Abstract
U-box proteins are a class of E3 ubiquitin ligases structurally similar to RING finger proteins but independent of metal ion coordination, and they play important regulatory roles in various biological processes such as cellular stress responses and protein homeostasis. However, research on U-box genes in banana (Musa acuminata, Cavendish, ‘DH-PaHang’) remains limited. In this study, we identified 90 MaPUBs based on the genome sequence of Musa acuminata. Phylogenetic analysis revealed that PUB genes from Musa acuminata, Arabidopsis thaliana, Oryza sativa and Mangifera indica could be categorized into four distinct groups (I–IV). Additionally, the examination of conserved motifs and gene architectures further validated the phylogenetic tree, offering compelling support for the inferred evolutionary relationships. The MaPUBs are distributed across all 11 chromosomes at varying densities. The analysis of cis-acting elements indicates that MaPUBs are potentially involved in diverse biological processes, reflecting their functional versatility in modulating gene expression and cellular functions Based on transcriptomic data showing distinct expression patterns of MaPUB genes at five time points under drought stress, we randomly selected 12 genes for qRT-PCR analysis to identify drought-tolerance candidates. Based on transcriptomic analysis and expression profiling validation, we selected the MaPUB79 gene, which exhibited high expression levels across all three time periods and was consistent with the RNA-Seq data, for further functional validation to elucidate its role in the drought response mechanism.Using virus-induced gene silencing (VIGS) to suppress MaPUB79 expression led to a marked decline in the drought resistance of Musa acuminata. In summary, this study performed a systematic genome-wide characterization of the PUB gene family in Musa acuminata, offering key insights into PUB-mediated drought resistance mechanisms. These findings provide a theoretical basis for future investigations into the functional roles and underlying mechanisms of the crop’s response to drought stress. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12870-025-07592-6.