Vegetative Apical Meristems.

A fascinating aspect of plant biology is that a small cell group is the origin of shoot systems as varied as redwood trees or Arabidopsis. The first recognition that shoot systems originate from small groups of cells was by Kaspar Wolff in 1759 (cited in Cutter, 1965). These small groups of cells are known as shoot apical meristems. Because the shoot apical meristem is the origin of the shoot, it can be described to make the shoot. The apical meristem makes the shoot through four functions: initiating new organs, initiating new tissues, communicating signals to the rest of the plant, and maintaining itself as a formative region. How these functions are integrated within the apical meristem to produce the shoot has been the question of many studies and provides continual intrigue. Many recent studies have focused on processes in floral meristems (e.g., Coen and Meyerowitz, 1991). Yet, before the floral (and inflorescence) meristem forms, the vegetative api? cal meristem is the shoot's source of cells. This earlier state