Irrespective of that, flavonoids working as UV screeners and reactive oxygen species (ROS) scavengers , are of central importance in the context of UV acclimation(see review of Falcone Ferreyra et al.,2012;Gould,2004).Flavonoid synthesis depends on light intensity as well as on light quality (Feinbaum etal.,1991). More-over, we point out that light intensity and light quality influence the ability to accumulate epidermal flavonols during and after UV exposure. It is conspicuous that the FLAV-index(Fig. 6) and the total flavonoid concentration followed a similar trend as affected by different light intensities where as this was not the case when analyzing the effect of light quality . In contrast to light intensity high blue light increased the amount of epidermal flavonols (Fig. 10), where as the amount of anthocyanins and the total amount
of flavonoids were not affected(Table 2). Hereby,the results confirm that the light dependent accumulation of flavonoids is specific for each single component of the flavonoid family.