The Arabidopsis petal: a model for plant organogenesis.

Organogenesis entails the regulation of cell division, cell expansion, cell and tissue type differentiation, and patterning of the organ as a whole. Petals are ideally suited to dissecting these processes. Petals are dispensable for growth and reproduction, enabling varied manipulations to be carried out with ease. In Arabidopsis, petals have a simple laminar structure with a small number of cell types, facilitating the analysis of organogenesis. This review summarizes recent studies that have illuminated some of the complex interplay between the genetic pathways controlling petal specification, growth and differentiation in Arabidopsis. These advances, coupled with the advantages of using petals as a model experimental system, provide an excellent platform to investigate the underlying mechanisms driving plant organogenesis.