Complexity and innovation in carnivorous plant genomes

Carnivorous plants are a paradigm of convergent evolution, yet their genomes reveal even deeper layers of complexity. Recent work has revealed widespread polyploidy in carnivorous plants, including the decaploid East Asian pitcher plant Nepenthes gracilis and hybrid origins for the tetraploid Venus flytrap (Dionaea muscipula), the hexaploid queen sundew (Drosera regia), and the dodecaploid Cape sundew (Drosera capensis). A chromosome-scale genome for the American pitcher plant (Sarracenia purpurea) extends these insights to an independently evolved pitcher lineage. The humped bladderwort (Utricularia gibba) experienced extreme genome compaction while retaining an otherwise typical gene number, challenging assumptions about the evolution of genome size reduction. Molecular convergence is conspicuous among carnivores, from digestive enzyme recruitment to repeated amino acid substitutions under functional constraints. Drosera species further illustrate how centromere type (monocentric vs. holocentric) shapes genome architecture. These discoveries position carnivorous plants as models for studying the plasticity and adaptive landscapes of plant genomes, including tradeoffs between local and global gene duplication and intergenic DNA deletion.