RESUMO
Objective: To analyze the effect of exogenous polyamine on the growth of Betula platyphylla suspension cells and triterpenoid accumulation. Methods: At the end of the growth stage, 0.1 mmol/L and 1.0 mmol/L putrescine (Put), spermine (Spm), and spermidine (Spd) were added to the suspension cells of B. platyphylla, the triterpenoid content and gene expression of lupeol synthase (LUS) related to the synthesis of triterpenoid were analyzed by chemical colorimetry and RT-PCR, respectively. Results: Except for the treatment with 1.0 mmol/L Spm, the cell viability, dry weight, and triterpenoid production in B. platyphylla suspension cells induced by Put and Spd were increased, and the dry weight and triterpenoid production of B. platyphylla cells were increasing with the extension of polyamine treatment time. Among them, dry weight and triterpenoid production were the highest after 2 d Put induction, which were 38.89% and 116.35% higher than those in the control, respectively. Triterpenoid production in B. platyphylla cells induced by polyamine was further confirmed by RT-PCR of LUS gene. Conclusion: Put could effectively enhance the growth of B. platyphylla suspension cells and triterpenoid accumulation.