FLOWERING LOCUS C encodes a novel MADS domain protein that acts as a repressor of flowering
FLOWERING LOCUS C encodes a novel MADS domain protein that acts as a repressor of flowering
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DOI：
10.1105/tpc.11.5.949
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发表时间：
1999-05-01
期刊：
影响因子：
11.6
通讯作者：
Amasino, RM
中科院分区：
文献类型：
--
作者：
Michaels, SD;Amasino, RM
冬季-一年生态型拟南芥的开花相对较晚，除非这些生态型的开花是通过暴露在寒冷(春化)促进的。这种春化抑制的晚花表型是由于在FRIGIDA(FRi)和开花基因C(FLC)两个座位上存在显性的晚花等位基因所致。在这项研究中，我们报道了FLC零突变导致早花，证明了活跃的FLC等位基因的作用是抑制开花。通过定位克隆获得FLC，发现其编码一个新的MADS结构域蛋白。FRI对FLC基因的表达有正调控作用，而LUMINIDENDENS对FLC基因的表达有负调节作用。FLC也受到春化的负调控。异源启动子的FLC过表达足以在缺乏活性FRI等位基因的情况下延迟开花。我们认为，FLC活性水平通过一种类似变阻器的机制来控制拟南芥的开花时间，并且FLC表达的调节是春化反应的一个组成部分。
Winter-annual ecotypes of Arabidopsis are relatively late flowering, unless the flowering of these ecotypes is promoted by exposure to cold (vernalization). This vernalization-suppressible, late-flowering phenotype results from the presence of dominant, late-flowering alleles at two loci, FRIGIDA (FRI) and FLOWERING LOCUS C (FLC). In this study, we report that flc null mutations result in early flowering, demonstrating that the role of active FLC alleles is to repress flowering. FLC was isolated by positional cloning and found to encode a novel MADS domain protein. The levels of FLC mRNA are regulated positively by FRI and negatively by LUMINIDEPENDENS. FLC is also negatively regulated by vernalization. Overexpression of FLC from a heterologous promoter is sufficient to delay flowering in the absence of an active FRI allele. We propose that the level of FLC activity acts through a rheostat-like mechanism to control flowering time in Arabidopsis and that modulation of FLC expression is a component of the vernalization response.