ABSTRACT
Extractions provide a static picture of substances which are in a dynamic state, and at any time, their concentration is the outcome of their biosynthesis, accumulation, and metabolism. Owing to its central and historic role in their understanding of endogenous chemical control of plant development, early research concentrated on discovering correlations between auxin content and floral initiation. During vernalization of the Shuokan Chrysanthemum, there are changes in the content of unidentified auxins. Information concerning changes in endogenous cytokinin levels in relation to the flowering process is still very limited. In late varieties of Cichorium intybus, requiring a low-temperature treatment for flowering, increased cytokinin in the storage root is observed during chilling. Changes in endogenous inhibitors and abscissic acid in response to a vernalizing-cold treatment have been analyzed in a limited number of plants. Phenolamines are formed by amide bonds between a cinnamyl derivative and an amine such as putrescine, spermidine, spermine, or tyramine.
