Proximal Distal Patterning During Maize Leaf Development

智力上的功绩。玉米叶片由叶舌区域的上部光合作用叶片与下部包围叶鞘分离而成。移除或改变叶舌区域的突变会减少叶片相对于叶鞘的角度，导致叶片垂直伸展。因此，叶舌区域有助于确定植物的形状，了解该结构是如何发展的将为作物改良提供新的工具。舌状区在发育早期的一个被称为舌前带的限制性部位可见，最初的标志是细胞分裂增加、细胞扩张和基因表达局部化。生长素载体蛋白的荧光标记也定位在舌前带，表明激素信号在建立该部位中发挥了作用。为了了解舌叶发育的机制，将使用一系列荧光标记来定位舌叶发育早期表达的连续变化。将使用激光捕获显微切割和RNA测序来生成舌前区的基因表达谱。沿着叶轴的三个区域将被捕获，包括前叶舌带本身、相邻的叶片和对生鞘组织。将正常植物与突变体进行比较，以确定当叶舌生长发生变化时，基因组水平上的表达变化。生物信息学工具将被用来从这些表达目录中选择候选基因进行进一步研究。所选基因将通过qRT-PCR进行验证，并通过整体安装原位杂交来研究其表达模式。这项研究将确定形成叶舌所需的顺序和潜在的相互作用因素，并将为操纵叶片形状提供新的遗传工具。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。如果能在较小的空间内进行最佳的光合作用，由于叶舌结构的变化而导致的叶片更竖直的植物可能会有更高的作物产量。玉米叶舌突变体也是教授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学院的学生提供暑期研究机会，并将与怀俄明大学(UW)建立的教育项目合作开发社区学院的教学模块。这些教学模块将使用威斯康星大学科学数学教学中心制定的方法进行评估，并通过威斯康星州大学传播到参与的社区学院。研究数据和教学单元将张贴在一个项目网站上，并向研究界和普通公众提供。

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.