Genome-wide analysis of the WOX gene family and identification of candidate genes for adventitious shoot regeneration in peanut

The WUSCHEL-related homeobox (WOX) transcription factor family plays central roles in maintaining stem cell homeostasis and regulating organogenesis in plants. Genetic transformation of peanut (<italic>Arachis hypogaea</italic> L.), a globally important oilseed crop, remains severely limited by low regeneration efficiency. Here, we conducted a genome-wide identification and characterization of <italic>WOX</italic> genes in the peanut cultivar ‘Fuhuasheng’ to pinpoint candidates potentially involved in organ regeneration and to provide a basis for overcoming regeneration-related constraints in peanut transformation. We identified 20 <italic>WOX</italic> genes and systematically analyzed their phylogenetic relationships, conserved domains, collinearity, and promoter features, and then profiled their expression across tissues and during adventitious shoot regeneration using transcriptome data. Phylogenetic analysis clustered the <italic>AhWOX</italic> genes into three clades (ancient, intermediate, and WUS). All AhWOX proteins contained a conserved homeodomain (HD), and several WUS-clade members also carried the WUS-box and EAR motifs. Collinearity analysis indicated that <italic>AhWOX7</italic>, <italic>AhWOX12</italic>, and <italic>AhWOX14</italic> are orthologs of <italic>Arabidopsis thaliana WUS</italic> and <italic>WOX5</italic> and of the soybean regeneration-related gene <italic>GmWOX18</italic>, respectively. However, these orthologs showed only low expression, whereas the ancient-clade genes <italic>AhWOX13</italic> and<italic> AhWOX20 </italic>were consistently highly expressed across all stages of adventitious shoot regeneration. Promoter analysis revealed enrichment of <italic>cis</italic>-elements associated with meristem activity, and phylogenetic evidence suggested that <italic>AhWOX13</italic> and <italic>AhWOX20</italic> are orthologous to <italic>AtWOX14</italic>, a reported positive regulator of shoot regeneration. Collectively, our results highlight <italic>AhWOX13</italic> and <italic>AhWOX20 </italic>as promising candidates for improving regeneration capacity in peanut, providing a framework to enhance peanut transformation and accelerate functional genomics and trait engineering in oilseed crops.