Department of Plant Molecular Biology, DBMV, UNIL-Sorge, University of Lausanne, 1015, Lausanne, Switzerland.
Electron Microscopy Facility, University of Lausanne, 1015, Lausanne, Switzerland.
Nat Commun. 2022 Mar 18;13(1):1489. doi: 10.1038/s41467-022-29110-0.
Suberin is a fundamental plant biopolymer, found in protective tissues, such as seed coats, exodermis and endodermis of roots. Suberin is deposited in most suberizing cells in the form of lamellae just outside of the plasma membrane, below the primary cell wall. How monomeric suberin precursors, thought to be synthesized at the endoplasmic reticulum, are transported outside of the cell, for polymerization into suberin lamellae has remained obscure. Using electron-microscopy, we observed large numbers of extracellular vesiculo-tubular structures (EVs) to accumulate specifically in suberizing cells, in both chemically and cryo-fixed samples. EV presence correlates perfectly with root suberization and we could block suberin deposition and vesicle accumulation by affecting early, as well as late steps in the secretory pathway. Whereas many previous reports have described EVs in the context of biotic interactions, our results suggest a developmental role for extracellular vesicles in the formation of a major cell wall polymer.
化感物质是一种基本的植物生物聚合物，存在于保护组织中，如种皮、根的外皮层和内皮层。化感物质以质膜外、初生细胞壁下的板层形式沉积在大多数化感细胞中。化感物质前体单体，被认为在内质网上合成，如何被运出细胞，用于聚合形成化感物质板层，这一点仍然不清楚。使用电子显微镜，我们观察到大量的细胞外囊泡管状结构（EVs）在化学和冷冻固定的样本中特异性地在化感细胞中积累。EV 的存在与根的化感作用完全相关，我们可以通过影响分泌途径的早期和晚期步骤来阻止化感物质的沉积和囊泡的积累。虽然许多先前的报道都描述了生物相互作用背景下的 EVs，但我们的结果表明，细胞外囊泡在形成主要细胞壁聚合物的过程中具有发育作用。
