Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
School of Food Industrial Sciences, Miyagi University, Sendai 982-0215, Japan.
Sci Adv. 2024 Aug 30;10(35):eadq6082. doi: 10.1126/sciadv.adq6082. Epub 2024 Aug 28.
The shoot apical meristem (SAM) contains pluripotent stem cells that produce all the aerial parts of the plant. Stem cells undergo asymmetric cell divisions to self-renew and to produce differentiating cells. Our research focused on unraveling the mechanisms governing the specification of these two distinct cell fates following the stem cell division. For this purpose, we used the model organism , which features a singular pluripotent stem cell known as the gametophore apical cell. We show that the activity of cytokinins, critical stem cell regulators, is restricted to the gametophore apical cell due to the specific localization of PpLOG, the enzyme responsible for cytokinin activation. In turn, PpTAW, which promotes differentiating cell identity of the merophyte, is excluded from the gametophore apical cell by the action of cytokinins. We propose a cytokinin-based model for the establishment of asymmetry in the pluripotent stem cell division.
茎尖分生组织（SAM）包含多能干细胞，这些干细胞产生植物的所有气生部分。干细胞通过不对称细胞分裂来自我更新和产生分化细胞。我们的研究集中于揭示在干细胞分裂后控制这两种不同细胞命运特化的机制。为此，我们使用了模式生物 ，其特征是具有一个单一的多能干细胞，称为配子体顶端细胞。我们表明，细胞分裂素的活性，这是关键的干细胞调节因子，由于负责细胞分裂素激活的 PpLOG 酶的特异性定位，限制在配子体顶端细胞中。反过来，促进胚胎细胞身份分化的 PpTAW 被细胞分裂素排除在配子体顶端细胞之外。我们提出了一个基于细胞分裂素的模型，用于在多能干细胞分裂中建立不对称性。
