Comparative assessment of AGAMOUS function in the Brassicaceae

The MADS-domain transcription factor AGAMOUS (AG) is required for specification, differentiation and meristem determinacy of floral reproductive organs in Arabidopsis thaliana. Our group has generated evidence to indicate that AG controls the expression of photosynthesis related gene expression, including genes required for stomatal development. Although the roles of AG during specification and determinacy are likely conserved in eudicots, the requirement for AG during differentiation, which includes the establishment of the silique as a photosynthetic organ, in other eudicots is unclear. To address these questions, we are performing comparative developmental and functional genomics experiments between A. thaliana and Cardamine hirsuta, which last shared a common ancestor ~32 million years ago. We have generated C. hirsuta and A. thaliana transgenic lines that facilitate an inducible knock-down of AG activity, which we will use to perform comparative transcriptomic assays. In addition, we will perform comparative in vivo protein-DNA binding profiling experiments to identify the targets of each orthologue. We will overlay these data with phenotypic assessments following disruption of AG activity in both species. This work will reveal the conserved and diverged activities of AG and the flexibility of the underlying gene regulatory network.