Rhizogenesis Lab - Projects ................................
control of lateral root development
Dr. Laurent Laplaze
are interested in lateral root formation and how root architecture is
controlled by environmental factors in order to maximise soil
exploitation in trees. Because forest trees are recalcitrant to
molecular and genetic approaches, we use Arabidopsis thaliana
as a model to isolate new genes involved in lateral root development.
Arabidopsis genome is completly sequenced (AGI, 2001) and numerous
functional genomic tools are available in this species. Moreover, the
key stages in lateral root formation in Arabidopsis have been defined
(Malamy and Benfey, 1997).
Our strategy is based on a GAL4 enhancer trap system set up in Dr Jim Haseloff's Lab in Cambridge (UK).
Exemple of enhancer trap pattern as marked by gfp expression
(green) in a lateral root primordia. Confocal section of a living Arabidopsis
root stained with propidium iodide (red).
We isolated enhancer trap lines generated by Dr. J. Haseloff's, Dr. S. Poethig's
and in our own lab for lateral root specific expression (Laplaze et
al., 2005). Molecular analyses of these lines allow us to identify
genes specifically expressed during lateral root development. Moreover,
these lines are powerful tools to manipulate lateral root development.
In collaboration with Pr Malcolm Bennett's lab
(Projet Alliance n°05752SM), we are using GAL4-mediated gene
transactivation to analyse the role of phytohormones during lateral
root initiation and development.