Changes in IAA,Phenolic Compounds,Peroxidase, IAA Oxidase,and Polyphenol Oxidase in Relation to Flower Formation in Crocus sativus

Changes in levels of IAA, phenolic compounds, peroxidase, polyphenol oxidase, and IAA oxidase activities in the corm and the apical bud of Crocus sativusL. during bud growth and development, with special emphasis on the flowering stage, were studied. In the bud, flower formation was accompanied by enhanced activities of peroxidase, polyphenol oxidase, IAA oxidase, and higher contents of phenolic compounds as well as lower levels of IAA. In the corm, during the flower formation, these enzymes showed an opposite behavior. Moreover, the contents of phenolics and IAA in the corm tissues during flower formation and growth were higher than at the other developmental stages. It may be concluded that the transition of saffron plants to flowering is correlated with peroxidase, polyphenol oxidase, and IAA oxidase. Furthermore, these enzymes might exert their roles in the regulation of flowering through their participation in IAA catabolism. The hypothesis of regulation of bud development by an interaction between phenolics and the enzymes involved in IAA catabolism is discussed.