Plant roots serve as the primary interface between the plant and the soil, encountering numerous challenges ranging from water balance to nutrient uptake. One of the central mechanisms enabling plants to thrive in diverse ecosystems is the building of apoplastic diffusion barriers. These barriers control the flow of solutes into and out of the roots, maintaining water and nutrient homeostasis. In this Review, we summarize recent advances in understanding the establishment, function and ecological significance of root apoplastic diffusion barriers. We highlight the plasticity of apoplastic diffusion barriers under various abiotic stresses such as drought, salinity and nutrient deficiency. We also propose new frontiers by discussing the current bottlenecks in the study of plant apoplastic diffusion barriers.

植物根系是植物和土壤之间的主要界面，面临着从水分平衡到养分吸收等众多挑战。使植物能够在不同的生态系统中茁壮成长的核心机制之一是建立质外体扩散屏障。这些屏障控制溶质流入和流出根部，维持水分和养分稳态。在这篇综述中，我们总结了了解根质外体扩散屏障的建立、功能和生态意义的最新进展。我们强调了质外体扩散屏障在各种非生物胁迫（如干旱、盐度和营养物质缺乏）下的可塑性。我们还通过讨论当前植物质外体扩散屏障研究的瓶颈提出了新的前沿。