Cork cambium

Cork cambium (also known as phellogen) is a type of meristematic tissue in plants that produces cork cells to provide protection and reduce water loss. It is one of the several layers of bark, located just outside the vascular cambium. The cork cambium originates from the secondary lateral meristems and plays a crucial role in the secondary growth of stems and roots in dicotyledonous and gymnosperm plants.

Formation and Structure

The cork cambium forms from the parenchyma cells located just beneath the epidermis or from the outer layers of the primary phloem. These cells undergo dedifferentiation to become meristematic, meaning they regain the ability to divide. Once the cork cambium is established, it starts to produce cork cells (phellem) towards the outside and sometimes phelloderm cells towards the inside. The cells produced by the cork cambium undergo several changes, including the deposition of suberin in their walls, which makes them impermeable to water and gases.

Function

The primary function of the cork cambium is to produce cork, a protective layer that insulates the plant from external physical damage and prevents water loss. This is particularly important for the survival of the plant in dry conditions. Additionally, the cork layer has antimicrobial properties, which protect the plant against pathogens. The activity of the cork cambium contributes to the thickening of the stem and root, a process known as secondary growth.

Ecological and Economic Importance

Cork cambium has significant ecological and economic importance. The cork cells it produces can be harvested from certain species, such as the Cork Oak (Quercus suber), without harming the tree. This harvested cork is used in a variety of products, including wine bottle stoppers, flooring, and insulation materials. The ability of cork cambium to regenerate after harvesting makes cork a sustainable natural resource.

See Also

• Meristem
• Secondary growth
• Vascular cambium
• Bark
• Suberin