Transcriptional Regulation of ELF4 Expression and Resetting of Circadian Clock by Light

Yale University, New Haven CT

Investigators

Abstract

Circadian rhythm is a roughly 24-hour cycle in the biochemical, physiological, or behavioral processes of living entities, including both plants and animals. The circadian clock plays a crucial role in plant biology, and hence in agriculture, because outputs controlled by the clock include the timing of germination, diurnal optimization of photosynthesis, and floral transition. Each has been shown to be crucial for plant fitness. The circadian rhythms can be synchronized by the day/night cycle so that plants can correctly anticipate dawn and dusk. Although the photoreceptors involved in perceiving the light signals have been well established, how the light signals are transduced from the photoreceptors to the central clock remain largely unknown. In addition, little is known about how the rhythmic expression pattern of central clock genes and cyclic output responses (such as growth and photosynthetic activity of plants) are generated and controlled. The goal of this project is to investigate the role of a set of light- and circadian clock-regulated transcription factors (FHY3, FAR1, HY5, CCA1 and LHY) in transcriptional regulation of EARLY FLOWERING 4 (ELF4, a central clock component) gene expression and resetting of the circadian clock in response to changes in daily light conditions. It is expected that results from this study will provide fresh insights into the transcriptional circuitry underlying circadian clock regulation and lead to a better understanding of the physiology and reproduction in higher plants. In turn, the obtained information has the potential to be used for future application in optimizing growth of crop plants (such as increased fitness, increased hybrid vigor and latitudinal growth limit). This project will also provide excellent training opportunities for school children, undergraduate, graduate students and postdoc fellows.