Dr Alex Webb, University of Cambridge
Dr Alex Webb, Department of Plant Sciences at the University of Cambridge will deliver a seminar as part of the James Hutton Institute seminar series.
He is Reader in Cell Signalling the research in his lab is focused on the physiological benefits of the circadian clock and the signalling mechanisms by which the circadian clock regulates cell physiology.
To understand the biology of plants it is essential to understand how cells cope with the stresses caused by the rotation of the Earth and seasonal changes. Our goal is to identify hitherto unconsidered mechanisms and provide new understanding that can be used by plant breeders to develop crops to alleviate the major problems facing the planet, food shortage, energy production and water use. We are particularly interested in how plants measure time and how this information is integrated with stress signalling. Stress signalling is tightly linked to the daily rhythms of the plants so that the plant can make the appropriate responses to a stress signal, such as cold, dependent on the time of day the signal is perceived.
The research in my lab is focused on how interactions between the internal circadian clock and physiological and environmental signals provide physiological benefits to the plant (Dodd et al. 2005, Science 309, 630 – 633). We particularly focus on the signalling mechanisms associated with cell physiology and the association of these signalling networks with the molecular mechanisms of the circadian clock (e.g. Dodd et al., 2007 Science 318, 1789 -179). I will describe physiological and systems approaches that provide new insight in to how environmental signals (Dalchau et al.,2010 PNAS 107, 13171-13176) and cellular energy status (Dalchau et al.,2011 PNAS 108, 5104 – 5109) regulate circadian timing in plants.
I will also provide new data demonstrating that the circadian oscillator is regulated by Ca2+ signalling networks. In Eukaryotes there are circadian oscillations of cytosolic free Ca2+. The roles of these 24 h oscillations of Ca2+ are unknown and at first sight seem at odds with the rapid oscillations of Ca2+ which are usually investigated. We are investigating the generation and function of circadian oscillations of Ca2+ in the model plant Arabidopsis thaliana. We previously have reported that circadian oscillations of Ca2+ are driven by oscillations in the cellular concentration of cyclic ADPR (Dodd et al., 2007 Science 318, 1789 -179). I will describe physiological and systems approaches that provide exciting new data demonstrating that the abundance of circadian oscillator genes is regulated by Ca2+ signalling through the action of CALMODULIN-LIKE PROTEINS. Our data demonstrate that Ca2+ signals are part of the timing mechanism of the Arabidopsis molecular circadian oscillator.
This seminar will take place at The James Hutton Institute Dundee and will be broadcast live to the Aberdeen site.
