Song Sang-Kee, Hofhuis Hugo, Lee Myeong Min, Clark Steven E
Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA.
Dev Cell. 2008 Jul;15(1):98-109. doi: 10.1016/j.devcel.2008.05.008.
Arabidopsis development proceeds from three stem cell populations located at the shoot, flower, and root meristems. The relationship between the highly related shoot and flower stem cells and the very divergent root stem cells has been unclear. We show that the related phosphatases POL and PLL1 are required for all three stem cell populations. pol pll1 mutant embryos lack key asymmetric divisions that give rise to the root stem cell organizer and the central vascular axis. Instead, these cells divide in a superficially symmetric fashion in pol pll1 embryos, leading to a loss of embryonic and postembryonic root stem cells and vascular specification. We present data that show that POL/PLL1 drive root stem cell specification by promoting expression of the WUS homolog WOX5. We propose that POL and PLL1 are required for the proper divisions of shoot, flower, and root stem cell organizers, WUS/WOX5 gene expression, and stem cell maintenance.
拟南芥的发育源于位于茎尖、花和根分生组织的三个干细胞群。高度相关的茎尖和花干细胞与差异很大的根干细胞之间的关系一直不清楚。我们发现相关的磷酸酶POL和PLL1是所有三个干细胞群所必需的。pol pll1突变体胚胎缺乏产生根干细胞组织中心和中央维管轴的关键不对称分裂。相反,这些细胞在pol pll1胚胎中以表面对称的方式分裂,导致胚胎和胚后根干细胞及维管特化的丧失。我们提供的数据表明,POL/PLL1通过促进WUS同源基因WOX5的表达来驱动根干细胞特化。我们提出,POL和PLL1是茎尖、花和根干细胞组织中心正常分裂、WUS/WOX5基因表达以及干细胞维持所必需的。