研究人员表明，由TRACHEARY ELEMENT DIFFERENTIATION INHIBITORY FACTOR（TDIF）配体激活的PHLOEM INTERCALATED WITH XYLEM（PXY）受体促进CAMBIUM-EXPRESSED AINTEGUMENTA-LIKE（CAIL）转录因子的表达，从而在拟南芥根中定义形成层干细胞特性。
通过隔离来源于韧皮部的TDIF，木质部表达的PXY限制了TDIF信号前沿，从而在仅有的狭窄区域内激活CAIL表达和干细胞特性。该发现揭示了来自两侧细胞的信号如何确保双面干细胞层的稳健且动态可调的定位。
研究人员表示，木材是陆地生物质的最大储库。由木质部组成的木材来源于维管形成层的一侧，这是一种双面干细胞区域，同时在另一侧生成韧皮部。目前尚不清楚哪些分子因子赋予形成层干细胞特性。
附：英文原文
Title: Identification of cambium stem cell factors and their positioning mechanism
Author: Gugan Eswaran, Xixi Zhang, Jacob Pieter Rutten, Jingyi Han, Hiroyuki Iida, Jennifer López Ortiz, Riikka Mkil, Brecht Wybouw, Benjamin Planterose Jiménez, Leo Vainio, Alexis Porcher, Marina Leal Gavarron, Jing Zhang, Tiina Blomster, Xin Wang, David Dolan, Ondej Smetana, Siobhán M. Brady, Melis Kucukoglu Topcu, Kirsten ten Tusscher, J. Peter Etchells, Ari Pekka Mhnen
Issue&Volume: 2024-11-08
Abstract: Wood constitutes the largest reservoir of terrestrial biomass. Composed of xylem, it arises from one side of the vascular cambium, a bifacial stem cell niche that also produces phloem on the opposing side. It is currently unknown which molecular factors endow cambium stem cell identity. Here we show that TRACHEARY ELEMENT DIFFERENTIATION INHIBITORY FACTOR (TDIF) ligand–activated PHLOEM INTERCALATED WITH XYLEM (PXY) receptors promote the expression of CAMBIUM-EXPRESSED AINTEGUMENTA-LIKE (CAIL) transcription factors to define cambium stem cell identity in the Arabidopsis root. By sequestrating the phloem-originated TDIF, xylem-expressed PXY confines the TDIF signaling front, resulting in the activation of CAIL expression and stem cell identity in only a narrow domain. Our findings show how signals emanating from cells on opposing sides ensure robust yet dynamically adjustable positioning of a bifacial stem cell layer.
DOI: adj8752
Source: https://www.science.org/doi/10.1126/science.adj8752