Overexpression of Sly-miR164a in tomato decreases expression of NAC and delays pre- and postharvest ripening of fruit

Fruit ripening of tomato is regulated by NAC (NAM, ATAF1/2, and CUC2) domain proteins such as NOR-like1, SlNAC1, and SlNAC4. Acts as an up-stream regulator of NAC genes, the high abundance of miR164 might eliminate the impact of NAC on the ripening of fleshy fruit. In the present study, the STTM-miR164a (silencing miR164a by short tandem target mimic) and OE-miR164a (overexpression of miR164a) tomato lines were generated. Compared with those of silenced miR164a, overexpression of miR164a decreased ethylene production and lycopene accumulation, and delayed pre-and postharvest ripening of fruit. The expression analysis of target genes of miR164a revealed that the NAM3 (Solyc06g069710), GOB (Solyc07g062840) and NAC1 (Solyc07g066330) were involved in regulating fruit ripening.