Heterologous overexpression of CaOFP20 from pepper modulates floral development and fertility in tomato

• Heterologous overexpression of pepper CaOFP20 in tomato causes floral defects and sterility. • Impacts male and female fertility via pollen and ovule impairments. • CaOFP20 interacts with CaAG, suggesting a new floral development module. The OVATE FAMILY PROTEIN (OFP) genes encode transcription factors pivotal for plant growth and reproductive development. In pepper ( Capsicum annuum L.), previous research has primarily focused on OFP’s role in regulating fruit shape; however, the mechanism by which OFP influences floral development and fertility in pepper remains unclear. In this study, we investigated the functional role of CaOFP20 , a member of the OFP family in pepper, in regulating floral development and fertility. Results showed that the overexpression of CaOFP20 in tomato ( Solanum lycopersicum L.) resulted in evident phenotypic alterations, including aberrant floral architecture and reduced fertility. Male sterility was evident through a significant decrease in viable pollen grains and abnormalities in pollen development, while female fertility was impaired by anomalous ovule development and seed abortion. Transcriptomic analysis via RNA sequencing demonstrated that CaOFP20 overexpression significantly altered the expression of genes associated with floral morphogenesis, hormonal signaling pathways, and lipid metabolism. Notably, CaOFP20 was observed to interact with CaAG , suggesting a regulatory module governing flower development and fertility. The upregulated expression of gibberellin oxidase genes indicated that CaOFP20 modulates gibberellin homeostasis via the gibberellin catabolic pathway. These findings elucidate a regulatory mechanism by which CaOFP20 influences reproductive development in pepper, providing insights into its broader role in plant fertility.