ptr-MIR169 is a posttranscriptional repressor of PtrHAP2 during vegetative bud dormancy period of aspen (Populus tremuloides) trees

► We show a novel microRNA-mediated mechanism for control of bud dormancy in trees. ► ptr-MIR169a and PtrHAP2-5 gene showed inverse expression during dormancy period. ► The PtrHAP2-5 decline in abundance correlated with high ptr-MIR169a levels. ► PtrHAP2-5 cleavage occurred at the miR169 site during PtrHAP2-5 transcript decline. ► Our results show that miR169 attenuates PtrHAP2-5 transcript during dormancy.