关键词: 桃, Ppe-miR160a, 靶基因, ARF, 生长素

Abstract: Using peach（Prunus persica）cultivar‘Xiaobaifeng’as experimental materials，we accurately determined the precise sequence of peach miR160a by using miR-RACE PCR reactions，three target genes PpARF18，PpARF17 and PpARF18-like were also cloned. RLM-5′ RACE and qualitative real-time RT-PCR were employed to validate the mode and frequency that Ppe-miR160a regulated its three target genes. Observations showed that the accurate sequence of Ppe-miR160a was different from the predicted sequence by one nucleotide at the 5′ end and 3′ end. All the three target genes（ARFs）contained highly conserved B3 and auxin resp DNA binding domains. The RLM-5′ RACE result showed that Ppe-miR160a could negatively regulate expression of its target genes by cleavage，and the target cleavage site was between the ninth and tenth nucleotide at the 5′-end of the Ppe-miR160a. Moreover，the qRT-PCR analysis revealed that compared with controls，the expression of Ppe-miR160a，three target genes and the cleavage production of three target genes at 3? ends were significantly hoisted in peach fruit by IAA. Taken together，these findings showed that Ppe-miR160a in peach fruit was involved in auxin signaling pathway by mediating the cleavage of its three target genes ARFs.

Key words: peach, Ppe-miR160a, target gene, ARF；IAA