Three <i>Orobanche</i> genomes reveal distinct molecular repertoires in species with different host ranges

Parasitic plants in the genus Orobanche display varying levels of host specificity, however, the molecular features determining host range are not fully understood. We sequenced the genomes of three Orobanche species with different host ranges: O. minor (generalist), O. gracilis (Fabaceae-specific), and Orobanche hederae (ivy-specific). Comparative analysis revealed considerable genome size variation but consistent holoparasitic gene loss patterns. While synteny analysis revealed strong collinearity between O. gracilis, O. hederae, and O. minor, we found distinct molecular repertoires among species. O. gracilis showed expanded protein-degrading and carbohydrate-active enzyme families, while putative strigolactone receptor (KAI2d) numbers varied from five in specialists to eleven in the generalist O. minor, suggesting diverse molecular strategies across different host ranges.