The endodermis is a layer of cells that prevents nutrients from leaving the plant structure and returning to the soil. It is commonly found in the root of the plant.
A plant's root is comprised of a number of layers, each with its own responsibility to promote the health of the plant. Overall, these layers work together to absorb water and nutrients, which are essential to keep the plant alive.
The endodermis offers protection from water saturation. Before water can penetrate the Casparian strip, it must first pass through the endodermis cells. From there, water can go through the Casparian strip, which allows the plant to absorb the water as needed.
In addition, the endodermis plays a role in helping the plant absorb nutrients. The structure of the cells helps to prevent nutrients from the xylem to diffuse back into the soil.