Plasticity of flowering time in response to environmental signals in Arabidopsis thaliana

开花是由不同的环境线索精确控制的。这些反应有助于植物适应不同的环境，并优化作物产量。主要在拟南芥中进行的遗传和分子分析已经确定了赋予对环境的不同反应并整合内源和环境线索以控制花转变的调控途径。这些途径作用于植物的不同组织，但最终影响茎分生组织的开花。对这些途径以及它们是如何整合的完整理解将解释开花反应的可塑性如何在相同基因型的植物中被赋予，以及品种之间的遗传变异如何影响这种可塑性。反过来，这些知识将提高我们为不断变化的环境条件培育作物的能力。本研究旨在探讨拟南芥开花时间调控中可塑性的分子基础。thaliana，重点是两个关键的环境线索，增加环境温度和不同的白天长度。由于介导这些反应的途径最终汇聚在芽分生组织启动转录重编程，我们将开发的INTACT系统来描述转录的变化，发生在定义的空间区域的分生组织通过一个时间序列，在响应日长的变化。然后，我们将使用来自INTACT分析的数据来解决与分生组织信号整合相关的具体问题。我们将调查染色质景观在拍摄顶端分生组织（SAM）在过渡到开花和相关的转录活性和剪接模式，以应对高环境温度。这种分析将允许将这些数据与在确定共同和不同过程的日长系列期间获得的数据进行比较。此外，我们将调查不同的信号通路的整合在肋骨分生组织，光周期和赤霉酸（GA）信号收敛。因此，该项目将利用开花和基因组技术的进步作为一个平台，解剖在全基因组规模上管理发育可塑性的基本机制。我们的研究结果将是感兴趣的广大观众，并将有助于回答进化上的重要问题，环境信号通路的优先顺序和整合在拍摄分生组织，以及有多少表观遗传调控和选择性剪接有助于花的过渡。最终，这些知识将有助于预测植物可利用的机制，以应对环境变化，并将有助于可持续农业。

Flowering is precisely controlled by diverse environmental cues. These responses contribute to the adaptation of plants to different environments and to the optimisation of crop yields. Genetic and molecular analyses performed mainly in Arabidopsis thaliana have identified regulatory pathways that confer different responses to the environment and integrate endogenous and environmental cues to control the floral transition. These pathways act in different tissues of the plant but ultimately influence flowering at the shoot meristem. A complete understanding of these pathways and how they are integrated will decipher how plasticity in flowering response is conferred among plants of the same genotype and how genetic variation between varieties impacts on this plasticity. In turn such knowledge will increase our capacity to breed crops for changing environmental conditions. We propose to investigate the molecular basis of plasticity in flowering-time control in A. thaliana, with a focus on two crucial environmental cues, increases in ambient temperature and different day lengths. As the pathways mediating these responses ultimately converge on the shoot meristem to initiate transcriptional reprogramming we will develop the INTACT system to describe the transcriptional changes that occur in defined spatial zones of the meristem through a temporal series in response to changes in day length. Then, we will use the data from the INTACT profiling to address specific issues related to signal integration at the meristem. We will investigate the chromatin landscape at the shoot apical meristem (SAM) during the transition to flowering and correlate this to transcriptional activity and splicing patterns in response to high ambient temperatures. Such analyses will allow comparison of these data with those obtained during the day-length series identifying common and distinct processes. In addition, we will investigate the integration of different signalling pathways in the rib meristem, where photoperiod and gibberellic acid (GA) signalling converge. Thus, this project will employ flowering and advances in genomic technologies as a platform for dissecting basic mechanisms that govern developmental plasticity on a whole-genome scale. Our results will be of interest to a wide audience, and will help to answer the evolutionarily important questions of how environmental signalling pathways are prioritized and integrated at the shoot meristem as well as how much epigenetic regulation and alternative splicing contributes to the floral transition. Ultimately such knowledge will help predict the mechanisms available to plants to manipulate the timing of the floral transition in response to environmental changes and will contribute to sustainable agriculture.