MicroRNAs在植物的生长发育、抗病性等代谢途径的调控中发挥重要作用。然而，在病毒与寄主互作的过程中，有关植物microRNA的功能报道较少。番茄褪绿病毒是目前生产上的重要病毒之一，申请者在前期研究中，发现番茄褪绿病毒侵染番茄后，番茄的microRNAs发现变化，其中Sly-miR169e-3p上调倍数最大，且其预测的作用靶标基因参与番茄抗病性和开花等代谢途径。在此基础上，本项目拟采用分子生物学、细胞生物学以及植物病毒学等多学科手段，研究Sly-miR169e-3p作用的标靶基因、调控方式及标靶基因的功能等，揭示Sly-169e-3p在番茄褪绿病毒侵染番茄中的功能及其分子机制。本项目的实施将有助于揭示在病毒与寄主互作过程中，寄主microRNA发挥的重要调控作用，为深入了解病毒与寄主互作机制奠定基础。

The important fuction of plant microRNAs regulating the metabolic pathway of growth and development, resistance etc, has been better understood. However, letter reports have been touched on the functions of plant microRNAs in interaction of plant and viruses. Our preliminary studies show the microRNAs of tomato (Solanum lycopersicum) are changed dramatically, of these microRNAs, Sly-169e-3p mostly up-regulate. The target genes regulated by Sly-169e-3p are involving in metabolic pathway of flower and resistance of tomato. Based on those findings, combined with recent progress on the micrRNAs, this project intends to use the integrated approaches of molecular biology, cell biology and plant virology to reveal target gene(s) of Sly-169e-3p, regulating mode of Sly-169e-3p, and functions of target gene(s), to understand the functions and mechanism of Sly-169e-3p in tomato chlorosis virus infecting tomato. The scientific significance of this project will help to uncover the regulating functions of host microRNA in interaction of plant and virus.