Aida M, Ishida T, Tasaka M
Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan.
Development. 1999 Apr;126(8):1563-70. doi: 10.1242/dev.126.8.1563.
The shoot apical meristem and cotyledons of higher plants are established during embryogenesis in the apex. Redundant CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 as well as SHOOT MERISTEMLESS (STM) of Arabidopsis are required for shoot apical meristem formation and cotyledon separation. To elucidate how the apical region of the embryo is established, we investigated genetic interactions among CUC1, CUC2 and STM, as well as the expression patterns of CUC2 and STM mRNA. Expression of these genes marked the incipient shoot apical meristem as well as the boundaries of cotyledon primordia, consistent with their roles for shoot apical meristem formation and cotyledon separation. Genetic and expression analyses indicate that CUC1 and CUC2 are redundantly required for expression of STM to form the shoot apical meristem, and that STM is required for proper spatial expression of CUC2 to separate cotyledons. A model for pattern formation in the apical region of the Arabidopsis embryo is presented.
高等植物的茎尖分生组织和子叶是在胚胎发育过程中于顶端形成的。拟南芥中冗余的杯状子叶1（CUC1）和CUC2以及无茎尖分生组织（STM）对于茎尖分生组织的形成和子叶分离是必需的。为了阐明胚胎顶端区域是如何形成的，我们研究了CUC1、CUC2和STM之间的遗传相互作用，以及CUC2和STM mRNA的表达模式。这些基因的表达标记了初期的茎尖分生组织以及子叶原基的边界，这与其在茎尖分生组织形成和子叶分离中的作用一致。遗传和表达分析表明，CUC1和CUC2对于STM的表达以形成茎尖分生组织是冗余必需的，并且STM对于CUC2的正确空间表达以分离子叶是必需的。本文提出了拟南芥胚胎顶端区域模式形成的模型。
