The role of miR156 in rejuvenation in Arabidopsis thaliana.

Rejuvenation refers to the process enabling plants to regain physiological and molecular characteristics lost after entering the adult phase. The underlying molecular mechanism is poorly understood. Previous studies have revealed that microRNA156 (miR156) is highly accumulated at juvenile stage and maintains juvenile traits by repressing a group of SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors. Here, we found that induction of miR156 expression in adult leaves can only restore some aspects of juvenile traits, such as loss of epidermal leaf hairs on the lower side of leaves and absence of serration at the leaf edges, but is incapable of delaying flowering and promoting adventitious root production.