International Symposium on Plant Photobiology

Halliday, K. (Keynote/plenary speaker)

Activity: Participating in or organising an event typesParticipation in conference


Using models to understand molecular signalling Robert W. Smith, A. Henrik Johansson, Joe R. Hemsted, Harriet Jones, Ramon Grima and Karen J. Halliday Centre for Synthetic and Systems Biology (SynthSys), School of Biological Sciences, Edinburgh University, Mayfield Road, EH9 3JD., Plant growth is optimised to local and seasonal variations in light and temperature. Indeed, the ability to adapt to environmental change is a principal determinant of reproductive success. Central molecular regulators of growth plasticity are the phytochrome (phy) photoreceptors that can dramatically alter the plant growth plan in response to external light signals. Recent work has shown that the light pathways are also a conduit for temperature signals, suggesting that these influential environmental cues utilise common pathway components to manipulate plant architecture (e.g. Foreman et al. Plant J. 2011 65(3):441-52; Franklin et al. PNAS. 2011 108(50):20231-5). Using the well characterised early phytochrome-activated signalling module, we used a modelling approach to understand the impact of temperature on molecular signalling in this prototypical pathway. This study has led to an improved understanding of how phytochrome operates and it has uncovered a thermally regulated growth switch. In moderate temperatures hypocotyl elongation is suppressed by light, but when temperature rises light promotes hypocotyl extension. Considering the signalling pathway as a whole, rather than focusing of specific molecular events, we now have a detailed understanding of the network features that underlie the temperature-activated switch. Modelling was a vital component in our approach as it provided non-intuitive predictions that were validated subsequently in the lab. In this study we developed a steady state model, however, Rob Smith will also provide two examples of dynamical models that link the circadian clock to external light-activated pathways. The initial model defined novel roles for FKF1 in the CO-FT flowering pathway (Song et al., Science 2012 336(6084):1045-9), while follow-on work led to the first model that incorporates photoperiodic regulation of flowering time and hypocotyl elongation. The use of models as a predictive tool is discussed.
Period3 Jun 20136 Jun 2013
Event typeConference
LocationEdinburgh, United Kingdom