Plantmeristemen

Plantmeristemen are regions of actively dividing, undifferentiated plant cells that drive growth in plants. They retain the capacity for indeterminate growth and give rise to new tissues and organs throughout the plant’s life. The main types are apical meristems at the tips of shoots and roots, which produce primary growth; lateral meristems such as the vascular cambium and cork cambium, which enable secondary growth and thickening; and intercalary meristems in some monocots, located at leaf bases or internodes, allowing rapid elongation after damage.

Meristematic cells are small, with dense cytoplasm and large nuclei and thin walls. They divide to form derivatives that differentiate into the three primary tissue systems: dermal (epidermis), ground (parenchyma, collenchyma, and sclerenchyma), and vascular (xylem and phloem). Primary meristems include the protoderm, ground meristem, and procambium. As plants mature, lateral meristems contribute to secondary growth by adding vascular tissue and protective layers.

Growth is regulated by hormones such as auxin and cytokinin and by environmental signals. Meristems are essential for ongoing organ formation, regeneration, and response to injury. In horticulture and plant biotechnology, meristematic tissue is used for cloning and tissue culture to propagate desirable genotypes.

Plantmeristemen are a defining feature of vascular plants, enabling continuous development from seeds to mature individuals and facilitating adaptation to changing environments.