Putrescine influences growth and production of coumarins in transformed and untransformed root cultures of witloof chicory (Cichorium intybus L. cv. Lucknow local)

The effect of putrescine on growth and production of two coumatins,
esculin, and esculetin in the transformed and untranstbrmed
roots of chicory (Cichorium intybus L. cv. Lucknow local)
was examined. To study the role of putrescine (Put) on
growth and production of coumarms, polyamine inhibitors
namely a-DL-difluromethylornithine (DFMO) and a-L- difluromethylarginine
(DFMA) were used at 1 mM levels. Treatment
with 1.5 mM of putrescine (Put) produced 1.96 - fold and
4.0 - lbld increase in the growth of transformed and untransformed
roots of chicory, respectively. The treatment with
polyamine inhibitors showed much lower growth, as well as
production compared with both 1.5 mM putrescine treatment
and control in both transformed and untransformed chicory
roots. The endogenous polyamines, both free and conjugated,
were studied over the whole culture period, and it was seen that
conjugated titers of all three polyamines viz., putrescine,spermidine
and spermine were higher than level of free polyamines,
throughout the culture period in both transformed and
untransformed roots of chicory. Treatment in which polyamine
inhibitors were used showed lower level of endogenous polyamines
as compared with the 1.5 mM putrescine treated sample
in both the systems. The treatment wherein putrescine was
added at 1.5 mM level showed maximum accumulation of endogenous
conjugated putrescine (2098.86 _+ 157.6 nmoles g-I
FW; 896.8 _+ 67.2 nmoles.g d FW), on the 14 th day in both
transformed and untransformed roots respectively. The production
of esculin and esculetin was strictly correlated with
growth in every treatment in both systems. Putrescine at 1.5
mM resulted in greater length of primary root in transformed
(18.3 _+ 1.4 cm) and untransformed (6.86 _+ 0.51 cm) as compared
with their respective controls (11 __+0_ .9 cm; 2.9 _+ 0. l cm)
and greater number of secondary and tertiary roots. This study
suggests that putrescine influences plant root development and
differentiation, and it also provides insight into the morphological
changes that occur in roots in response to the external
supply of polyamines.