The Control of Reproductive Onset and the Circadian Clock by GIGANTEA

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

The circadian clock controls the timing of many developmental and physiological processes in both plants and animals. The uncomfortable but familiar effects of jet lag experienced by air travelers is a direct result of the inability of the circadian clock to immediately reset to the new local time upon arrival. In plants, the circadian clock controls the onset of flowering and the timing of essential events like photosynthesis. In this way its function is crucial to efficient plant, and crop, growth and reproduction. Recent NSF-funded research has shown that two previously unconnected components of the plant clock, ZEITLUPE (ZTL) and GIGANTEA (GI), interact in a blue-light dependent way, by virtue of the novel photoabsorptive properties of ZTL. GI stabilizes the ZTL protein from degradation, defining a role for GI for the first time. This proposal will further define the biochemical function of GI by identifying which domains are effective for the interaction and stabilization of ZTL. A second aim is to identify other GI interactors, as it is likely that GI stabilizes other proteins, and may require other cofactors to function effectively. Techniques such as yeast two-hybrid analysis and mass spectrometric analysis of GI-TAP-tagged complexes will be used. Results from these studies will better define the molecular and biochemical components of the central oscillator of the clock in Arabidopsis. In turn, findings in this model system will lead to better understanding and control of crop physiology and reproduction. This work will provide an opportunity for the graduate student and postdoctoral researchers involved to learn contemporary molecular biology and plant biochemical techniques in an interactive environment. Additionally, undergraduates, who learn technical and molecular skills that they use later in their careers, are mentored by the more experienced lab workers. The research experiences of the personnel in this project will broaden their scientific expertise, and contribute to their development as future PI's, post-docs and teachers.