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