In sunflower exposed to a low R:FR ratio, Kurepin et al. (2007b) demonstrated higher endogenous levels of GA; with significantly increased levels of the inactive GA8 and GA20 , in leaf tissue.The situation in poinsettia is very similar to this.The detection of high levels of GA3 in poinsettia, similar to the GA1 contents, suggests that the side chain leading to GA3 is highly active in this species (Table 2).This has been demonstrated also in some other crops such as Marah marcocarpus, apple (Malus domestica) and maize (Zea mays)