The role of the 'Antiflorigen' TFL1 in Arabidiopsis Development

植物生物学中一个长期存在的问题是，植物如何“决定”何时开花。植物在其生命周期中经历了连续的阶段。在营养生长发育过程中，植物将阳光中的能量转化为资源。当植物切换到开花时，积累的资源被整合到种子中。因此，开花的时间既影响植物的生物量生产(生物燃料生产)，也影响生产的果实和种子的数量(产量)。植物根据环境信号调整花朵形成的时间，最重要的是一年中的季节和温度。当季节信号最适合开花时，植物会产生一种被称为“成花素”的物质。成花素在整个植物中移动，并触发花朵的产生。一种与之密切相关的物质“抗花素”在没有季节性提示的情况下阻止了花的形成。尽管抗花素具有重要的功能，但目前还不清楚抗花素是如何阻止开花的，也不知道抗花剂活性是如何被克服以促进花的形成的。拟议的活动将解决这些不足之处。所获得的洞察力可以用来增强作物物种的可取特性。这项研究将在莫里斯植物园与普通公众一起讨论，与国家公民科学“萌芽计划”一起进行。在一年一度的高中暑期研究学院期间，将通过讲座和研讨会以及教师专业发展实践，为加强高中教育做出贡献。最后，本科生将在实验课和研究实验室中从事与抗花剂的作用和调控相关的研究。第一个问题是TFl1如何抑制花形成的开始。利用染色质免疫沉淀(CHIP)和基因表达分析，该提案将确定在花形成开始之前直接被抗花剂TFL1抑制的基因。候选基因和无偏见的基因组方法都将被使用。后续的分子和遗传学研究将评估TFl1靶基因对TFl1功能的生物学贡献。最后，拟议的活动将阐明TFl1是如何被招募到其目标基因座的。第二个要解决的问题是如何克服TFL1介导的抑制，以便在感知诱导线索时形成第一朵花。利用生化、遗传和基因组方法，拟议的活动将检验这样的假设，即FT成花基因竞争获得共享的靶基因，以及随后LFY和AP1对TFl1表达的负反馈在这一过程中发挥关键作用。数学建模将用于确定未覆盖的交互是否解释系统的行为。

A longstanding question in plant biology is how plants "decide" when to flower. Plants go through successive phases in their lifecycle. During vegetative development plants convert the energy from sunlight into resources. When plants switch to flowering, the accumulated resources are incorporated into the seeds. As a consequence, the timing of flowering impacts both plant biomass production (biofuel production) and the number of fruits and seeds produced (yield). Plants adjust the time to flower formation based on environmental cues, most importantly the season of the year and the temperature. When seasonal cues are optimal for flowering, plants produce a substance called "florigen". Florigen moves throughout the plant and triggers production of flowers. A closely related substance named "antiflorigen" prevents flower formation in the absence of the seasonal cue. Despite its important function, it is not understood how antiflorigen prevents flowering, nor how antiflorigen activity is overcome to allow flower formation. The proposed activities will address these deficiencies. Insight gained can be used to enhance desirable traits in crop species. The research will be discussed with the general public in conjunction the national citizen science "Project Bud Burst" at the Morris Arboretum. Contributions to enhancing high school education will be made through lectures and workshops during the yearly high school summer research academy and hands on teacher professional development. Finally, undergraduates will be engaged in research related to the role and regulation of antiflorigen in laboratory classes and in the research lab.This proposal will address two general questions. The first is how TFL1 represses onset of flower formation. Using chromatin immunoprecipitation (ChIP) and analysis of gene expression, the proposal will identify the genes directly repressed by the antiflorigen TFL1 prior to the onset of flower formation. Both candidate gene and unbiased genomic approaches will be employed. Follow-up molecular and genetic studies will assess the biological contribution of the TFL1 target genes to TFL1 function. Finally, the proposed activities will elucidate how TFL1 is recruited to its target loci. The second question to be addressed is how TFL1-mediated repression is overcome to allow formation of the first flower upon perception of inductive cues. Using biochemical, genetic and genomic approaches, the proposed activities will test the hypothesis that competition by the FT florigen for access to shared target loci and subsequent negative feedback by LFY and AP1 on TFL1 expression play critical roles in this process. Mathematical modeling will be used to determine whether the uncovered interactions explain the behavior of the system.