Integration of floral inductive signals in Arabidopsis
Integration of floral inductive signals in Arabidopsis
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DOI：
10.1038/35009125
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发表时间：
2000-04-20
期刊：
影响因子：
64.8
通讯作者：
Weigel, D
中科院分区：
文献类型：
--
作者：
Blázquez, MA;Weigel, D
拟南芥的开花受到在长日照中加速开花的日照依赖性途径和在不存在诱导条件下确保开花的日照非依赖性途径的调节（1-3）。这些途径在遗传上是可分离的，因为有些突变会延迟长而不是短的开花时间（4）。相反，阻断激素赤霉素合成的突变在短日照时会导致开花消失，但在长日照时仅产生轻微影响（5）。第三种途径，自主途径，可能通过调节其他两种途径起作用（3）。了解这些途径在哪里以及如何整合是理解为什么相似的环境或内源性线索可以在不同的植物中引起相反的开花反应的先决条件（6，7）。在拟南芥中，成花诱导最终导致花分生组织身份基因如LEAFY（8-13）的上调，表明成花诱导信号整合在LEAFY的上游。在这里，我们表明，赤霉素激活LEAFY启动子通过顺式元件是不同的那些是足够的日照反应，表明LEAFY启动子集成了环境和内源信号控制开花时间。
Flowering of Arabidopsis is regulated by a daylength-dependent pathway that accelerates flowering in long days and a daylength-independent pathway that ensures flowering in the absence of inductive conditions(1-3). These pathways are genetically separable, as there are mutations that delay flowering in long but not short days(4). Conversely, mutations that block synthesis of the hormone gibberellin abolish flowering in short days, but have on their own only a minor effect in long days(5). A third pathway, the autonomous pathway, probably acts by modulating the other two pathways(3). Understanding where and how these pathways are integrated is a prerequisite for understanding why similar environmental or endogenous cues can elicit opposite flowering responses in different plants(6,7). In Arabidopsis, floral induction leads ultimately to the upregulation of floral meristem-identity genes such as LEAFY(8-13), indicating that floral inductive signals are integrated upstream of LEAFY. Here we show that gibberellins activate the LEAFY promoter through cis elements that are different from those that are sufficient for the daylength response, demonstrating that the LEAFY promoter integrates environmental and endogenous signals controlling flowering time.