The role of the 'Antiflorigen' TFL1 in Arabidiopsis Development

“抗花素”TFL1 在拟南芥发育中的作用

• 批准号: 1557529
• 负责人: Doris Wagner
• 金额: $ 70万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-15 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1557529&HistoricalAwards=false
• 关键词: role; Antiflorigen; TFL1; Arabidiopsis; Development

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.

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连续的阶段。在营养生长过程中，植物将阳光中的能量转化为资源。当植物开始开花时，积累的资源就被整合到种子中。因此，开花的时间既影响植物生物量生产（生物燃料生产），也影响果实和种子的数量（产量）。植物根据环境线索调整开花时间，最重要的是一年中的季节和温度。当季节性的信号最适合开花时，植物会产生一种叫做“成花素”的物质。成花素在整个植物中移动，并引发花朵的产生。一种名为“抗成花素”的密切相关的物质在没有季节性提示的情况下阻止花的形成。尽管它的重要功能，它是不明白如何抗成花素防止开花，也不知道如何克服抗成花素活性，允许花的形成。拟议的活动将解决这些缺陷。所获得的见解可用于增强作物物种的理想性状。这项研究将与莫里斯植物园的国家公民科学“萌芽项目”一起与公众讨论。在每年的高中夏季研究学院和教师专业发展实践期间，将通过讲座和讲习班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成花素的作用和调节相关的研究。第一个是TFL1如何抑制花的形成。使用染色质免疫沉淀（ChIP）和基因表达分析，该提案将确定直接抑制基因的抗成花因子TFL1之前，花的形成。将采用候选基因和无偏基因组方法。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，所提出的活动将阐明TFL1是如何被募集到其靶位点的。要解决的第二个问题是如何克服TFL1介导的抑制，以允许在感知诱导线索时形成第一朵花。利用生物化学、遗传学和基因组学方法，所提出的活动将检验以下假设：FT成花素竞争进入共享的靶基因座，随后LFY和AP 1对TFL1表达的负反馈在这一过程中起关键作用。数学建模将被用来确定未被发现的相互作用是否解释了系统的行为。