Cell lineage, cell signaling and the control of plant morphogenesis.

It is clear that cell-cell signaling is critical for the development of both root and shoot structures. Recently, several of the key gene products required for intercellular signaling have been defined, and the developmental processes regulated by cell-cell interactions are beginning to be elucidated. Surprisingly, these results suggest that the mechanisms by which plant cells communicate with each other may be quite distinct from those used in animal systems.