Résumé
Lateral root (LR) development allows the plant to explore the soil volume and capture water and minerals resources efficiently. In most species, annual or perenials, monocots or dicots, a large intrinsic variability in LR length is present. Such variability could be an adaptive trait enabling a greater plasticity and efficiency of the root system considering the spatial and temporal heterogeneity of soil resources (Forde 2009; Pagès 2011). While the molecular pathways involved in the development of primordia and young LRs (and in particular the contributions of auxin) are well characterized (eg. Lavenus 2013), we know surprisingly little about the mechanisms and actors involved in the variability of LRs. Because root growth rate is dependent on assimilate availability (Freixes 2002), we hypothesized that both auxin fluxes and sugar status of individual LRs could be involved in the variability of LR fate. We use maize plants as a model and have developped a phenotyping and computational pipeline to aquire and statistically analyse the LR growth patterns. Moreover, we have modified carbon and auxin fluxes to the LR using excision of all roots but the primary root and evaluated auxin and sugar status using biochemical and molecular markers.