Proximal Distal Patterning During Maize Leaf Development

智力优势。玉米叶片由上部的光合叶片和下部的叶鞘组成。去除或改变叶舌区域的突变减少了叶片相对于叶鞘的角度，导致叶片直立延伸。因此叶舌区域有助于确定植物形状，了解结构如何发展将为作物改良提供新的工具。叶舌区域在发育早期的一个限制性位点可见，称为前叶舌带，最初以增加细胞分裂、细胞扩增和局部基因表达为标志。生长素载体蛋白的荧光标记也定位于叶舌前带，表明激素信号在建立该位点中的作用。为了理解叶舌发育的机制，将使用荧光标记的集合来绘制在早期叶舌发育期间表达的顺序变化。将使用激光捕获显微切割然后进行RNA测序来生成前叶舌区域中的基因表达谱。沿叶轴的三个区域沿着将被捕获，包括前叶舌带本身，邻接叶片和对着鞘组织。将正常植物与突变体进行比较，以鉴定当叶舌生长改变时基因组水平上的表达变化。生物信息学工具将用于从这些表达目录中选择候选基因进行进一步研究。将通过qRT-PCR验证所选基因，并通过整体原位杂交研究其表达模式。这项研究将确定的顺序和潜在的相互作用的因素，使叶舌，并将提供新的遗传工具，操纵叶的形状。更广泛的影响。叶片倾角是玉米等粮食作物的重要农艺性状。由于叶舌结构的变化而具有更多直立叶片的植物，如果在更小的空间内能够发生最佳光合作用，则可能具有更高的作物产量。玉米叶舌突变体也是教学生发育遗传学和基因组学的极好工具。该项目将专门为社区大学学生提供夏季研究机会，并将与怀俄明州（UW）建立的教育项目合作开发社区大学教学模块。教学模块将使用在华盛顿大学科学数学教学中心开发的方法进行评估，并通过华盛顿大学传播到参与的社区学院。研究数据和教学模块将张贴在项目网站上，并提供给研究界和公众。

Intellectual Merit. Maize leaves consist of an upper photosynthetic blade separated at the ligule region from a lower enclosing sheath. Mutations that remove or alter the ligule region reduce the angle of the blade relative to the sheath, causing the leaves to extend upright. The ligule region thus helps to determine plant shape, and understanding how the structure develops will provide new tools for crop improvement. The ligule region is visible early in development at a restricted site, called a pre-ligule band, marked initially by increased cell division, cell expansion and localized gene expression. A fluorescent marker for an auxin carrier protein also localizes to the pre-ligule band, suggesting a role for hormone signaling in establishing the site. To understand the mechanism of ligule development, a collection of fluorescent markers will be used to map sequential changes in expression during early ligule development. Gene expression profiles in the pre-ligule region will be generated using laser capture microdissection followed by RNA sequencing. Three regions along the leaf axis will be captured, including the pre-ligule band itself, adjoining blade and subtending sheath tissue. Normal plants will be compared to mutants to identify expression changes on a genomic level when ligule growth is altered. Bioinformatic tools will be used to select candidate genes from these expression catalogs for further study. The selected genes will be validated by qRT-PCR, and their expression patterns studied by whole mount in situ hybridization. This research will identify the sequential and potentially interacting factors needed to make a ligule and will offer new genetic tools for manipulating leaf shape. Broader impacts. Leaf blade angle is an important agronomic trait in grain crops, such as maize. Plants with more upright leaves, caused by changes in ligule structure, may have higher crop yield if optimal photosynthesis can occur in less space. Maize ligule mutants are also excellent tools for teaching students about developmental genetics and genomics. The project will provide summer research opportunities specifically to Community College students and will develop Community College teaching modules in collaboration with education programs established at the University of Wyoming (UW). The teaching modules will be assessed using methods developed at the Science Math Teaching Center at UW and disseminated through UW to participating Community Colleges. Research data and teaching modules will be posted at a project website and made available to the research community and general public.