parenkéma

Parenchyma is a fundamental type of plant tissue. It is characterized by living cells that are typically isodiametric, meaning they have roughly equal dimensions in all directions. These cells have thin primary cell walls and large central vacuoles. Parenchyma cells are found throughout the plant, forming the bulk of the mesophyll in leaves, the cortex and pith in stems and roots, and the flesh of fruits.

The functions of parenchyma are diverse and crucial for plant survival. Parenchyma cells are involved in photosynthesis, particularly in the mesophyll of leaves where they contain chloroplasts. They also serve as storage tissues, accumulating starch, oils, proteins, and water in various plant organs like roots, tubers, and seeds. Additionally, parenchyma plays a role in secretion, producing substances like nectar and latex. These cells are also essential for wound healing and regeneration, as they can divide and differentiate into other cell types when needed. The presence of intercellular spaces between parenchyma cells facilitates gas exchange within the plant. In some cases, parenchyma cells can also be involved in transport of water and nutrients.