山东农业大学张宪省团队取得一项新突破。他们开发出植物再生过程中单个体细胞进入全能性状态的时间分辨重编程。该项研究成果发表在2025年9月16日出版的《细胞》上。
该团队发现，在拟南芥子叶中，LEAFY COTYLEDON2 (LEC2) 重编程表达SPEECHLESS（SPCH）的分生组织母细胞（MMCs），使其远离气孔谱系的进展，推动其转化为全能体细胞胚胎建立细胞（sefc）。通过实时成像、单核RNA测序（snRNA-seq）和空间激光捕获显微解剖结合RNA测序（LCM-RNA-seq），研究团队发现了一个谱系分叉点，MMC衍生物要么参与保护细胞，要么转变为保护母细胞(GMC)-生长素中间体，一种生长素富集状态，能够实现转录重编程和胚胎基因激活。
LEC2和SPCH协同激活拟南芥1 （TAA1）和YUCCA4 （YUC4）的色氨酸氨基转移酶，建立了SEFC规范所必需的局部生长素生物合成回路。遗传和启动子分析证实MMCs是体细胞胚胎的起源，TAA1/YUC介导的生长素的产生对于全能性和胚胎发生是必不可少的。这些发现定义了生长素驱动的、转录调控的将气孔祖细胞与体细胞胚胎发生联系起来的轨迹，揭示了促进植物再生可塑性机制理解的直接途径。
据介绍，全能性使单个细胞能够再生生物体，但分化的体细胞如何重新获得这种潜力尚不清楚。
附：英文原文
Title: Time-resolved reprogramming of single somatic cells into totipotent states during plant regeneration
Author: Li Ping Tang, Li Ming Zhai, Jiming Li, Yue Gao, Qiu Li Ma, Rui Li, Qing Fei Liu, Wen Jie Zhang, Wang Jinsong Yao, Bangbang Mu, Chao Qin, Xin Tian, Rahul Shaw, Keke Xia, Jian Xu, Ying Hua Su, Xian Sheng Zhang
Issue&Volume: 2025-09-16
Abstract: Totipotency enables single cells to regenerate an organism, yet how differentiated somatic cells reacquire this potential remains unclear. Here, we show that LEAFY COTYLEDON2 (LEC2) reprograms SPEECHLESS (SPCH)-expressing meristemoid mother cells (MMCs) away from stomatal-lineage progression, driving their conversion into totipotent somatic embryo founder cells (SEFCs) in Arabidopsis cotyledons. Using time-course live imaging, single-nucleus RNA sequencing (snRNA-seq), and spatial laser capture microdissection combined with RNA sequencing (LCM-RNA-seq), we uncover a lineage bifurcation point where MMC derivatives either commit to guard cells or transition into a guard mother cell (GMC)-auxin intermediate, an auxin-enriched state that enables transcriptional reprogramming and embryonic gene activation. LEC2 and SPCH cooperatively activate TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and YUCCA4 (YUC4), establishing a local auxin biosynthesis circuit essential for SEFC specification. Genetic and promoter analyses confirm MMCs as the origin of somatic embryos, with TAA1/YUC-mediated auxin production indispensable for totipotency and embryogenesis. These findings define an auxin-driven, transcriptionally regulated trajectory linking stomatal progenitors to somatic embryogenesis, revealing a direct route that advances mechanistic understanding of plant regenerative plasticity.
DOI: 10.1016/j.cell.2025.08.031
Source: https://www.cell.com/cell/abstract/S0092-8674(25)01020-7