Caroline Dean

My work focuses on how the environment influences the timing of flowering, the switch from vegetative to reproductive development in plants. Using the reference plant Arabidopsis thaliana we have combined genetics and molecular techniques to define the pathways regulating the switch to flowering. We have studied how this transition is promoted by prolonged cold, a process known as vernalization. Our work has revealed that plants 'remember' they have experienced winter through a conserved Polycomb chromatin mechanism. We have also discovered novel functions for RNA processing components in chromatin silencing mechanisms and elaborated co-transcriptional mechanisms linking RNA processing and stability with transcription. We are continuing to dissect the different facets of vernalization with the goal of generating a quantitative model that reveals how the chromatin silencing is induced by low temperature and how individual components of the chromatin silencing network are integrated into a robust whole. We are also examining the evolution of the flowering pathways and defining the molecular variation that has enabled Arabidopsis accessions to adapt to growth in a wide range of climates. Our findings have implications for epigenetic silencing, co-transcriptional regulation and molecular evolution in many organisms.