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The shoot branching pattern is a determining phenotypic trait throughout plant development. During shoot branching, <i>BRANCHED1</i> (<i>BRC1</i>) plays a master regulator role in bud outgrowth, and its transcript levels are regulated by various exogenous and endogenous factors. <i>RhBRC1</i> (the homologous gene of <i>BRC1</i> in <i>Rosa hybrida</i>) is a main branching regulator whose posttranscriptional regulation in response to sugar was investigated through its 3′UTR. Transformed <i>Rosa</i> calluses containing a construction composed of the CaMV35S promoter, the green fluorescent protein (GFP) reporter gene, and the 3′UTR of <i>RhBRC1</i> (P35S:GFP::3′UTR<i>_RhBRC1</i>) were obtained and treated with various combinations of sugars and with sugar metabolism effectors. The results showed a major role of the 3′UTR of <i>RhBRC1</i> in response to sugars, involving glycolysis/the tricarboxylic acid cycle (TCA) and the oxidative pentose phosphate pathway (OPPP). In <i>Rosa</i> vegetative buds, sequence analysis of the <i>RhBRC1</i> 3′UTR identified six binding motifs specific to the Pumilio/FBF RNA-binding protein family (PUF) and probably involved in posttranscriptional regulation. <i>RhPUF4</i> was highly expressed in the buds of decapitated plants and in response to sugar availability in in-vitro-cultured buds. <i>RhPUF4</i> was found to be close to <i>AtPUM2</i>, which encodes an <i>Arabidopsis</i> PUF protein. In addition, sugar-dependent upregulation of <i>RhPUF4</i> was also found in <i>Rosa</i> calluses. <i>RhPUF4</i> expression was especially dependent on the OPPP, supporting its role in OPPP-dependent posttranscriptional regulation of <i>RhBRC1</i>. These findings indicate that the 3′UTR sequence could be an important target in the molecular regulatory network of <i>RhBRC1</i> and pave the way for investigating new aspects of <i>RhBRC1</i> regulation.