A TCP domain transcription factor controls flower type specification along the radial axis of the Gerbera (Asteraceae) inflorescence
A TCP domain transcription factor controls flower type specification along the radial axis of the Gerbera (Asteraceae) inflorescence
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DOI：
10.1073/pnas.0801359105
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发表时间：
2008-07-01
影响因子：
11.1
通讯作者：
Elomaa, Paula
中科院分区：
文献类型：
--
作者：
Broholm, Suvi K.;Tahtiharju, Sari;Elomaa, Paula
植物发育过程中的几个关键过程都受到TCP转录因子的调控。类CYC TCP结构域蛋白已被证明在远亲植物谱系中控制花的对称性。非洲菊是被子植物中最大的分支之一，向日葵家族（菊科）的成员，是发育研究的有趣模型，因为其精致的花序包括具有专门结构和功能的不同类型的花。花型的形态分化包括花大小和对称性的逐渐变化，这些变化遵循密集花序的放射状组织。花瓣融合程度的差异进一步定义了非洲菊花型的独特形状。为了研究TCP转录因子在这个复杂的花序组织的规范过程中的作用，我们的特点是CYC样同系物GhCYC2非洲菊。GhCYC 2的表达沿花序径向轴沿着呈梯度变化。GhCYC2在边缘的、两侧对称的射线花中表达，但在最中心的花盘花中不表达，所述花盘花几乎径向对称并且具有显著较少的融合花瓣。GhCYC2的过表达导致盘状花获得类似于。雷花。表达模式和转基因表型表明，GhCYC2参与非洲菊花类型之间的分化，提供了第一个分子证据表明，CYC样TCP因子参与定义复杂的花序结构的菊科，一个主要的决定因素的家庭的进化成功。
Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-like (CYC-like) TCP domain proteins have been shown to control flower symmetry in distantly related plant lineages. Gerbera hybrida, a member of one of the largest clades of angiosperms, the sunflower family (Asteraceae), is an interesting model for developmental studies because its elaborate inflorescence comprises different types of flowers that have specialized structures and functions. The morphological differentiation of flower types involves gradual changes in flower size and symmetry that follow the radial organization of the densely packed inflorescence. Differences in the degree of petal fusion further define the distinct shapes of the Gerbera flower types. To study the role of TCP transcription factors during specification of this complex inflorescence organization, we characterized the CYC-like homolog GhCYC2 from Gerbera. The expression of GhCYC2 follows a gradient along the radial axis of the inflorescence. GhCYC2 is expressed in the marginal, bilaterally symmetrical ray flowers but not in the centermost disk flowers, which are nearly radially symmetrical and have significantly less fused petals. Overexpression of GhCYC2 causes disk flowers to obtain morphologies similar to. ray flowers. Both expression patterns and transgenic phenotypes suggest that GhCYC2 is involved in differentiation among Gerbera flower types, providing the first molecular evidence that CYC-like TCP factors take part in defining the complex inflorescence structure of the Asteraceae, a major determinant of the family's evolutionary success.