Explanation
Casparian strips contain "Suberin". Casparian strips are a layer of specialized, waterproof material found in the cell walls of the endodermis, a layer of cells that surrounds the vascular tissue in plant roots. They are composed of suberin, a complex mixture of fatty acids and phenolic compounds, and their function is to regulate the movement of water and solutes from the soil into the plant.
The suberin in the Casparian strips prevents water and solutes from passing through the cell walls of the endodermis, forcing them to pass through the selectively permeable cell membranes of the endodermal cells. This allows the plant to control the uptake of nutrients and water from the soil, preventing the loss of water and minerals through the roots. Cutin and wax are other types of waterproof materials found in plant tissues, while pectin is a type of cell wall polysaccharide that provides structural support.
