The shoot meristem as a site of continuous organogenesis

In higher plants, organ formation occurs throughout life. This remarkable process occurs at a collection of stem cells termed the shoot meristem. The shoot meristem originates during embryogenesis and is later responsible for generating the above-ground portion of the plant. The shoot meristem can be thought of as having two zones, a central zone containing meristematic cells in an undifferentiated state, and a surrounding peripheral zone where cells enter a specific developmental pathway toward a differentiated state. Recent advances have revealed several genes that specifically regulate meristem development in Arabidopsis. The function of these genes and their genetic interactions are described.