Deciphering Maize Floral Regulatory Networks

近一个世纪以来，植物生物学家一直试图破译控制植物开花时间的机制。直到最近，导致植物开花的信号的性质仍然是一个完全的谜。早期的研究人员发现，一种诱导花的物质是在叶子中合成的，然后经过很长的距离运输到植物的中心茎，再到干细胞的区域，在那里真正的花是形成的。我的研究使用分子生物学、生物化学和基因组学的工具来更好地了解开花过程的本质。我们的研究围绕着对玉米开花至关重要的INDETERMINATE1基因（ID1）的研究展开。具有该基因正常拷贝的玉米植株在正常时间开花，而具有突变ID1基因的玉米植株开花很晚，并产生缺陷花。我们分离了ID1基因并用分子技术对其进行了表征。ID1编码一种锌指转录因子蛋白，该蛋白在叶片中作为其他基因的主要调节剂起作用，这表明ID1通过“开启”或“关闭”其他基因并控制叶片的远距离信号来导致玉米开花。该提案有三个主要目标：1)表征植物中组成叶片信号的分子，生化和生理成分，这些信号决定了开花时间；2)鉴定受ID1基因控制的基因；3)阐明高等生物利用ID1活性调控基因功能的基本分子机制，如ID1活性的研究。最终，我们希望确定影响开花过程的生化成分和代谢变化。此外，我们将更好地了解植物如何解释环境信号，以便它们在正确的时间开花。发现ID1如何控制开花时间可以让我们更好地了解玉米及其农业上重要的亲戚，如小麦、水稻、高粱、甘蔗和各种“能量草”，如芒草的开花情况。控制开花时间的能力对农业至关重要，因为植物协调开花以获得最佳的种子和果实产量。因此，了解开花将有助于提高重要作物的生产力。

For nearly a century plant biologists have been trying to decipher the mechanisms that control flowering time in plants. Until recently the nature of the signals that cause plants to flower remained a complete mystery. Early researchers discovered that a flower-inducing substance is synthesized in leaves and then transported a long distance to the central shoot of the plant to a region of stem cells where the actual flowers are made. My research uses the tools of molecular biology, biochemistry and genomics to better understand the nature of the flowering process. Our research revolves around the study of the maize INDETERMINATE1 gene, or ID1, which is critically important for flowering. Maize plants with a normal copy of this gene flower at the usual time, whereas maize with a mutated ID1 gene flowers very late and produces defective flowers. We isolated the ID1 gene and characterized it using molecular techniques. ID1 encodes a zinc finger transcription factor protein that acts in leaves as a master regulator of other genes, suggesting that ID1 causes flowering in maize by turning other genes 'on' or 'off' and controlling a the long distance leaf signal. There are three main goals of this proposal: 1) to characterize the molecular, biochemical and physiological components in plants that make up the leaf signals that specify time to flower; 2) to identify genes that are controlled by the ID1 gene, and 3) to work out the basic molecular mechanisms, as typified by studying ID1 activity, used by higher organisms to regulate gene function. Ultimately we would like to identify the biochemical components and metabolic changes that affect the flowering process. Moreover, we will better understand how plants interpret environmental signals so that they flower at the correct time. Discovering how ID1 controls flowering time could lead to a better understanding of flowering in maize as well its agriculturally important relatives such as wheat rice, sorghum, sugarcane and various 'energy grasses' such as Miscanthus. The ability to control time to flowering is of vital importance to agriculture because plants coordinate flowering for optimal seed and fruit production. Therefore understanding flowering will help to improve the productivity of vital crop plants.