非编码RNA在植物生长发育以及抵抗外界胁迫过程中，发挥着重要作用。当前，对长链非编码RNA（lncRNA）产生机制以及作用方式的研究并不透彻。前期研究证实，拟南芥NIA基因负链转录一条与正链mRNA互补的lncRNA（NAT-NIA）。在黄瓜花叶病毒（CMV）侵染的拟南芥中，我们克隆到来源于NIA基因并且依赖于NAT-NIA的nat-siRNA。CMV侵染诱导了nat-siRNA的积累，同时抑制了NIA基因的表达。本项目拟阐明NAT-NIA和nat-siRNA的产生机制，以及NAT-NIA和nat-siRNA调控NIA基因响应CMV侵染的作用机理。利用CMV编码的沉默抑制子（VSR）2b，明确RNA沉默在NIA基因表达调控中发挥的作用。研究结果将加深VSR蛋白在宿主与病毒互作中复杂功能的理解；同时将丰富lncRNA和nat-siRNA的产生和调控模式，及其对应答外界生物胁迫的基础理论。

Non-coding RNA (ncRNA) plays a key role in plant development and responding to abiotic and biotic stimulation. Biological functions of long ncRNA (lncRNA) are largely unknown. Our previous investigations have revealed that a natural antisense transcript (NAT) derived from Arabidopsis Nitrate Reductase gene (NIA). We discovered a set of natural antisense transcript siRNA (nat-siRNAs) derived from NIA genes in Cucumber mosaic virus (CMV) infected plants. CMV infection induced the nat-siRNA accumulation, and down-regulated NIA mRNAs. This project aims to deciphering the mechanism of NAT-NIA and nat-siRNA in regulation of NIA gene response to CMV infection. Roles of RNAi proteins in regulation of NIA gene will be investigated by the aid of the RNAi suppressor activity of 2b which encoded by CMV. The results will increase our knowledge about the function of lncRNA and sRNA, as well as the key role in responding to abiotic and biotic stimulation.