Mechanism of Disease Production by a Satellite of Turnip Crinkle Virus

我们打算研究毒性卫星RNA C 加剧了它的辅助病毒芜菁皱纹的症状 病毒（TCV）。 RNA C不同于TCV无毒卫星RNA D和RNA F主要通过3 'TCV-同源的存在， 域 我们将分析这个3'域是否负责 为了通过感染芜菁产生卫星症状， 由无毒卫星连接的嵌合转录物 RNA C的3'结构域，并测定感染性， 症状 我们还将建立一个全面的网站- 在RNA C中的特定突变，以进一步指定 参与症状产生的卫星区域。 通过确定RNA C的二级结构，我们将 二级结构破坏与随体相关 复制和植物病害形态学。 我们将测试两个 RNA C的作用模式的模型：1）RNA C结合细胞 因子，从而滴定出这些必要的因子 或2）RNA C与假定的 植物U 7 RNA，从而干扰组蛋白mRNA加工 导致植物具有患病的形态。 第二种模式 基于RNA C与83%的 海胆U 7 RNA。 这项研究将奠定基础， 建立植物病害产生的分子基础 小的非蛋白质编码RNA。

We propose to investigate how the virulent satellite RNA C intensifies the symptoms of its helper virus, Turnip Crinkle Virus (TCV). RNA C differs from the TCV avirulent satellites RNA D and RNA F primarily by the presence of a 3'TCV-homologous domain. We will analyze whether this 3' domain is responsible for satellite symptom production by infecting turnip with chimeric transcripts composed of the avirulent satellites linked to the 3' domain of RNA C, and assaying for infectivity and symptoms. We will also create a comprehensive set of site- specific mutations throughout RNA C in order to further specify the region(s) of the satellite involved in symptom production. By determining the secondary structure of RNA C, we will correlate disruption of secondary structure with satellite replication and plant disease morphology. We will test two models for RNA C's mode of action: l) RNA C binds to cellular factor(s) thereby acting to titrate out these factors necessary for basic cellular metabolism or, 2) RNA C aneals to putative plant U7 RNA and thereby interfers with histone mRNA processing leading to plants with a diseased morphology. This second model is based on the observation that RNA C is complementary to 83% of sea urchin U7 RNA. This study will lay the groundwork for establishing the molecular basis of disease production in plants by small non-protein coding RNAs.