Increase in peroxidase activity in tea callus in response to darkness, 2,4-dichlorophenoxyacetic acid and carbohydrates

The peroxidase (POD) reaction for the industrial synthesis of etoposide proceeds effectively when suspension-cultured plant cells are used as catalysts. Tea (Camellia sinensis) suspension cultures express higher POD activity and produce a higher yield of reaction products than those of other plant cells. We intend to investigate the conditions necessary to efficiently increase the POD activity in a suspension-cultured tea callus. Here we examined the influence of photoenvironmental conditions, phytohormones, and carbohydrates on POD activity in the callus grown on solidified medium. POD activity in the callus was increased 1) in the dark; 2) on medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) at 10 mg l−1; or 3) on medium containing 0.3 M sucrose and 0.1 M mannitol. The highest POD activity, achieved under the third set of conditions, was about 3.6-fold higher than that achieved on control medium (with 0.09 M sucrose).