Find in Library

The WUSCHEL-related homeobox (WOX) transcription factor plays a vital role in stem cell maintenance and organ morphogenesis, which are essential processes for plant growth and development. <i>Dendrobium chrysotoxum</i>, <i>D. huoshanense</i>, and <i>D. nobile</i> are valued for their ornamental and medicinal properties. However, the specific functions of the WOX gene family in <i>Dendrobium</i> species are not well understood. In our study, a total of 30 WOX genes were present in the genomes of the three <i>Dendrobium</i> species (nine DchWOXs, 11 DhuWOXs, and ten DnoWOXs). These 30 WOXs were clustered into ancient clades, intermediate clades, and WUS/modern clades. All 30 WOXs contained a conserved homeodomain, and the conserved motifs and gene structures were similar among WOXs belonging to the same branch. <i>D. chrysotoxum</i> and <i>D. huoshanense</i> had one pair of fragment duplication genes and one pair of tandem duplication genes, respectively; <i>D. nobile</i> had two pairs of fragment duplication genes. The <i>cis</i>-acting regulatory elements (CREs) in the WOX promoter region were mainly enriched in the light response, stress response, and plant growth and development regulation. The expression pattern and RT-qPCR analysis revealed that the WOXs were involved in regulating the floral organ development of <i>D. chrysotoxum</i>. Among them, the high expression of <i>DchWOX3</i> suggests that it might be involved in controlling lip development, whereas <i>DchWOX5</i> might be involved in controlling ovary development. In conclusion, this work lays the groundwork for an in-depth investigation into the functions of WOX genes and their regulatory role in <i>Dendrobium</i> species’ floral organ development.