Phytohormone-Mediated Induction of Red Colour in the Flower Florets of a Cultivar of Dyer’s Saffron (Carthamus tinctorius)

Gibberellic acid was fed to a homogenate of Mogami-Benibana, a cultivar of dyer’s saffron (Carthamus tinctorius), at a 100 μᴍ level. After incubation for 60 min at 25 or 37 °C, the effect of externally supplied gibberellic acid on enzyme activities and the glucose level were investigated. Gibberellic acid enhances the activity of glucose oxidase by about 52%. It induces also a weak (9%) increase of glucosidase activity. Gibberellic acid increases the glucose content by about 6% during the initial 30-min incubation. The results relate to the red colour appearance in Mogami-Benibana at the later stage of blooming.