Roots possess complex anatomical structures characterised by suberised apoplastic barriers that are deposited in localised cell wall layers. Barley roots lack an exodermis, but form an endodermis that accounts for the majority of the roots’ total suberin content.
Ranathunge et al. show that the basal zone with greater suberin is shown to have lower water permeability than the apical zone in Hordeum vulgare. A comparison of root and cell water permeabilities suggests a primary cell-to-cell water and nutrient transport system in barley roots in addition to flow via apoplastic pathways. Roots exhibited different permeabilities according to the different solutes used.
Ranathunge, K., Kim, Y. X., Wassmann, F., Kreszies, T., Zeisler, V., & Schreiber, L. (2017). The composite water and solute transport of barley (Hordeum vulgare) roots: effect of suberized barriers . Annals of Botany, mcw252. https://doi.org/10.1093/aob/mcw252