MiRNA在植物的生长发育和逆境胁迫响应过程中发挥着重要的调控作用。玉米作为国家重要的经济作物，提高和改良其在逆境胁迫下的产量品质和农艺性状意义重大。目前有关玉米miRNA在多种非生物胁迫，如高盐、干旱、低氮、低磷等中的作用已有相关报道，但高温胁迫响应相关miRNA的研究还很少。高温胁迫造成玉米籽粒败育，严重限制玉米产量，玉米耐受高温胁迫的机理亟待研究。本项目将对玉米高温胁迫下参与响应的miRNA及其靶基因进行鉴定和功能研究，通过构建小RNA文库、mRNA文库、降解组文库和核糖体保护序列文库，以及基因过表达和基因沉默等分子和遗传学手段，鉴定获得高温胁迫相关miRNA及其靶基因，并对其属性、表达模式、具体作用机制，以及胁迫下玉米miRNA下游基因的表达调控网络进行深入分析。本研究的开展将有助于理解和阐释玉米miRNA响应高温胁迫的调控机制，为玉米在逆境胁迫下的性状改良提供理论依据和新途径。

MicroRNAs (miRNAs) play essential roles in plant growth, development and stress responses. Maize is one of the most important economic crops in China, and it is of great significance to improve maize yield, quality and agronomic traits under stress environments. It has been reported that miRNAs play roles in multiple abiotic stresses, such as high salinity, drought, and nitrogen or phosphate deficiency in maize. However, the roles of miRNAs in high temperature stress haven’t been well studied. High temperature leads to kernel abortion and seriously limits the maize yield, so it is urgent to study the mechanisms of high temperature tolerance in maize. This project aims to characterize and study the function of high temperature induced miRNAs and their target genes in maize. Small RNA-seq, mRNA-seq, degradome-seq and ribosome protected fragments-seq will be constructed, and the gene overexpression and gene silencing strategies will be taken as well to identify the high temperature induced miRNAs and their targets. The categories, expression profiles, functional mechanisms and the downstream regulatory network of these miRNAs and their targets will be analyzed as well. This study will extend our knowledge in the aspect of understanding the regulatory mechanism of maize miRNAs in response to high temperature stress, and accomplishment of this project will provide theoretical basis and novel strategies for trait improvement of maize under adversity stresses.