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Alex Webb

Contact to find out more about the individual studentships in the Circadian Signal Transduction group.  Use the 'How to apply' link to apply and for contact details about general questions.  See Google Scholar for publications.

Background

We perform cutting edge research to understand the biology of Plant Cells. 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. We use experimental approaches and also develop new systems biology approaches to provide new insight.

The research in my lab is focused on the interactions between the internal circadian clock and the physiology and metabolism of the cell. We have four main areas of research currently active in the laboratory. We investigate the role of NAD metabolism in the circadian clock. This is in collaboration with Bayer CropScience and builds on our finding that the small signalling molecular cADPR is part of the circadian network (Dodd et al., 2007 Science 318, 1789 – 179). We investigate the role sugars derived from photosynthesis in regulation of the circadian clock, as part of a wider programme of understanding the relationship between metabolism and circadian rhythms. These studies build on our recent findings that sugars entrain the circadian clock (Haydon et al. 2013 Nature 502, 689–692; Dalchau et al., 2011 PNAS 108, 5104 – 5109). We investigate how the circadian clock regulates cytosolic-free Ca2+ concentration and the role of Ca2+ binding proteins in regulating the transcription of circadian clock genes as part of a newly identified Ca2+ switch in the circadian system (Xu et al., 2007 Plant Cell 19, 3474 - 3490; Dodd et al., 2007 Science 318, 1789 - 1791). We demonstrated that circadian clocks provide considerable advantage to land plants (Dodd et al. 2005, Science 309, 630 – 633) and therefore we translate our basic findings in Arabidopsis to analyse of the role of circadian clocks in important crops such as barley and wheat. This work is performed in collaboration with Bayer CropScience and the National Institute of Agricultural Botany. We are also continuing to develop linear systems tools for analysis of circadian rhythms and a general toolkit for the biological Sciences (Herrero et al., 2012 Plant Cell 24, 428-443; Dalchau et al., 2010 PNAS 107, 13171-13176. This is a collaboration with Prof Jorge Gonçalves.

In addition to our work on circadian systems, we maintain an interest in Ca2+ signalling (e.g. Conn et al., 2011 Plant Cell 23, 240-257) with a particular emphasis on the circadian-gating of Ca2+ signalling (Dodd et al., 2006 Plant J. 48, 962 – 973) and the mechanisms of information encoding in Ca2+ signals (Martí et al., 2013 Plant Physiology 163, 625 – 634). We also collaborate with the Julia Davies’ group at Cambridge to investigate Ca2+ channel identity (Laohavisit et al., 2009 Plant Cell 21, 479-493; Laohavisit et al., 2012 Plant Cell 24, 1522-1533).

The lab is well equipped for circadian research. In addition to essential molecular biology and biochemistry equipment, we have specialist facilities for circadian analyses. These include three automated imaging and photon counting systems for luminescence measurements, two low background PMT systems for aequorin measurements, a 96 well plate fluorescence, luminescence and absorbance reader, a single cell FRET imaging workstation based on an Evolve camera for cameleon imaging, a real time PCR machine, a 16 camera automated leaf movement imaging system, a 6 channel infra-red gas analysis system for automated circadian measurement of stomatal movements and photosynthesis. We are housed in a new laboratory suite consisting of a biological darkroom, four imaging and electrophysiology rooms, a data analysis room and wet lab. We share these facilities with the group of Dr Julia Davies housing considerable expertise in Ca2+ signalling in one place. We have access to state of the art electrophysiology including planar bilayers, patch clamp, whole cell and MIFE apparatus. The lab is housed in an extremely well-equipped Department. We have an excellent plant growth facility and close links with the recently opened Sainsbury Laboratory which is house in the Botanic Gardens. The University of Cambridge offers a unique environment for research with around 500 researchers in plant sciences. Currently my laboratory consists of two technicians, one post doc and six graduate students.

I would be happy to discuss projects in detail with you. Below I outline the major areas we will pursue in the laboratory.

Title
Control of circadian period (fully funded)
Identification of components of the nitric oxide signalling pathway in Arabidopsis
Mathematical Modelling of the Regulation of Circadian Period
NAD and Ca2+ Signalling Mutants that Regulate the Circadian Clock
Phase oscillator models of circadian regulation by metabolites
Regulation of the Circadian Clock by Sugars
The contribution of plastic circadian period to circadian entrainment and plant performance