Recruitment of Sugar Transport and Scent Volatile Genes for Prey Attraction in the Nectar Spoon of Heliamphora tatei

Abstract

Prey attraction is an integral component of the carnivorous syndrome, yet its molecular adaptations have remained largely unexplored. Our study utilized tissue-specific transcriptomic data from the South American marsh pitcher plant, Heliamphora tatei, to explore the molecular and developmental basis of prey attraction. Carnivorous plants often present specialized structures associated with prey attraction and in Heliamphora, that function is carried out by the nectar spoon, a colorful extension of the top of the pitcher that is densely covered in nectaries. Through comparisons of gene expression in the nectar spoon with the rest of the pitcher, we identified a suite of differentially expressed genes that likely contribute to prey attraction, including enzymes involved in volatile synthesis and sugar transporters. We found that one lineage of sugar transporters, the 14a clade of SWEETs (Sugars Will Eventually Be Exported Transporters), is highly upregulated in the nectar spoon and has evolved more rapidly in Sarraceniaceae, consistent with specialization for nectar transport as part of prey attraction. Among the genes related to volatile production, we found several enzymes best known for their role in floral scent. These results suggest that, similar to prey digestion, ancient genes are repurposed for novel functions during the transition to carnivory and may facilitate the repeated convergent origins of carnivory across angiosperms.