拟南芥FT调控开花的分子机制研究

The Arabidopsis Flowering Locus T gene is widely accepted as an essential component of the systemically mobile florigen. However, how the FT protein regulates florigen signalingis still need further study. In this project, we intend to screen other unknown, new proteins which interact with FT protein, and involved in florigen singnaling. First we used Yeast Two-Hybrid system to obtain a serial of FT Binding Protein (FTBP), and we will use other straights such as Pull-Down and Coimmunoprecipitation to prove the interaction of FT and FTBP. Then we will test the phenotype of over-expression and T-DNA inseration plants of FTBP, and the expression of genes involved in the florigen singling pathway, in order to obtain the controlling mechanism of FT in florigen signaling. From the study that we have done, we already have obtained some FTBP, and proved that 3 of them are involved in florigen singling. The study of these proteins will help us to understand the molecular mechanism of FT in florigen signaling. Outcomes of this project will not only shed new light on the FT signaling in flowering induction, but also provide novel theoretical bases in order to develop innovative strategies to control the process of flowering in agricultural and horticultural crops for desired traits.

FT是植物开花起始的重要开关，它整合了很多开花信号途径。本项目拟通过筛选FT的互作蛋白FTBP（FT Binding Protein），来进一步研究FT调控植物开花的分子机制。本项目首先通过筛选拟南芥酵母库得到一系列FTBP，利用免疫共沉淀等方法进一步验证FT和FTBP的互作，观察FTBP过表达和T-DNA插入纯合株系的开花表型，分析FTBP的亚细胞定位和时空表达模式。随后发展FTBP过表达、T-DNA插入株系与FT过表达、T-DNA插入株系的杂交植株，观察纯合杂交植株的开花表型，检测开花途径基因的表达，从而阐明FTBP和FT互作后调控植物开花的分子机制。我们前期已经筛选得到了和FT互作的FTBP，并且发现其中3个未报道的FTBP参与了植物开花过程。对于它们的进一步深入研究将有助于我们解析FT调控植物开花的分子机制，还可在一定程度上控制植物的花发育进程，这具有重大的研究意义和经济应用前景。

开花是高等植物从营养生长到生殖生长的重要转折点，对生殖生长的成功至关重要。FT是植物开花起始的重要开关，它整合了很多开花信号途径。但是目前对FT调控植物开花的机制研究及相关互作蛋白的发掘仍未深入。本项目围绕筛选和FT蛋白互作的调控植物开花的相关蛋白FTBP（FT Binding Protein），以及解析筛选到的FTBP蛋白调控植物开花的分子机制展开研究。首先，我们通过酵母双杂交的方法筛选得到和拟南芥FT蛋白互作的候选基因1603个，随后从中挑选部分候选基因做进一步研究，我们发现其中3个候选基因FTBP1、FTBP4、FTBP6和FT蛋白互作，且它们的突变体ftbp1晚花，ftbp4和ftbp6早花。随后我们对FTBP1调控植物开花的机制做进一步研究。研究结果表明，FTBP1参与光周期途径，并且证明了FTBP1通过调控CO基因的表达，从而调控植物开花。在此基础上，更进一步证明，FTBP1蛋白和其它CO上游调控因子一样，蛋白稳定性受光调控，且降解是通过26S蛋白酶体系统进行的。这些结果不仅阐明了FTBP蛋白调控植物开花的分子机制，而且为进一步挖掘调控植物开花的重要基因奠定了基础。