THE ARABIDOPSIS ROOT AS A MODEL TO STUDY PLANT DEVELOPMENT

With its straightforward amenability to genetic approaches, Arabidopsi s thaliana proves to be a powerful system to study biological processe s in plants. The root of Arabidopsis has several additional features w hich make it a good model system to study developmental processes. It has a largely invariant ontogeny and fixed cellular organization. Cont inuous cellular differentiation in the root meristematic region allows monitoring of developmental processes after embryogenesis. The Arabid opsis root is also amenable for experimental manipulation. The simplic ity of its organization allows large-scale mutant screens covering sev eral aspects of root formation and growth. Experimental manipulations have uncovered the existence of positional cues important for pattern formation. Together with the several classes of mutants and the ongoin g identification of genes these findings contribute to a better unders tanding of developmental processes at the cellular level. (C) Elsevier , Paris.