Evolution of carnivorous traps from planar leaves through simple shifts in gene expression (Science)

When is a leaf not a leaf? When it’s a trap. Just about everyone, including Charles Darwin, has been fascinated by carnivory in plants, which involves the development of structures that capture or trap food. Whitewoods, Gonçalves, Cheng et al. investigated how traps form in the humped bladderwort Utricularia gibba. They imaged developing leaflet and trap primordia, examined expression of genes known to control leaf shape, overexpressed one of these (UgPHV1), and based on these findings developed models the recreate that development of the traps.  They found that multiple leaf forms can be generated simply by small changes in domains of gene expression, showing “how cup-shaped forms evolved multiple times independently from species with planar leaves.” (Summary by Mary Williams) Science  10.1126/science.aay5433