玉米是重要的粮食、经济和饲用作物，高温与干旱胁迫严重影响玉米的生长发育、产量和品质。微小RNA与长链非编码RNA是近年来发现的基因表达调控因子，在生物体生长发育和胁迫响应过程中具有非常重要的生物学功能。但人们对植物中miRNA与lncRNA的相互作用机制却知之甚少。我们的研究表明玉米miRNA的表达受到高温干旱胁迫的影响，初步分析发现miRNA的靶位点位于lncRNA的内部，说明玉米miRNA可能直接结合lncRNA。因此本项目通过深入研究miRNA的表达调控与生物学功能，结合链特异高通量测序筛选与转基因功能验证，明确miRNA和lncRNA之间的内在联系；分析miRNA与lncRNA转基因株系的高温干旱响应模式，结合ChIP技术筛选并鉴定lncRNA结合位点，阐明玉米miRNA与lncRNA之间的分子调控机制。为作物抗高温干旱遗传改良提供新思路。

Maize is an economy and forage crop which play important roles in our country economy development and food security.In the past decade,high temperature and drought stress became crucial factors which seriously limits the yield of crops. Recent studies have demonstrated that miRNAs and LncRNAs are novel regulators in controlling gene expression, which play important roles in plant growth, development and stress responses. However, to our knowledge,there is no report about the mechanism between miRNAs and LncRNAs in response to high temperature and drought stress in plants to date.Our previous study indicated that the expression levels of miRNAs changed under high temperature and drought stress in Maize. And lncRNAs were predicted to be the target genes of miRNAs，suggesting a potential relationship between miRNAs and lncRNAs.Therefore, in this project, we will detect the regulation of miRNA expression in Maize,and then identify its target genes under stresses. By using the transgenic overexpressing miRNA and lncRNA lines, we will determine their biological function in response to heat and drought stress. Furthermore, the interaction points and target RNAs with the selected miRNAs will be identified by sequencing technologies. All together,we will reveal the biological function and melacular mechanism of miRNAs and target lncRNAs in response to heat and drought stress in Maize. These results obtained from this investigation will likely provide a novel pathway for plant response to the heat and drought stress and will be very helpful for better understanding the regulatory mechanism in higher plants.