The structure and position of nectaries, which secrete nectar and attract pollinators to flowering plants, varies widely. In their investigation of nectary evolution, Lee et al. have discovered that a transcription factor– CRABS CLAW (CRC), the ancestral role of which is in carpel development – was co-opted to regulate nectary development in eudicots (plants with two embryonic leaves) when nectaries became associated with floral reproductive organs (see ). They show that CRC expression, which is required for nectary development in the eudicot Arabidopsis, is conserved in the morphogenetically different nectaries of other core eudicots, but not in those of a basal eudicot –the ancestors of core eudicots. CRC expression is also required for nectary development in the two major eudicot phylogenetic lineages. Shared CRC expression in diverse nectaries, suggest Lee et al., is comparable to shared gene regulation during the development of different eye types.
