Weir Irene, Lu Jianping, Cook Holly, Causier Barry, Schwarz-Sommer Zsuzsanna, Davies Brendan
Centre for Plant Sciences, University of Leeds, Leeds LS2 9JT, UK.
Development. 2004 Feb;131(4):915-22. doi: 10.1242/dev.00993.
Cupuliformis mutants are defective in shoot apical meristem formation, but cup plants overcome this early barrier to development to reach maturity. CUP encodes a NAC-domain transcription factor, homologous to the Petunia NAM and Arabidopsis CUC proteins. The phenotype of cup mutants differs from those of nam and cuc1 cuc2 in that dramatic organ fusion is observed throughout development. In addition to cotyledon and floral organ fusions, severe lateral organ fusion is found in leaves and inflorescences, and the apical meristem becomes highly fasciated. These features reveal a role for CUP in the establishment of all above ground organ boundaries. Consistent with this function, CUP is expressed at the boundaries of all lateral organs and meristems. It is not currently known how NAC-domain genes act to establish organ boundaries. Here, we show that CUP directly interacts with a TCP-domain transcription factor. Members of the TCP-domain family have previously been shown to regulate organ outgrowth. Our results suggest a model for the establishment of organ boundaries based on the localised expression of NAC-domain and TCP-domain factors.
杯状突变体在茎尖分生组织形成方面存在缺陷，但杯状植物克服了这一早期发育障碍并达到成熟。CUP编码一种NAC结构域转录因子，与矮牵牛NAM和拟南芥CUC蛋白同源。杯状突变体的表型与nam和cuc1 cuc2不同，在于在整个发育过程中观察到显著的器官融合。除了子叶和花器官融合外，在叶片和花序中还发现严重的侧生器官融合，并且顶端分生组织变得高度扁平。这些特征揭示了CUP在所有地上器官边界建立中的作用。与该功能一致，CUP在所有侧生器官和分生组织的边界处表达。目前尚不清楚NAC结构域基因如何作用于建立器官边界。在这里，我们表明CUP直接与一个TCP结构域转录因子相互作用。TCP结构域家族成员先前已被证明可调节器官生长。我们的结果提出了一个基于NAC结构域和TCP结构域因子局部表达建立器官边界的模型。
