Growth Inhibition in Suspension-cultured Soybean Cells in the Presence of Ferulic Acid is Mediated through Spermine Accumulation

The effects of ferulic acid on the growth and polyamine levels of suspension-cultured soybean {Glycine max [L.] Merrill cv. Baek Tae) cells were investigated. When soybean suspension cells were cultured in the presence of ferulic acid, cell growth was significantly inhibited. Ferulic acid treatment resulted in a higher spermine level and lower levels of putrescine and spermidine in soybean suspension cells. The growth of soybean cells cultured in the presence of ferulic acid did not recover as a result of putrescine and spermidine addition. 5ʹ-methylthioadenosine, an inhibitor of spermine biosynthesis, caused a reduced level of spermine in soybean suspension cells cultured in the presence of ferulic acid. The growth of soybean cells cultured in the presence of ferulic acid was completely recovered after addition of MTA. Our cumulative results suggest that spermine accumulation is a factor causing growth inhibition of suspension-cultured soybean cells in the presence of ferulic acid.