Abstract: This experiment was designed to investigate cell growth,betacyanin accumulation and antioxidant enzyme activities changes of Portulaca grandiflora under different plant regulators.The results were shown as follows:Best cell growth and betacyanin accumulation was observed in MS medium containing 1.0 mg/L 2,4-D and 0.5 mg/L 6-BA.2,4-D significantly enhanced the activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) involved in reactive oxygen species (ROS) metabolism,suggesting that ROS mediated signal transduction pathway prominently exists in 2,4-D-induced betacyanin biosynthesis in cells of P.grandiflora. These results laid the foundation for further producing betacyanin by plant cell culture and studying betacyanin biosynthesis regulation mechanism in plant cell.

Key words: Portulaca grandiflora Hook, cell culture, 2,4-D, betacyanin, antioxidant enzyme