Roots are responsible for the acquisition of water and nutrients, the stable anchorage of the plant into the soil and the interaction with the rhizosphere. To efficiently serve these functions, the root system is extended through root branching, which occurs by the development of lateral roots. The research group of Tom Beeckman has focused its research over the last decade on the early stages of lateral root development, so called Lateral Root Initiation (LRI) in the model species Arabidopsis. Recently alternative research strategies to get insight into complex developmental processes. The here proposed reasearch will make use of deep sequencing to study the process of root branching in taxa originating from different evolutionalry clades. The lab of Tom Beeckman has worked out a method to synchronously induce the initiation of new lateral roots in different species. Thies technique allows for precise sampling of plant tissue for RNA sequencing purpose. Comparative analysis of the obtained gene expression profiles in the different species will allow for assessing expression conservation of divergence across species, and determine which genes within a given gene family are candidate functional orthologs. Such genes will be futher functionally analyzed through reverse genetic studies.