Figure 4.

Influences of CAT (a scavenger of H₂O₂) on the generation of H₂O₂ (a) and the biosynthesis of RA (b) in the suspension cultured cells treated by SA and/or exogenous H₂O₂. 6-day-old suspension cultured cells treated with CAT (100 U) 30 min before SA treatment were harvested at 8 h (for H₂O₂ analysis) and 2 d (for RA analysis) later, and the H₂O₂ and rosmarinic acid contents were then determined. The SA concentration is 22.5 mg/L. The exogenous H₂O₂ concentration is 10 mM. Values are means of three independent experiments. Bars represented standard errors. Different lowercase letters represent the significant differences between the concentrations of H₂O₂ (a) and RA (b) after each treatment at the level of 5%.