Dean's research has been funded by the Biotechnology and Biological Sciences Research Council European Research Council, EU-Marie Curie and EMBO and focuses on research on gene regulation and the intersection of chromatin, transcription and non-coding RNAs. Her goal is to understand the chromatin dynamics that enable switching between epigenetic states and quantitative regulation of gene expression. This mechanistic analysis is focused on one gene encoding the floral repressor FLC. Epigenetic switching and quantitative regulation of FLC play a central role in seasonal timing in plants. This acceleration of flowering by prolonged cold is a classic epigenetic process called vernalisation.
Dean has made outstanding contributions in the study of developmental timing in plants. Her work has revealed the mechanism by which plants remember they have experienced winter, demonstrated novel RNA processing mechanisms controlling flowering and determined the molecular basis of natural variation in Arabidopsis flowering time. Her discoveries have broad significance in the fields of epigenetics, post-transcriptional regulation and molecular evolution. Dean has also made a massive contribution to the development of Arabidopsis as a model, establishing resources for genetic mapping and insertional mutagenesis, and providing physical maps that underpinned the sequencing of the genome.