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Department of Plant Sciences



Supervisor: Alex Webb (Plant Sciences


The circadian clock in all organisms is usually considered to run with a period of 24 hours and have a fixed speed. My laboratory has discovered that sugars, nicotinamide and Ca2+ signals all can change the speed of the clock, some signals make it go faster and some make it go slower (Dodd et al., 2007 Science 318, 1789 - 1791; Dalchau et al., 2011 PNAS 108, 5104 – 5109; Marti et al., 2018 Nature Plants 4, 690-698). We have new data that suggest these changes in speed of the circadian oscillator contribute to the process by which plants know the time of day (Hearn et al., 2018 Plant Physiology 178, 358-371). The process of the clock resetting to the time of day is known as entrainment. It is the mysterious process by which humans wake up at the same time each day, and plants open their stomata just before dawn, and move their leaves in anticipation of dusk. We want to take a new approach to understanding how the circadian clock adjusts its timing to match that of the day and night cycle. We will generate plants in which we can transiently activate or switch-off selective circadian oscillator genes (chemical induction of gene activity or transient activation of RNAi), use optogentics to transiently activate protein degradation and chemical intervention to transiently interfere with phosphorylation and translation to investigate how changes in activity of clock components affect the period and phase of  the oscillator and how this affects entrainment. Through this approach we hope to gain a mechanistic and theoretical understanding of the molecular basis of clocks adjusting to their environment.