Department of Plant Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology Ikoma, Japan.
Front Plant Sci. 2014 Apr 30;5:165. doi: 10.3389/fpls.2014.00165. eCollection 2014.
Carpel margin meristems (CMMs), a pair of meristematic tissues present along the margins of two fused carpel primordia of Arabidopsis thaliana, are essential for the formation of ovules and the septum, two major internal structures of the gynoecium. Although a number of regulatory factors involved in shoot meristem activity are known to be required for the formation of these gynoecial structures, their direct roles in CMM development have yet to be addressed. Here we show that the CUP-SHAPED COTYLEDON genes CUC1 and CUC2, which are essential for shoot meristem initiation, are also required for formation and stable positioning of the CMMs. Early in CMM formation, CUC1 and CUC2 are also required for expression of the SHOOT MERISTEMLESS gene, a central regulator for stem cell maintenance in the shoot meristem. Moreover, plants carrying miR164-resistant forms of CUC1 and CUC2 resulted in extra CMM activity with altered positioning. Our results thus demonstrate that the two regulatory proteins controlling shoot meristem activity also play critical roles in elaboration of the female reproductive organ through the control of meristematic activity.
心皮边缘分生组织（Carpel Margin Meristems，CMMs），是一对存在于拟南芥两个融合心皮原基边缘的分生组织，对于胚珠和隔膜（雌蕊的两个主要内部结构）的形成是必不可少的。尽管已经知道许多参与茎分生组织活性的调节因子对于这些雌蕊结构的形成是必需的，但它们在 CMM 发育中的直接作用尚未得到解决。在这里，我们发现，对于茎分生组织起始至关重要的 CUP-SHAPED COTYLEDON 基因 CUC1 和 CUC2，也需要 CMM 的形成和稳定定位。在 CMM 形成的早期，CUC1 和 CUC2 也需要表达 SHOOT MERISTEMLESS 基因，该基因是茎分生组织中干细胞维持的中央调节剂。此外，携带 miR164 抗性形式的 CUC1 和 CUC2 的植物导致额外的 CMM 活性和改变的定位。因此，我们的研究结果表明，控制茎分生组织活性的两种调节蛋白，通过控制分生组织的活性，在雌性生殖器官的精细发育中也起着关键作用。
