英国剑桥大学Yrjö Helariutta、美国纽约大学Kenneth D. Birnbaum和北卡罗来纳州立大学Rosangela Sozzani研究组合作的最新研究，通过对韧皮部发育细胞的逐层解剖发现组织成熟过程与细胞特化有关。相关论文发表在2021年12月24日出版的《科学》杂志上。
研究人员使用单细胞转录组学重建了拟南芥根从祖细胞开始到终末分化为原韧皮部的发育轨迹。PHLOEM早期DNA结合单指(PEAR)转录因子通过激活鸟苷三磷酸酶信号传导并诱导转录分化程序来介导谱系分叉。该程序最初被分生组织范围内的PLETHORA转录因子梯度抑制。只有消除dPLETHORA梯度才可以激活与早期和晚期分生组织调节器相互抑制的分化程序。因此，对于韧皮部的发育，广泛的成熟梯度与细胞类型特异性转录调节因子相结合以促进细胞分化。
据了解，在植物分生组织中，全组织成熟梯度与特有细胞网络相协调，构成了生长所需的各种发育阶段。
附：英文原文
Title: Cell-by-cell dissection of phloem development links a maturation gradient to cell specialization
Author: Pawel Roszak, Jung-ok Heo, Bernhard Blob, Koichi Toyokura, Yuki Sugiyama, Maria Angels de Luis Balaguer, Winnie W. Y. Lau, Fiona Hamey, Jacopo Cirrone, Ewelina Madej, Alida M. Bouatta, Xin Wang, Marjorie Guichard, Robertas Ursache, Hugo Tavares, Kevin Verstaen, Jos Wendrich, Charles W. Melnyk, Yoshihisa Oda, Dennis Shasha, Sebastian E. Ahnert, Yvan Saeys, Bert De Rybel, Renze Heidstra, Ben Scheres, Guido Grossmann, Ari Pekka Mhnen, Philipp Denninger, Berthold Gttgens, Rosangela Sozzani, Kenneth D. Birnbaum, Yrj Helariutta
Issue&Volume: 2021-12-24
Abstract: In the plant meristem, tissue-wide maturation gradients are coordinated with specialized cell networks to establish various developmental phases required for indeterminate growth. Here, we used single-cell transcriptomics to reconstruct the protophloem developmental trajectory from the birth of cell progenitors to terminal differentiation in the Arabidopsis thaliana root. PHLOEM EARLY DNA-BINDING-WITH-ONE-FINGER (PEAR) transcription factors mediate lineage bifurcation by activating guanosine triphosphatase signaling and prime a transcriptional differentiation program. This program is initially repressed by a meristem-wide gradient of PLETHORA transcription factors. Only the dissipation of PLETHORA gradient permits activation of the differentiation program that involves mutual inhibition of early versus late meristem regulators. Thus, for phloem development, broad maturation gradients interface with cell-type-specific transcriptional regulators to stage cellular differentiation.
DOI: aba5531
Source: https://www.science.org/doi/10.1126/science.aba5531