Changes in the content of phenolic substances during the growth ofNicotiana tabacum cell suspension culture

The dynamics of changes in the content of four groups of phenolic substances was investigated during the growth cycle of the cell suspension culture ofNicotiana tabacum by means of fractionation. The relative contents of free phenolic acids, their esters, phenolic glycosides, and phenole acids non-extractable with methanol changed in dependence on the growth phase of the culture. A sharp increase, especially in the content of ester- and glycoside-bound phenolics and to a lesser extent also of phenolics belonging to the other two groups, occurred at the end of the lag phase. Then, after a temporary decrease at the early linear phase, the level of phenolics in the three fractions representing bound forms considerably increased again at the late linear and early stationary phases. The synthesized phenolic substances were partially released from the cells into the cultivation medium, which contained 15 to 30 % of the total content of the phenolics in the culture at different phases of the growth cycle. Likely causes of these changes are discussed.