Speaker: Dr Robert W. Smith.
Plant flowering is critical for the development of fruits and seeds that we require for food and biofuel production. The time taken for seedlings to start flowering is governed by the environment, such as day-length, temperature and light signals. Our understanding of how the environment regulates flowering comes from studies in the model plant Arabidopsis thaliana, where flowering in long days correlates with increased levels of FLOWERING LOCUS T (FT) mRNA. Here, I will show how a systems biology approach, combining experimental techniques with mathematical modelling, has helped improve our knowledge about the molecular mechanisms that regulate flowering. Previous work has highlighted how day-length, measured by the circadian clock, and light signalling regulates levels of CONSTANS (CO) protein that activates FT transcription. Recently, we have incorporated temperature into our model of flowering. The resulting analysis and experimental validation shows that temperature increases stability of CO protein during the day, increasing FT mRNA levels specifically at the end of long days. Thus, the model presented here can simulate flowering phenotypes in a number of experimental growth conditions and transgenic plants. Furthermore, the model may also highlight network structures that are general to many molecular pathways that control plant development.