ZTL Background Information Arabidopsis development is mediated by several environmental stimuli. Light plays an important role in many developmental processes, including photosynthesis, chloroplast biogenesis, leaf initiation, and floral induction (1). Several light sensitive proteins are thought to mediate the transition from vegetative to floral development in response to photoperiods. CONSTANS (CO) promotes flowering in response to long photoperiods. When CONSTANS is mutated, flowering is delayed during long photoperiods, but is not affected during short photoperiods (2-4). ZEITLUPE (ZTL) and FKF1 influence flowering by modulating the circadian clock in Arabidopsis (5,6).
