| Citation | The life cycles of most plants are synchronised to the passing seasons by responding to changes in day length. Coupland initiated the use of molecular-genetic methods to study these photoperiodic responses in Arabidopsis thaliana. His major contributions are in defining the molecular mechanisms that enable plants to measure day length and in explaining how these processes are related to the initiation of floral development. His work has provided a coherent model for how diurnal rhythms in transcription of regulatory genes combined with post-transcriptional regulation of protein stability by light induce flowering only under long summer days. |