Deciphering the genetic and molecular basis of cymose inflorescence development in Petunia – INFLO-DEV

INFLO-DEV: Deciphering the genetic and molecular mechanisms of cymose inflorescence development in Petunia

One of the major challenges in developmental biology is to understand how rewiring of GRNs (gene regulatory networks) and functional changes in key regulators in these networks have shaped diversity during evolution. Plants have evolved a wide diversity of body plans, including in their inflorescence architecture, the branching structures that bear the flowers. Besides of interest for fundamental research, understanding inflorescence development has also a huge societal interest since it directly influences the number of flowers (and thus fruits/seeds) that are produced in agricultural species that feed the human race. Four main types of inflorescence architecture can be distinguished, called solitary flowers (e.g. tulips), racemes (e.g. Brassica species), cymes (e.g. tomato) and panicles (e.g. rice). While raceme inflorescence development has been studied in great detail in Arabidopsis, information is more fragmentary for some other types of inflorescences, such as cymes. In general, there is a major need to further diversify our plant models and gain access to functional data in a wider set of diverse species to understand the impact of molecular evolution on plant morphological diversity. In Petunia, which has a cyme inflorescence like tomato but less complexe, we have developed technology which allows to easily study the function of a large numbers of genes. In this project, we propose to further decipher the genetic and molecular basis of Petunia inflorescence development, which on the long term will contribute to our understanding of how GRNs have evolved in species with contrasting inflorescence architecture. We will do so by deciphering in detail the molecular role of the AP1/FUL genes, for which we previously discovered that they play a major role in petunia inflorescence development.