OsmiR164?targeted<i>OsNAM</i>, a boundary gene, plays important roles in rice leaf and panicle development

The CUP-SHAPED COTYLEDON (CUC) genes (CUC1, CUC2 and CUC3) regulate organ boundary formation in Arabidopsis. However, the functions of their homologous rice (Oryza sativa) are still unknown. Here, we have identified an orthologous gene CUC1 rice, named OsNAM. Subcellular localization yeast two-hybrid assay results suggested that OsNAM encodes a conserved nuclear NAC (NAM/ATAF1/CUC2) protein with transcriptional activator. null mutant osnam-1 presented fused leaf structure, small panicles, reduced branches aberrant floral identities when compared those wild type. Beta-glucuronidase staining GFP reporter lines indicated was expressed young tissues its enrichment expression regulated by OsmiR164. Loss-of-function mutants for OsCUC3 resulted no obvious defects throughout development. osnam oscuc3 double mutant, however, severe fusion first two leaves, while single showed similar phenotype from seventh leaf. These act redundantly specification during post-embryonic Overall, describe biological development characteristics This work reveals important role CUC rice.