The rose ZF-HD transcription factor RcHB32 regulates adventitious root development.

ZF-HD transcription factors are key regulators of plant development. The functions of lots of genes in this family have been extensively studied and reported in various model plants, but their roles in rose remain largely unclear. In this comprehensive study, seven ZF-HD genes were identified in the rose (Rosa chinensis) genome. RT-qPCR analysis revealed that nearly all of these genes were highly expressed in flowers. In contrast, RcHB32 displayed a distinct expression pattern, with high transcript levels predominantly in roots. Functional characterization suggested that RcHB32 plays a positive role in adventitious root development in rose, with its silencing significantly reducing both adventitious root number and length. Moreover, we found that RcLBD29 acts as a direct downstream target of RcHB32, and RcHB32 enhances RcLBD29 transcription by binding to its promoter. Functional characterization of RcLBD29 showed that it also positively regulates adventitious root development. Thus, these results indicate that the RcHB32-RcLBD29 module contributes to adventitious root development in rose. These findings provide a basis for understanding the molecular regulation of adventitious root development in rose.