Sequence Requirements for Small RNA Targeting in Plants

智力优势：给定生物体中的每个细胞都包含完全相同的DNA基因组，然而生物体中包含许多细胞类型，这些细胞类型是分化的，并且为某些功能高度特化。具有相同基因组的不同细胞类型之间的功能差异是由dna编码基因的子集决定的，这些基因被激活（打开）或沉默（关闭）。因此，基因表达的控制（开或关）在复杂生物体的细胞功能形成中起着重要作用。一种类型的基因表达控制机制是由小调控rna指导的。小rna的功能是通过RNA-RNA互补来识别细胞中的靶rna。从本质上讲，如果给定的小RNA在序列上与给定的靶RNA匹配良好，则该靶RNA将被阻止进一步利用，并且靶基因的表达将被关闭。基于小rna的基因表达控制方法在植物中占有重要地位，在植物正常生长和农业生产力中发挥着重要作用，可以在需要控制基因表达的生物技术应用中得到开发。该项目旨在了解小rna识别植物靶标的规则。该项目将专门研究允许小RNA识别和调节植物靶标所需的匹配RNA碱基的范围和结构。该项目的结果将是更全面地了解小rna介导的基因表达系统如何能够将其少数目标rna与细胞中存在的数千个非目标rna区分开来。更广泛的影响：已知小rna控制植物生长发育的关键方面，其中许多在作物植物中具有农业意义。小rna还会抑制植物基因组中寄生的大部分，即所谓的“垃圾DNA”。小rna的操作已经在许多植物生物技术应用中发挥了关键作用，但如果没有对小rna如何工作的透彻理解，这些应用是有限的。本项目提供的对小RNA靶标鉴定的理解，应该会促进这方面的应用。该项目还涉及培养博士和本科水平的科学家，这是国家的一个重要目标。该项目的目标之一将作为在宾夕法尼亚州立大学开发RNA生物学新实验课程的跳板，从而提高这些学生的科学素养和教育水平。

Intellectual Merit: Every cell in a given organism contains exactly the same DNA genome, yet the organism contains many cell types that are differentiated and highly specialized for certain functions. The functional differences between various cell types with the same genome are dictated by the subset of DNA-encoded genes that are activated (turned on) or silenced (turned off). The control of gene expression (on or off) thus plays a fundamental role in shaping cellular function in complex organisms. One type of gene expression control mechanism is directed by small regulatory RNAs. Small RNAs function to identify target RNAs in the cell by RNA-RNA complementarity. Essentially, if a given small RNA has a good match in sequence to a given target RNA, that target RNA will be prevented from being utilized further, and expression of the target gene will be turned off. Small RNA-based methods of gene expression control are prominent in plants, play important roles in normal plant growth and agricultural productivity, and can be exploited in biotechnological applications where control of gene expression is desirable. This project is seeking to understand the rules by which small RNAs recognize their targets in plants. The project specifically will examine the extent and configuration of matching RNA bases required to allow small RNAs to recognize and regulate their targets in plants. The outcome of this project will be a much more complete understanding of how the small RNA-mediated gene expression system is able to discriminate its handful of target RNAs from the thousands of non-target RNAs present in the cell. Broader Impacts: Small RNAs are known to control key aspects of plant growth development, many of them with agricultural significance in crop plants. Small RNAs also dictate the repression of vast portions of plant genomes comprised of parasitic, so-called junk DNA. Manipulation of small RNAs already plays a key role in many plant biotechnology applications, but without a thorough understanding of how small RNAs work, these applications are limited. The understanding of small RNA target identification provided by this project should enhance such applications. This project also involves training of scientists, a critical national goal, both at the Ph.D. level and undergraduate level. One of the project goals will be used as a springboard for developing a new laboratory course in RNA Biology at Pennsylvania State University, thus enhancing scientific literacy and education of these students.