What is a casparian strip made of?

The endodermis of the plant root system possess a woody and corky band, called the casparian strip, around all the cell walls except those facing toward the axis and stem.

The endodermis with its casparian strips may function in regulating the flow of water and nutrients.

Their presence generates a barrier that is thought to be crucial for selective nutrient uptake, exclusion of pathogens, and many other processes.

The chemical nature of Casparian strips has remained a matter of debate, but recent studies have indicated that they are made of lignin and not suberin.