Comprehensive analysis of WUSCHEL-related Homeobox family in Chosenia arbutifolia (Pall.) A. Skv.: Characterization, Structure, evolutionary insights, and Expression Profiles

WUSCHEL-related Homeobox (WOX) is a key transcription factor regulating plant meristems, and plays an important role in plant growth, development and stress resistance regulation. To analyze the molecular characteristics and functional potential of the CaWOX gene family in Chosenia arbutifolia (Pall.) A. Skv, genome-wide identification and bioinformatics analysis were performed in poplar in this study, and 14 CaWOX genes were identified. The 14 CaWOX genes were distributed on 11 chromosomes with 8 tandem duplications. Phylogenetic analysis divided the 14 CaWOX proteins into 4 conserved subgroups, and members in the same subgroup shared highly conserved conserved motifs and gene structures. The CaWOX family was highly evolutionarily conserved among closely related species in Salicaceae, but showed weak collinearity with Arabidopsis thaliana ; cis-elements related to meristem development, hormone response and abiotic stress were enriched in the promoter regions. Tissue development analysis revealed that CaWOX3/4/5/9/11 participated in leaf development and maintenance of physiological functions in mature leaves; CaWOX1/6/10/14 regulated root development; and CaWOX12 mediated secondary growth of stems in C. arbutifolia . This study clarified the evolutionary pattern and functional differentiation of the CaWOX family in C. arbutifolia , providing a key theoretical basis and gene resources for subsequent functional verification of this gene family, as well as growth regulation, wood property improvement and stress-resistant molecular breeding of Salicaceae trees.