Kraska Leonie, Melia Josep Mercadal, Nakano Ryohei Thomas, Molina David, Formosa-Jordan Pau, Ragni Laura, Andersen Tonni Grube
Max Planck Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, 50829 Cologne, Germany.
ZMBP, Center for Plant Molecular Biology, University of Tübingen, Tübingen, Germany; University of Freiburg, Institute of Biology II, Schänzlerstr 1, 79104 Freiburg, Germany.
Cell Rep. 2025 Jun 24;44(6):115794. doi: 10.1016/j.celrep.2025.115794. Epub 2025 Jun 6.
Roots are composed of concentric layers that surround the vasculature of plants. Of these, the endodermis stands out, as it contains barriers that facilitate selective uptake. In mature root regions, endodermal cells become coated with suberin, a hydrophobic polymer that seals off the inner root parts. Intriguingly, individual endodermal cells, adjacent to the water-conducting xylem, remain unsuberized. These cells are termed "passage cells," based on the assumption that they can facilitate vasculature access in an otherwise sealed-off area. The existence of passage cells suggests that distinct identities and cell files exist within the endodermis that may have overlooked importance. Here, we investigate this in the model plant Arabidopsis thaliana. Our work identifies a genetic regulator of cell-file-specific suberization and passage cell differentiation connected to the xylem. This provides spatiotemporal insights into the mechanism(s) underlying suberization, establishing a framework for the radial organization of the endodermis and highlighting the putative function(s) of passage cells.
根由围绕植物维管系统的同心层组成。其中，内皮层尤为突出，因为它含有促进选择性吸收的屏障。在成熟的根区域，内皮层细胞会被栓质覆盖，栓质是一种疏水性聚合物，可封闭根的内部部分。有趣的是，与导水木质部相邻的单个内皮层细胞仍未栓质化。基于它们能够在原本封闭的区域促进维管系统连通的假设，这些细胞被称为“通道细胞”。通道细胞的存在表明内皮层中存在不同的细胞身份和细胞列，而这些可能被忽视了重要性。在这里，我们在模式植物拟南芥中对此进行研究。我们的工作确定了一个与木质部相关的、调控细胞列特异性栓质化和通道细胞分化的遗传因子。这为栓质化的潜在机制提供了时空见解，建立了内皮层径向组织的框架，并突出了通道细胞的假定功能。
