干旱是制约玉米生产的主要因素之一。花器官分化期,即从减数分裂到四分体花粉母细胞的时期,对干旱胁迫最为敏感,该阶段的干旱胁迫可引起配子发育不正常,造成大幅度的减产。然而干旱胁迫对这一时期玉米雄穗发育影响的分子机理尚不清楚。miRNA作为一类非编码小分子RNA在基因的表达调控上起着重要作用，不仅参与作物的发育调控，而且在作物逆境胁迫中具有重要作用。本项目以我们前期筛选的耐旱玉米自交系“PHBA6” 和干旱敏感自交系“吉63”的雄穗为研究对象，对miRNA调控玉米雄穗花器官分化期干旱胁迫适应性的分子机制进行研究。通过小RNA和数字基因表达谱测序、生物信息学分析、RT-qPCR和转基因技术鉴定出玉米雄穗花器官分化期耐旱相关的miRNA和其靶基因，并研究其生物学功能，将有助于我们了解miRNA在植物生长发育和逆境信号转导中的作用，并为揭示干旱胁迫下玉米雄穗发育分子机制和培育耐旱玉米品种提供理论基础。

Drought is one of the main factors restricting the production of corn. The period from meiosis to tetrad break-up in anthers is one of the most sensitive to drought, which can cause abnormal gamete development, resulting in a substantial reduction of yield. However, the molecular mechanism of drought on tassel development of this period remains unclear. As a class of non-coding small RNA, miRNA plays an important role in the regulation of gene expression, which involved in the regulation of crop development and adaptations to environmental stresses. The goal of this project is to uncover the molecular mechanisms of miRNA regulation on tassel adaptation to drought at meiotic stage base on drought-tolerant maize inbred "PHBA6" and drought sensitive inbred "Ji 63" by combing with small RNA sequencing, digital gene expression profiling, bioinformatics analysis, RT-qPCR and transgenic technology. Identification and biological functional analysis of drought-related miRNA and its target genes at meiotic stage of corn tassel will enable a better understanding of the role of miRNAs in plants growth and stress signal transduction, as well as provide a theoretical basis for understanding the molecular mechanism of maize tassel development under drought stress and cultivating drought-tolerant maize varieties.