SummaryPlant roots forage the soil for nutrients and transport them upwards to the aerial parts. Nutrients entering the plant are transported through the concentric layers of epidermis, cortex and endodermis before reaching the central vasculature. The endodermis is the innermost cortical cell layer that surrounds the vasculature. The endodermis forms barriers, the Casparian strips and suberin lamellae, which have been assumed to play a major role in controlling nutrient acquisition. However, the molecular network controlling its differentiation has started to be investigated only recently, giving an unprecedented opportunity to address the role of these barriers in plant nutrition. This insight aims to present recent advances regarding endodermis differentiation, its function as a barrier for nutrients and its developmental plasticity, all pointing to a pivotal role of the endodermis as a checkpoint for nutrients. Contents Summary 1604 I. Introduction 1604 II. Endodermal differentiation 1604 III. The endodermis as a barrier 1605 IV. Endodermal plasticity to nutrients 1608 V. Conclusions 1609 Acknowledgements 1609 References 1609