Invilvement of several growth regulators during floral in duction of P. has ben studied here.
Inductive treatment induced repid variation in endogenous IAA and put levels. IAA peaking following application of inductive flowering Inductive treatment was also found in several materials/ but in those material it corresponded to the passage of global peroxidase activity through a minimum/ which is not the case here/ result not shown/ Temporary increases in put also have been registered after application of inductive flowering treatment /Galston/proposed that increase in put immediately preceded the activation of cell divition in meristems passing from the vegetative to the floral stage. It was difficult to see such a relationship in our case where floral development occurs much later . [Beginning of floral development,3 1/2 months later]Tarenghi / Found that free and conjugated polyamines predominated in the leaves initiated last[Unfortunately we have not discriminated between the different leaves used ]
The relationship between polyamine metabolism and flowering needs further investigation, but it was proposed that during the early events of flowering in Xanthium strumarium, a movement of polyamine occurred from young leaves to the buds and developing inflorescence / Moreover,a study on plant acclimation to cold temperature induced a transitory increase in put level. Than ,it would be interesting to know if temperature [cool] dependent plant need an acclimation process for floral induction such as photoperiod rhythm in other plant