野生二粒小麦条锈菌胁迫响应相关miRNA的鉴定与功能分析

MicroRNAs (miRNAs) play essential roles in plant adaptation to stresses through regulating target genes negatively at the post-transcriptional levels. In our previous work, we found that wheat lines carrying wild emmer gene Yr15 showed a range of resistance responses to the same rust isolate. It remains unclear whether and how miRNAs regulate Yr15-mediated stripe rust resistance in it. In the present study, we will use deep sequencing technology to profile the stripe rust-responsive miRNAs and their targets in wild emmer. We will use bioinformatics, northern blotting, quantitative real-time PCR, transient expression system in tobacco, and transgenic technology to dissect the role of miRNAs related to Yr15 in regulating stripe rust resistance. We expect that our works will make the pavement for revealing the stripe rust resistance mechanism in wild emmer and broad-spectrum resistance molecular breeding in wheat.

miRNA负向调控目标基因表达，从而对植物响应外界逆境胁迫产生重要作用。前期研究发现，源于野生二粒小麦的功能型广谱抗条锈病基因Yr15在不同小麦材料中，对相同条锈菌小种表现出抗性差异。为探究miRNA调控与Yr15介导的抗性差异关系，本研究拟鉴定野生二粒小麦响应条锈菌胁迫相关miRNA及其靶基因，进一步利用生物信息学、基因定量表达、烟草瞬时表达、转基因过表达等方法对Yr15相关miRNA进行功能分析。预期本研究结果可为阐释野生二粒小麦条锈病抗性分子机制和广谱抗性分子育种奠定重要基础。

miRNA调控靶基因表达，在植物响应外界逆境胁迫及适应性的过程中起重要作用。小麦祖先种野生二粒小麦具有优异的逆境胁迫适应性，但胁迫响应相关的miRNA的功能研究缺乏。本项目通过miRNA测序和降解组测序鉴定了野生二粒小麦响应条锈菌胁迫相关miRNA及其靶基因。利用表达特性分析、烟草瞬时表达系统、荧光报告系统初步验证了关键miRNAs与靶基因的剪切关系。对野生二粒小麦中条锈菌胁迫高表达的miR319进行转基因功能分析，表明miR319参与对小麦抗性调控。本研究为揭示miRNA参与调控小麦抗性的分子机理奠定基础，为实现精准指导作物抵御病虫害的改良提供理论依据。