and Dietrich, Daniela and Bennett, Malcolm J. (2017) Plant biology: building barriers... in roots. Current Biology, 27 (5). R172-R174. 1879-0445

The Casparian strip is an important barrier regulating water and nutrient uptake into root tissues. New research reveals two pepide signals and their co-receptors play critical roles patterning and maintaining barrier integrity. Plant roots are required to explore highly heterogeneous soil environments to secure essential resources such as water and nutrients [1]. Roots have developed barrier-like structures to regulate the flow of these resources between the external soil environment and xylem tissue that transport them to the shoot These root barriers include the Casparian strip that forms a watertight structure in the endodermal layer and blocks the free passage of chemicals between cortex and xylem How such a precisely positioned barrier forms has recently attracted significant research interest. New papers published in Current Biology [3] and Science [4,5] provide novel molecular insights, reporting new components and an elegant patterning mechanism that controls Casparian strip formation and integrity.