Abstract:

To investigate the function of microRNA171（miR171）in cucumber，four precursors Csa-miR171a，Csa-miR171b，Csa-miR171c，Csa-miR171d of Csa-miR171 family genes were cloned in the northern Chinese cucumber‘Beijingjietou’and followed by sequence alignment and phylogenetic analysis. Target genes of the mature sequence of Csa-miR171 were predicted and functional analysis was performed in Arabidopsis by genetic transformation. The results showed that the two mature sequences，Csa-miR171a and Csa-miR171b were cleaved from the four Csa-miR171 precursors. Phylogenetic analysis showed that Csa-miR171a，Csa-miR171b，Csa-miR171c，Csa-miR171d were closer to Cme-miR171e，Cme-miR171c，Cme-miR171a，Cme-miR171b in melon than those in Arabidopsis，rice and tomato，etc. GRAS transcription factor family was predicted to be the main target gene of Csa-miR171. Overexpression of Csa-miR171a in Arabidopsis significantly affected the phenotypes including leaf morphology and leaf color，blooming time，root，fruit and floral morphology.

Key words: cucumber, microRNA171, clone, target gene prediction, transgenic