Identification of an arthropod molecular target for plant-derived natural repellents

Arthropods maintain ecosystem balance, while also contribute to disease spreading. Plant-derived natural repellents represent an ecological way of pest control, but their direct molecular targets in arthropods remain to be further elucidated. Occupying a critical phylogenetic niche in arthropod evolution, scorpions retain an ancestral genetic profile. Here, using a behavior-guided screening of the Mesobuthus martensii genome, we identified a scorpion transient receptor potential (sTRP1) channel that senses Cymbopogon-derived natural repellents, while insensitive to the synthetic chemical pesticide DEET. Scrutinizing orthologs of sTRP1 in Drosophila melanogaster, we further demonstrated dTRPϒ ion channel also as a chemosensory receptor of natural repellents to mediate avoidance behavior. This study sheds light on arthropod molecular targets of natural repellents, exemplifying the arthropod-plant adaptation. It should also help the rational design of insect control strategy and conserve biodiversity.

Methods
Electrophysiological data were mainly collected from traditional patch-clamp recordings and Ca2+ imaging. All behavioral experiments with scorpions or flies were conducted in a double-blind manner.