Palisade cell



Palisade cell, or palisade mesophyll cell are plant cells located inside the mesophyll of most green leaves. They are vertically elongated and are stacked side by side, in contrast to the irregular and loosely arranged spongy mesophyll cells beneath them. Palisade cells are responsible for carrying out the majority of the photosynthesis in a leaf.

Palisade cells occur in dicotyledonous plants, and also in the net-veined Monocots: the Araceae and Dioscoreaceae.

Structure
Palisade cells are located beneath the upper epidermis and cuticle but above the spongy mesophyll cells.

Palisade cells contain a high concentration of chloroplasts, particularly in the upper portion of the cell, making them the primary site of photosynthesis in the leaves of plants that contain them. Their vacuole also aids in this function: it is large and central, pushing the chloroplasts to the edge of the cell, maximising the absorption of light. For a faster intake of the carbon dioxide needed for this photosynthesis, palisade cells often have specialized structures such as ridges or invaginations on their cell walls, which increase the surface area available for gas exchange.