Photoperiodic control of floral transition in Arabidopsis thaliana

拟南芥花转变的光周期控制

• 批准号: 44335467
• 负责人: Professor Dr. Markus Schmid
• 金额: --
• 依托单位: Department of Plant Physiology
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/44335467?language=en
• 关键词: Photoperiodic; control; floral; transition; Arabidopsis

To ensure reproductive success, plants have developed an elaborate genetic network that integrates endogenous and environmental factors to correctly time the onset of flowering. One of the most important factors that control this developmental switch is day length, or photoperiod. Based on grafting experiments it has been proposed that photoperiod is perceived in leaves where it leads to the induction of a flower-forming substance called florigen . The florigen is than transmitted to the shoot apex where it induces the transition to flowering. The molecular nature of the florigen has eluded characterization for the past 70 years, but recent data suggest that the mRNA of FLOWERING LOCUS T (FT) can be transmitted from the leaves to the apex where the FT protein interacts with a bZIP transcription factor FD to induce flowering. We have identified a negative regulator of floral transition, SCHLAFMÜTZE (SMZ), which represses the induction of FT in leaves. Results from misexpression of SMZ and other genes that affect either FT transcription or mRNA stability, or the FT protein level suggest the FT protein movement might be crucial for the induction of flowering. Here we propose a series of experiments to investigate the function of SMZ in regulating FT transcription, including the potential role of miR172 in this process. We will further analyze whether FT protein is able to move from the leaves to the apex. Specifically we will address the question whether FT protein movement is possible at all, as is suggested from our preliminary data, and whether this movement is necessary and sufficient to induce flowering. Finally we will analyze the role of FT/FD protein complex at the shoot apex with an emphasis on identifying direct targets.

为了确保繁殖的成功，植物已经发展出一个复杂的遗传网络，整合了内源和环境因素，以正确地确定开花的开始时间。控制这种发育开关的最重要因素之一是昼长或光周期。根据嫁接实验，有人提出光周期在叶片中被感知，它导致一种称为花原的花形成物质的诱导。然后将花原传递到茎尖，在那里诱导向开花的过渡。开花基因的分子性质在过去的70年里一直没有得到表征，但最近的数据表明，开花基因座T （FT）的mRNA可以从叶片传递到顶端，在那里FT蛋白与bZIP转录因子FD相互作用诱导开花。我们已经确定了一个负调控的花过渡，SCHLAFMÜTZE (SMZ)，抑制诱导FT在叶片。SMZ和其他影响FT转录或mRNA稳定性的基因的错误表达，或FT蛋白水平的结果表明，FT蛋白的运动可能对诱导开花至关重要。在这里，我们提出了一系列实验来研究SMZ在调节FT转录中的功能，包括miR172在这一过程中的潜在作用。我们将进一步分析FT蛋白是否能够从叶片移动到顶端。具体来说，我们将解决FT蛋白运动是否可能的问题，正如我们的初步数据所建议的那样，以及这种运动是否必要和足以诱导开花。最后，我们将分析FT/FD蛋白复合物在茎尖的作用，重点是确定直接靶点。