Development of Vectors for Virus-Induced Plant Gene Silencing

植物基因组测序的能力导致了大量新的开放阅读框（orf）的鉴定。未来的挑战是获得通过这些项目已经确定的许多已知和新基因的功能信息。为此，正在进行系统的努力，利用生物信息学和高通量程序大规模地表征基因。大多数高通量方法需要分析核酸：mrna， cdna或基因组序列。这些数据提供了有关基因表达、基因组序列比较和DNA结合蛋白靶点的信息。然而，关于基因的许多信息来自于对基因功能和基因产物的分析。因此，在后基因组时代，需要大规模的功能基因组学方法将序列信息转化为功能信息。最近开发的一种称为病毒诱导基因沉默（VIGS）的副遗传方法提供了快速了解植物基因功能的手段。这种策略被称为“准遗传”，因为它在没有宿主基因组突变的情况下有效地产生了遗传抑制因子。该项目的长期目标是开发植物功能基因组学工具，这将有助于了解植物抗性基因如何识别病原体激发子并发出信号诱导防御反应，最终阻止病原体传播。具体目标是：(1)利用VIGS方法开发植物功能基因组学的病毒载体；(2)利用VIGS方法鉴定抗病信号成分的“全局”和“特异性”抑制因子。本提案中开发的工具将对深入了解植物信号网络具有很大的实用价值。本项目开发的工具和信息将提供给科学界用于植物信号研究。最终，从这些研究中获得的知识将为改良作物的工程提供新的策略。

The ability to sequence plant genomes has resulted in the identification of large numbers of novel open reading frames (ORFs). The challenge ahead is to gain information about the function of many known and novel genes that have been identified through these projects. To this end, systematic efforts are underway to characterize the genes on a large scale using both bioinformatics and high throughput procedures. Most of the high throughput methods entail analyzing nucleic acids: mRNAs, cDNAs, or genomic sequences. These data provide information about gene expression, genome sequence comparisons and target sites for DNA binding proteins. However, much information about genes comes from the analysis of gene function and gene products. Therefore, in the post-genomic era, large-scale functional genomics approaches are necessary for converting sequence information into functional information. A recently developed para-genetic approach called virus-induced gene silencing (VIGS) offers rapid means of gaining insight into gene function in plants. The strategy is termed 'para-genetic' because it effectively creates genetic suppressors in the absence of host genome mutation. The long-term goal of the project is to develop tools for plant functional genomics that will help to understand how plant resistance genes recognize pathogen elicitors and signal the induction of defense responses that ultimately halt the pathogen spread. The specific objectives are to: (1) develop viral vectors for plant functional genomics using a VIGS approach, and (2) identify 'global' and 'specific' suppressors of disease resistance signaling components using VIGS approach. The tools developed in this proposal will be of great utility to gain insight into plant signaling networks. The tools and information developed in this project will be made available to the scientific community for plant signaling studies. Eventually, the knowledge gained from these studies will provide new strategies for the engineering of improved crops.