Lateral Meristems

Abstract Radial growth of plants is the result of activity of the lateral meristems. These meristems, known as the vascular and cork cambiums, are active in areas of the plant where primary growth has ceased and are therefore referred to as secondary meristems. The lateral meristems encircle the body of the plant. They are distinguished from apical meristems, which form the primary body of the plant, in several ways, but most noticeably in the proximity of the lateral meristem to the tissues that they produce. A proper understanding of lateral meristems may be considered as a problem of two parts: (1) how are cell divisions in the meristem regulated and (2) what controls the differentiation of new cells into specialized cell types. Key Concepts: Lateral meristems are referred to as the vascular cambium and cork cambium. Cell divisions in lateral meristems are responsible for increases in plant girth. Ordered cell divisions along vascular initials are required for organization of lateral meristems. Plant growth regulators like auxin, cytokinin and ethylene increase cambial activity.