探究pri-miRNA自然结构多样性在植物响应干旱胁迫中的作用

MicroRNAs(miRNAs)是一类重要的调控基因表达的小RNA。它们由其初级转录本(pri-miRNAs)经过一系列精确地切割加工而形成。植物pri-miRNA具有多种多样的二级结构。现有的研究表明人工改变pri-miRNA的结构会影响miRNA的生成，但自然群体中pri-miRNA的结构多样性是否影响miRNA的生成还尚不清楚。本项目拟以响应干旱胁迫的pri-miRNA为研究对象，探究其在拟南芥自然群体中的结构多样性与成熟miRNA生成的关系，挖掘影响miRNA生成的重要特征结构，进一步研究结构多样性对植物应答干旱胁迫的影响。另外，本项目还拟将该结果转化到作物，在玉米中筛选高效生成响应干旱胁迫miRNA的pri-miRNA结构。研究结果有助于阐明pri-miRNA结构多样性对植物适应环境的生物学意义，并为优化改良作物抗逆性状过程提供了新的思路和证据。

MicroRNAs (miRNAs) are an important group of small RNAs functioning in gene regulation. They are formed by a series of precise cleavage and processing steps conducted on the respective primary miRNAs (pri-miRNAs). Plant pri-miRNAs are heterogeneous in secondary structure. While it is known that genetic manipulation of their structure can impact miRNA biogenesis, it remains unclear if this applies to natural populations, which exhibit high diversity in pri-miRNA structures. In this study, we propose to analyze the structural diversity of drought responsive pri-miRNAs in different Arabidopsis thaliana ecotypes. Correlations of pri-miRNA structures and mature miRNA biogenesis will be explored to determine which structural characteristics affect the efficiency of miRNA biogenesis and to illustrate its impact on the plant’s response to drought stress. Moreover, we propose to translate the results into a crop system, by identifying pri-miRNAs with structures that enable the most efficient production of drought responsive miRNAs in maize. Thereby, our study will shed light on the significance of pri-miRNA structure in plant adaptation to its local environment and facilitate the optimization of breeding procedures for stress resistant crops.