生长素与植物根尖干细胞巢的维持

干细胞巢的维持与后代细胞的分化是多细胞高等生物个体发育的基础。生长素对植物茎尖和根尖分生组织的形态建成, 尤其是对位于植物这2个末端的分生组织中心的干细胞巢的活性维持起着至关重要的作用。该文综述了近几年在植物根尖干细胞发育领域的研究进展, 主要阐释了PLT蛋白途径、SCR-SHR蛋白途径以及环境因子多信号调控模块维持植物根尖分生组织中干细胞巢稳定的机制, 揭示了生长素可以通过就近合成、极性运输以及信号转导3种方式参与这些信号模块的调控, 从而维持生长素在根尖静止中心细胞附近干细胞巢的浓度梯度, 精确地平衡植物干细胞巢中细胞的增殖与分化。

Auxin and the Maintenance of Root Stem Cell Niches in Plants

The coordination between the maintenance of stem-cell niches and differentiation of their progeny sets the developmental basis of higher multiple-cellular organisms to ensure coherent organ growth. The plant hormone auxin plays important roles in the morphological establishment of shoot and root apical meristem mediated by the maintenance of shoot and root stem-cell niches. Here we review multiple signaling modules discovered in recent years, including the PLETHORA pathway, SCARECROW-SHORT ROOT pathway and environmental factors, for their mechanisms in maintaining root stem cell niches. Auxin participates in these mechanisms by regulating local synthesis, polar transport and signal transduction. By these means, auxin concentration gradient can be maintained accurately in stem-cell niches around the root apical quiescent center, for balancing the proliferation and differentiation of stem-cell niches.