $25^{\circ}C$ in the dark (100 rpm). The cell growth reached a maximum at 20 days after subculture (DAS), followed by a rapid decrease with further cultures. The cell colour changed from white to black from 23 DAS. The intracellular SOD activity (units/g cell dry wt) was significantly increased from 23 DAS and reached a maximum at 28 DAS (52,400 units), followed by a decrease with further cultures, whereas the extracellular SOD activity showed a maximum at 25 DAS (27,800 units/50 mL medium). The total SOD activity per flask showed a maximum at 25 DAS (35,700 units), in which the extracellular SOD activity occupied about 75%. The tomato cultured cells had four SOD isoenzymes and their patterns were well correlated with SOD activity without a qualitative change during the cell cultures. The intact tomato plants had an additional CuZnSOD isoenzyme, showing the different isoenzyme patterns from cultured cells.