MicroRNA miR396 and RDR6 synergistically regulate leaf development

► A 35S:miR396 enhancer screen identified mutations in AS2 and RDR6. ► Defects caused by miR396 overexpression are more severe in rdr6 than as2 backgrounds. ► Overexpression of miR396 caused needle-like organs in rdr6, sgs3 and ago7 mutants. ► High levels of miR396 can per se generate needle-like leaf structures. ► High levels of TCP4, which activates miR396, can also generate lotus-like organs.