BackgroundBranching is a plastic character that affects plant architecture and spatial structure. The trait is controlled by a variety of plant hormones through coordination with environmental signals. Plant AT-rich sequence and zinc-binding protein (PLATZ) is a transcription factor that plays an important role in plant growth and development. However, systematic research on the role of the PLATZ family in apple branching has not been conducted previously.ResultsIn this study, a total of 17PLATZgenes were identified and characterized from the apple genome. The 83 PLATZ proteins from apple, tomato,Arabidopsis, rice, and maize were classified into three groups based on the topological structure of the phylogenetic tree. The phylogenetic relationships, conserved motifs, gene structure, regulatorycis-acting elements, andmicroRNAsof theMdPLATZfamily members were predicted. Expression analysis revealed thatMdPLATZgenes exhibited distinct expression patterns in different tissues. The expression patterns of theMdPLATZgenes were systematically investigated in response to treatments that impact apple branching [thidazuron (TDZ) and decapitation]. The expression ofMdPLATZ1, 6, 7, 8, 9, 15, and 16 was regulated during axillary bud outgrowth based on RNA-sequencing data obtained from apple axillary buds treated by decapitation or exogenous TDZ application. Quantitative real-time PCR analysis showed thatMdPLATZ6was strongly downregulated in response to the TDZ and decapitation treatments, however,MdPLATZ15was significantly upregulated in response to TDZ, but exhibited little response to decapitation. Furthermore, the co-expression network showed that PLATZ might be involved in shoot branching by regulating branching-related genes or mediating cytokinin or auxin pathway.ConclusionThe results provide valuable information for further functional investigation ofMdPLATZgenes in the control of axillary bud outgrowth in apple.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12864-023-09399-x.