UC San Diego

Plants, like many organisms, possess the ability to synchronize their biological processes with the diurnal conditions of the surrounding environment. This ability is largely controlled by an internal time-keeping mechanism known as the circadian clock. Clock function is intrinsic to each cell in the plant organism and at the same time is compartmentalized in the form of tissue-specific clocks. In addition, previous studies have shown that these tissue-specific clocks are further organized in a hierarchical structure. Still, the tissue-specific role of core clock components is largely unknown and is the focus of ongoing research. In this thesis, we tested a previously constructed tissue-specific estradiol-inducible system in Arabidopsis thaliana, and we discovered results that suggested a need for modifying this system to yield more effective conditional tissue-specific gene expression. In addition, phenotyping experiments were conducted to test this systems capacity to overexpress core clock elements and it was observed that for certain clock genes, the timing of induction is an important factor that should be taken into consideration for future experiments utilizing similar conditional systems. Altogether, the approach outlined in this study poses a useful tool for not only elucidating the tissue-specific role of clock genes in plants, but also for investigating tissue-specific functions of any gene of interest.