Antagonistic regulation of flowering-time gene SOC1 by CONSTANS and FLC via separate promoter motifs
Antagonistic regulation of flowering-time gene SOC1 by CONSTANS and FLC via separate promoter motifs
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DOI：
10.1093/emboj/cdf432
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发表时间：
2002-08-15
期刊：
影响因子：
11.4
通讯作者：
Coupland, G
中科院分区：
文献类型：
--
作者：
Hepworth, SR;Valverde, F;Coupland, G
拟南芥的开花是由不同的遗传途径传递的内源和环境信号控制的。MADS盒开花时间基因SOC1由几种途径调节，并被提议协调对环境信号的响应。SOC1在长光周期中被CONSTANS（CO）直接激活，并被FLC抑制，FLC是春化（低温）途径的一个组成部分。我们发现，在过表达CO和FLC的转基因植物中，这些蛋白质调控开花时间拮抗和FLC块转录激活的SOC1 CO。一系列的SOC1：：GUS报告基因确定了一个351 bp的启动子序列，介导激活CO和镇压FLC。该序列中的CArG盒（MADS结构域蛋白结合元件）在体外被FLC特异性识别，并在体内被FLC介导抑制，表明FLC直接结合至SOC 1启动子。我们建议，CO被招募到一个单独的启动子元件的DNA结合因子和CO的激活受损时，FLC结合到一个相邻的CArG基序。
Flowering in Arabidopsis is controlled by endogenous and environmental signals relayed by distinct genetic pathways. The MADS-box flowering-time gene SOC1 is regulated by several pathways and is proposed to co-ordinate responses to environmental signals. SOC1 is directly activated by CONSTANS (CO) in long photoperiods and is repressed by FLC, a component of the vernalization (low-temperature) pathway. We show that in transgenic plants overexpressing CO and FLC, these proteins regulate flowering time antagonistically and FLC blocks transcriptional activation of SOC1 by CO. A series of SOC1::GUS reporter genes identified a 351 bp promoter sequence that mediates activation by CO and repression by FLC. A CArG box (MADS-domain protein binding element) within this sequence was recognized specifically by FLC in vitro and mediated repression by FLC in vivo, suggesting that FLC binds directly to the SOC1 promoter. We propose that CO is recruited to a separate promoter element by a DNA-binding factor and that activation by CO is impaired when FLC is bound to an adjacent CArG motif.