Characterization of the miR165 family and its target gene Pp-ATHB8 in Prunus persica

Abstract A study to identify and validate Prunus persica microRNAs belonging to the ppe-miR165 family was conducted using miR-RACE where the expression of these miRNAs could be detected in leaves, flower buds, flowers and fruits of P. persica by quantitative real-time PCR (qRT-PCR) with some members of this miRNA family exhibiting tissue-specific expression. In addition, Pp-ATHB8 which is one of the potential target genes for ppe-miR165 family was experimentally verified by PPM-RACE and RLM-RACE, from which the cleavage sites of the target mRNA were mapped and the expression patterns of cleaved fragments also detected, thus demonstrating the mode by which ppe-miR165 regulates the target gene Pp-ATHB8 . Furthermore, spatiotemporal expression levels of the target gene and its cleaved fragments were analyzed by qRT-PCR, where they were found to exhibit expression trends at variance from ppe-miR165, thus indicating the cleavage mode of this miRNA on its target gene. The characterization of this important miRNA and its interaction with an equally important target gene in P. persica , further deepens our understanding of the role of ppe-miR165 in P. persica and expands the knowledge of small RNA-mediated regulation in this fruit crop.