What is the term for the band of cells containing suberin that is impermeable to water in plant roots?

The term for the band of cells that contains suberin and is impermeable to water in plant roots is known as the Casparian strip. This structure is located in the endodermis of roots and plays a crucial role in regulating the flow of water and nutrients from the soil into the plant. The presence of suberin, a fatty substance, makes the Casparian strip hydrophobic, effectively preventing water and solutes from passing through the apoplast pathway—instead, they must pass through the symplast pathway, where selective uptake can occur. This allows the plant to control the absorption of minerals and prevents harmful substances in the soil from entering the vascular system.

The other terms provided do not correspond to well-established botanical structures or functions relevant to water impermeability in plant roots. Thus, the Casparian strip is the key feature that enables plants to regulate hydration and nutrient absorption efficiently.