Root organization and gene expression patterns

New tools of microscopy, molecular biology, and genetics are making it possible for biologists to study roots with new vigour. Such investigations have enabled plant biologists to notice the symmetry, pattern, and simplicity of root structures so that there is now an exciting rebirth in the study of roots. The literature of root biology, development and structure is vast. In this short review we will concentrate on describing our notion of how roots are organized structurally, and then discuss what is known about tissue- and zone-specific gene expression in roots.