Arabidopsis FLU mutant with damaged regulation can survive only either in a continuous darkness (protochlorophyllide is not dangerous in the darkness) or under continuous light, when the plant is capable to convert all produced protochlorophyllide into chlorophyll and do not overaccumulate it despite of the lack of regulation. In barley Tigrina mutant (mutated on the same gene,[9]) light kills the majority of the leaf tissue that has developed in the darkness, but part of the leaf that originated during the day survives. As a result, the leaves are covered by white stripes of necrotic regions, and the number of the white stripes is close to the age of the leaf in days.