Mesophloeum is a botanical term used to describe a specific tissue found in the stems and roots of certain plants. It is derived from the Greek words "mesos," meaning middle, and "phloios," meaning bark.
Mesophloeum refers to the region of the bark situated between the outermost layer, known as the outer bark or periderm, and the innermost layer, known as the inner bark or secondary phloem. It is located directly below the periderm and above the secondary phloem.
The mesophloeum generally consists of a layer of cells that facilitate important functions in the plant. Its primary role involves providing structural support and protection. The mesophloeum acts as a barrier against external threats, such as pathogens, mechanical damage, and excessive water loss.
Moreover, the tissue has the ability to transport nutrients, hormones, and other essential substances throughout the plant body. It contains specialized cells, such as sieve cells and companion cells, which form conducting tubes for the movement of sugars and other organic compounds. These cells create a network that allows for the efficient distribution of resources to various plant parts.
In some plant species, the mesophloeum may also contribute to the storage of carbohydrates or water, thereby aiding in the plant's resilience during periods of stress or unfavorable conditions.
Overall, the mesophloeum plays a crucial role in supporting, protecting, and facilitating the vital physiological processes of plants.
