Integrating long-day flowering signals: a LEAFY binding site is essential for proper photoperiodic activation of APETALA1
Integrating long-day flowering signals: a LEAFY binding site is essential for proper photoperiodic activation of APETALA1
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DOI：
10.1111/j.1365-313x.2011.04660.x
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发表时间：
2011-09-01
期刊：
影响因子：
7.2
通讯作者：
Nilsson, Ove
中科院分区：
文献类型：
--
作者：
Benlloch, Reyes;Kim, Min Chul;Nilsson, Ove
拟南芥向开花的转变的特征在于新形成的花原基中APETALA 1（AP 1）转录的急剧和局部上调。花分生组织身份基因LEAFY（LFY）和涉及FLOWERSHIP LOCUS T（FT）和FD基因的光周期途径都有助于这种上调。这些途径被认为是独立的，但它们各自的贡献和相互作用的模式仍然难以捉摸。为了解决这些问题，我们研究了AP 1调控区。结合在体外和体内的方法，我们确定了这三个假定的LFY结合位点存在于AP 1启动子是必不可少的激活LFY。有趣的是，我们发现，这个网站也是重要的正确的光依赖性上调AP 1。相比之下，先前提出的推定FD结合位点似乎是不稳定的，不能结合FD，我们没有发现FD与AP 1启动子中其他位点结合的证据，这表明AP 1的FT/FD依赖性激活可能是间接的。总而言之，我们的数据提供了新的洞察FT和LFY途径之间的相互作用，在长日照条件下的AP 1转录上调。
The transition to flowering in Arabidopsis is characterized by the sharp and localized upregulation of APETALA1 (AP1) transcription in the newly formed floral primordia. Both the flower meristem-identity gene LEAFY (LFY) and the photoperiod pathway involving the FLOWERING LOCUS T (FT) and FD genes contribute to this upregulation. These pathways have been proposed to act independently but their respective contributions and mode of interaction have remained elusive. To address these questions, we studied the AP1 regulatory region. Combining in vitro and in vivo approaches, we identified which of the three putative LFY binding sites present in the AP1 promoter is essential for its activation by LFY. Interestingly, we found that this site is also important for the correct photoperiodic-dependent upregulation of AP1. In contrast, a previously proposed putative FD-binding site appears dispensable and unable to bind FD and we found no evidence for FD binding to other sites in the AP1 promoter, suggesting that the FT/FD-dependent activation of AP1 might be indirect. Altogether, our data give new insight into the interaction between the FT and LFY pathways in the upregulation of AP1 transcription under long-day conditions.