Genome architecture partitions developmental stability and ecological specialization in the carnivorous pitcher plant Sarracenia purpurea

The repeated evolution of complex traits raises the question of how genomes generate ecological novelty while preserving developmental stability. Carnivorous pitcher plants modify the leaf into a prey-capturing organ, yet the genomic basis of their convergent evolution across flowering plants remains unresolved. We present a chromosome-scale genome assembly for the purple pitcher plant, Sarracenia purpurea, and analyze it alongside eight angiosperms spanning Ericales and independent carnivorous lineages. The genome retains extensive syntenic blocks from ancient polyploidy, organized into a mosaic of dominant and recessive subgenomic segments. Dominant regions preferentially retain dosage-sensitive regulators including AGO1, BRX, GATA11, ETC1, and RCD1, defining a conserved developmental scaffold associated with leaf morphogenesis. In contrast, tandem duplications concentrate in structurally dynamic regions and are enriched for detoxification, redox buffering, microbial-interaction, and cell-wall processes required to maintain digestive chemistry and trap physiology. Comparative analyses across four carnivorous taxa reveal convergent recruitment of oxidative, transport, and microbial-interaction pathways, with transcriptomic data confirming their activation in pitcher tissue. Pitcher evolution thus reflects genomic partitioning between conserved developmental control and rapidly evolving ecological effectors.