UC San Diego

The circadian clock is an internal time-keeping mechanism that allows an organism to anticipate external changes by synchronizing its biological processes with the environment. In plants, previous evidence showed that the circadian clock function, although intrinsic to each cell, is compartmentalized in different tissues and that these tissue-specific clocks are organized in a hierarchical fashion. However, the function of cell-intrinsic clock components in each tissue is not well known. In this thesis, we developed a tissue-specific estradiol-inducible system for Arabidopsis thaliana aiming to better understand the role of clock proteins in a tissue-specific manner. We identified gene promoters that are active only at the shoot apex, root, or leaf tissues. We also experimentally confirmed the tissue-specific activities of these promoters and created conditional overexpression constructs for core clock genes. Additionally, we discussed possible phenotypes that could result from clock genes overexpression in each tissue. The strategy developed in this study provides a useful tool that could be universally implemented to study tissue-specific functions of any gene of interest.