Integration of flowering signals in winter-annual Arabidopsis
Integration of flowering signals in winter-annual Arabidopsis
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DOI：
10.1104/pp.104.052811
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发表时间：
2005-01-01
期刊：
影响因子：
7.4
通讯作者：
Amasino, RM
中科院分区：
文献类型：
--
作者：
Michaels, SD;Himelblau, E;Amasino, RM
光周期是影响拟南芥快速循环材料开花时间的主要环境因子。冬季一年生拟南芥，相比之下，有一个光周期和春化要求快速开花。在冬季一年生植物中，高水平的成花抑制剂FLC（FLOWERLOCUS C）在春化之前抑制开花。FLC起延迟开花的作用，部分是通过抑制成花启动子SOC 1的表达（CONSTANS1过表达的提供者）。春化作用导致FLC的永久性表观遗传抑制。要调查如何冬季一年加入整合信号的光周期和春化途径，我们已经研究了激活标记的等位基因的FT和FT同系物，TSF（双姐妹FT），在冬季一年的背景。FT或TSF的激活强烈抑制FLC介导的晚开花表型的冬季一年生植物，然而，FT和TSF过表达不影响FLC mRNA水平。相反，FT和TSF通过激活SOC1表达绕过FLC对开花的阻断。我们还发现FLC作为FT表达的剂量依赖性抑制剂。因此，从光周期和春化途径的开花信号的整合发生，至少部分地，通过FT，TSF和SOC 1的调节。
Photoperiod is the primary environmental factor affecting flowering time in rapid-cycling accessions of Arabidopsis (Arabidopsis thaliana). Winter-annual Arabidopsis, in contrast, have both a photoperiod and a vernalization requirement for rapid flowering. In winter annuals, high levels of the floral inhibitor FLC (FLOWERING LOCUS C) suppress flowering prior to vernalization. FLC acts to delay flowering, in part, by suppressing expression of the floral promoter SOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1). Vernalization leads to a permanent epigenetic suppression of FLC. To investigate how winter-annual accessions integrate signals from the photoperiod and vernalization pathways, we have examined activation-tagged alleles of FT and the FT homolog, TSF (TWIN SISTER OF FT), in a winter-annual background. Activation of FT or TSF strongly suppresses the FLC-mediated late-flowering phenotype of winter annuals; however, FT and TSF overexpression does not affect FLC mRNA levels. Rather, FT and TSF bypass the block to flowering created by FLC by activating SOC1 expression. We have also found that FLC acts as a dosage-dependent inhibitor of FT expression. Thus, the integration of flowering signals from the photoperiod and vernalization pathways occurs, at least in part, through the regulation of FT, TSF, and SOC1.