Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Cell Rep. 2018 May 8;23(6):1879-1890. doi: 10.1016/j.celrep.2018.04.033.
Organogenesis in higher plants occurs in the shoot meristem, which contains pluripotent stem cells. Here, we show that two multiple C2 domain and transmembrane region proteins, FT INTERACTING PROTEIN 3 (FTIP3) and FTIP4, play an essential role in mediating proliferation and differentiation of shoot stem cells in Arabidopsis. FTIP3/4 prevent intracellular trafficking of a key regulator, SHOOTMERISTEMLESS (STM), to the plasma membrane in cells in the peripheral shoot meristem region. This facilitates STM recycling to the nucleus to maintain stem cells. Without FTIP3/4, STM localizes substantially to the plasma membrane, which promotes intercellular trafficking but compromises nuclear localization of STM. This accelerates stem cell differentiation, causing early termination of shoot apices and resulting in dwarf and bushy phenotypes. Our findings reveal a molecular framework that determines the fate of shoot stem cells and the resulting aboveground plant body.
高等植物的器官发生发生在茎分生组织中，其中包含多能干细胞。在这里，我们表明，两个多 C2 结构域和跨膜区域蛋白，FT INTERACTING PROTEIN 3（FTIP3）和 FTIP4，在介导拟南芥茎干细胞的增殖和分化中起重要作用。FTIP3/4 阻止关键调节因子 SHOOTMERISTEMLESS（STM）在周围茎分生组织区域的细胞内向质膜的细胞内运输。这有利于 STM 向核内循环以维持干细胞。没有 FTIP3/4，STM 主要定位于质膜，这促进了细胞间的运输，但损害了 STM 的核定位。这加速了干细胞分化，导致茎尖的早期终止，并导致矮小和丛生的表型。我们的发现揭示了一个决定茎干细胞命运和由此产生的地上植物体的分子框架。
