Vascular Cambium vs Cork Cambium
Difference between vascular cambium and cork cambium is a topic related to dicotyledonous plants. Vascular Cambium and Cork Cambium are two lateral meristems (undifferentiated cells) that are responsible for the secondary growth of the plant. Lateral meristems produce tissues that increase the diameter/girth of the plant. Cork cambium primarily produces cork while vascular cambium produces secondary xylem and secondary phloem of the plant.
What is Cork Cambium ( Phellogen)?
Dedifferentiated parenchyma cells produce Cork cambium. It lies in the outer part of the cortex (fig.1). It produces cork cells (phellem) to the exterior and replace the epidermis. It also produces phelloderm to the interior. As cork cells mature their cell walls secrete a waxy substance called suberin. Cells become dead when suberin is deposited in the cell walls. For this reason, the cork tissue protects plant stem or root from water loss, physical damage, and act as a barrier to pathogens. The cork cambium, cork, and phelloderm collectively known as the periderm. In the periderm, there are small, raised areas called lenticels. These areas consist of more spaces between cork cells, which enable gas exchange between inner live cells of woody stem or root with the outside air.
Figure 1 – Locations of cork cambium and vascular cambium of a typical woody stem
What is Vascular Cambium?
Vascular cambium is a cylinder of cells with one cell layer thickness. It adds secondary xylem to the interior and secondary phloem to the exterior and parenchyma cells to extend existing rays or to form new rays (fig.1). In woody stems, it is located outside the pith and primary xylem and to the inside of the cortex and primary phloem. In woody roots, it is located outside to the primary xylem and inside to the primary phloem. Cambium located in between primary xylem and primary phloem is called intrafasicular cambium. When secondary growth starts, single cell layer of medullary rays also turns into cambium cells known as interfasicular cambium. Both these intrafasicular and interfasicular cambia collectively known as the vascular cambium. Vascular rays store carbohydrates, support in wound repairing and also it helps to transport water and nutrients between secondary xylem and secondary phloem.
Vascular cambium can be found in dicotyledons
What is the difference between Vascular Cambium and Cork Cambium?
There are some similarities and differences between Vascular Cambium and Cork Cambium.
• Cork cambium and vascular cambium both are responsible for the secondary growth of the plants. Therefore, these are found only in dicotyledonous plants.
• Cork cambium and vascular cambium arise from the lateral meristematic tissue.
• Both cambia increase the girth to stems and roots.
• Both comprises of a single cell layer that adds new cells to the in terior and exterior of the plant body.
• Cork cambium is secondary in origin while vascualar cambium has both primary origin and secondary origin (intrafasicular cambium of the vascular cambium is primary in origin and interfasicular cambium is secondary in origin)
• Cork cambium is located outer part of the cortex while vascular cambium is located basically in-between primary xylem and primary phloem.
• Cork cambium produces cells to its exterior while vascular cambium produces secondary phloem to its exterior.
• Cork cambium produces phelloderm to its interior, but vascular cambium produces secondary xylem to its interior.
• Cork cambium produces lenticels that allow gas exchange between wood and outside air, while vascular rays produced by the vascularcambium allows water and nutrient transformation between secondary xylem and secondary phloem.
• New cork cambia are continuously produced when stem or root expansion splits original periderm (removal of periderm from plant removes the vascular cambium also). However, several vascular cambiaare not produced with the time in the plant.
In conclusion, both vascular cambium and cork cambium can be considered as meristematic tissue s that produce new cells that increase the girth, protection and allow efficient gas, nutrient and water movements in the secondary plant body.
Images Courtesy:
- Cork cambium via The Department of Biodiversity & Conservation Biology
- Vascular cambium by Rickjpelleg (CC BY-SA 2.5)
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