From weeds to crops: genetic analysis of root development in cereals.

Root development of Arabidopsis, Zea mays (maize) and Oryza sativa (rice) differs in both overall architecture and the anatomy of individual roots. In maize and rice, the post-embryonic shoot-borne root system becomes the major backbone of the root stock; in Arabidopsis, the embryonic root system formed by a simple primary root and its lateral roots remains dominant. Recently, several specific root mutants and root-specific genes have been identified and characterized in maize and rice. Interestingly, some of these mutants indicate that the formation of primary-, seminal-, crown- and lateral roots is regulated by alternative root-type-specific pathways. Further analyses of these unique pathways will contribute to the understanding of the complex molecular networks involved in cereal root formation.