Comprehensive analysis and identification of the WOX gene family in Schima superba and the key gene SsuWOX1 for enhancing callus regeneration capacity.

This study conducted a comprehensive analysis of the SsuWOX gene family in Schima superba, elucidating its role in plant growth and stress response mechanisms. The genome contains 15 WOX genes primarily encoding nuclear proteins unevenly distributed across 18 chromosomes. Phylogenetic classification grouped these genes into three distinct subfamilies, with members in each subfamily showing conserved gene structures. Interaction network analysis and cis-regulatory element characterization revealed that SsuWOX gene expression is influenced by hormones and various abiotic stresses. Tissue-specific expression profiles showed six genes exhibiting spatial specificity with significant expression level variations across developmental stages. Notably, SsuWOX1 overexpression in callus tissue significantly elevated CLAVATA3 (CLV3) expression levels. CLV3, a crucial small peptide signaling molecule, primarily regulates stem cell maintenance and differentiation in the shoot apical meristem (SAM). Transgenic callus cells displayed bud-like cell characteristics, including increased cell density and organized spatial arrangement. These findings establish a foundation for functional characterization of SsuWOX1 and provide insights into its regulatory mechanisms in plant development.