Caragana intermedia Kuang distributes in the arid and semi-arid area, and it could tolerate drought and extreme temperature, so it is used widely in sand fixation, soil and water preservation with high ecology value. microRNAs are one class of noncoding RNA and ubiquitous in plants, and they involves in response to a wide variety of stresses including drought, salinity, chilling temperature etc. In order to identify the drought-responsive miRNA in C. intermedia, this study constructed small RNA library of C. intermedia under drought stress, screened the drought-responsive miRNAs using high throughput sequencing and bioinformatics analysis. A total of 116 miRNAs were screened, among which 88 conservative miRNAs belonged to 33 known families and 28 novel miRNA were identified. Among the differential expression miRNAs, cin-miR164a, cin-miR164b, cin-miR168a, cin-miR168b in three drought stress treatments were down-

regulated compared with the control, and cin-novel-3, cin-novel-11, cin-novel-21 at 1 and 3 h after drought stress  were up-regulated compared with the control; cin-novel-26 had a specific expression at 3 h; 28 novel miRNA of C. intermedia were predicted 582 target genes in C. intermedia and 212 target genes in Arabidopsis thaliana by psRNATarget database. Most of the target genes responsed to drought stress. These results provided further understanding of miRNA regulation in response to drought stress in C. intermedia.

Caragana intermedia Kuang, drought stress, microRNA, high throughput sequencing, target gene prediction

中间锦鸡儿分布于干旱和半干旱地区，适应干旱和高温逆境环境，被广泛应用于固沙和水土保持，具有很高的生态价值。microRNA是一类非编码RNA，广泛分布于植物体内，参与干旱、盐、低温等多种胁迫响应。为了鉴定中间锦鸡儿中抗旱相关的miRNA，构建了干旱条件的small RNA文库，通过高通量测序和生物信息学分析，共鉴定得到116个miRNA，88个保守的miRNA属于33个已知miRNA家族和28个新miRNA，差异表达的miRNA中，cin-miR164a、cin-miR164b、cin-miR168a、cin-miR168b在三个干旱处理时间下调表达，cin-novel-3、cin-novel-11、cin-novel-21在干旱处理1和3 h上调表达，cin-novel-26 在干旱处理3 h特异表达；28个新miRNA通过psRNATarget在中间锦鸡儿中预测到582个靶基因，在拟南芥中预测到212个靶基因，大多数靶基因参与干旱胁迫响应。这些为后续研究中间锦鸡儿miRNA响应干旱胁迫奠定了基础。