Abstract
In Arabidopsis thaliana, results from recent studies have begun shed light on the molecular mechanisms underlying clock-controlled circadian rhythms. In this context, we recently realized that each member of the small PRR family, including TOC1/PRR1, plays important roles close to the central oscillator (or within the input and/or output pathways). However, their individual molecular functions of PRRs have not yet been fully clarified. To this end, here we set up all possible transgenic lines each over-expressing constitutively a given one of the PRR genes (designated as PRR1-ox, PRR3-ox, PRR5-ox, PRR7-ox, and PRR9-ox), and their phenotypes were compared at once with each other, with special reference to "free-running circadian rhythm", "red light response during early photomorphogenesis", and "photoperiodic flowering time". Furthermore, we attempted to characterize transgenic plants mis-expressing a set of truncated form of PRR5 and PRR7. Taken these results together, we will discuss about the structure-functions of these PRR clock-components.
