1] Institute of Plant and Microbial Biology, Academia Sinica, 128 Section 2 Academia Road, Nankang, Taipei 11529, Taiwan [2] Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, Cologne 50829, Germany [3] Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten-Strasse 13, Bonn 53115, Germany [4] Japan Science and Technology Agency, PRESTO, 4-8-1 Honcho, Kawaguchi, Saitama 332-0012, Japan.
Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, Cologne 50829, Germany.
Nat Commun. 2014 Apr 4;5:3553. doi: 10.1038/ncomms4553.
Arabidopsis FT protein is a component of florigen, which transmits photoperiodic flowering signals from leaf companion cells to the shoot apex. Here, we show that FT specifically binds phosphatidylcholine (PC) in vitro. A transgenic approach to increase PC levels in vivo in the shoot meristem accelerates flowering whereas reduced PC levels delay flowering, demonstrating that PC levels are correlated with flowering time. The early flowering is related to FT activity, because expression of FT-effector genes is increased in these plants. Simultaneous increase of FT and PC in the shoot apical meristem further stimulates flowering, whereas a loss of FT function leads to an attenuation of the effect of increased PC. Specific molecular species of PC oscillate diurnally, and night-dominant species are not the preferred ligands of FT. Elevating night-dominant species during the day delays flowering. We suggest that FT binds to diurnally changing molecular species of PC to promote flowering.
拟南芥 FT 蛋白是成花素的一个组成部分，它将光周期开花信号从叶伴胞传递到茎尖。在这里，我们表明 FT 蛋白在体外特异性结合磷脂酰胆碱（PC）。通过转基因方法在体内增加茎分生组织中的 PC 水平会加速开花，而降低 PC 水平会延迟开花，这表明 PC 水平与开花时间相关。早期开花与 FT 活性有关，因为在这些植物中 FT 效应基因的表达增加了。同时增加茎尖分生组织中的 FT 和 PC 进一步刺激开花，而 FT 功能的丧失会导致 PC 增加效应的减弱。PC 的特定分子种类呈昼夜节律性波动，而夜间优势的物种不是 FT 的首选配体。在白天升高夜间优势的物种会延迟开花。我们认为 FT 结合昼夜变化的 PC 分子种类来促进开花。
