Influence of polyamines on growth of hairy root cultures of witloof chicory (Cichorium intybus L. cv. Lucknow local) and formation of coumarins

The effect of polyamines (putrescine, spermidine, and spermine) was examined for growth and production of two coumarins, esculetin and esculin, in the hairy roots of chicory (Cichorium intybus L. cv. Lucknow local). Of the polyamines administered, 1.5 mM putrescine alone resulted in a 2.3-fold higher increase in the growth of hairy roots as well as in the production of esculetin and esculin, which was 3.37 times more than that of the control on day 21. The endogenous level of conjugated putrescine was more than fivefold that of free putrescine levels in untreated samples. The production of esculetin and esculin in hairy root cultures strictly correlated with growth in all of the treatments. Putrescine at 1.5 mM resulted in a greater length of primary root ( 18.29 +/- 1.37 cm) compared with the control (10.96 +/- 0.82 cm) and more secondary and tertiary roots. This study also provides insight into the morphogenetic changes that occur in roots in response to the external supply of polyamines.