PhD candidate Louisiana State University Baton Rouge, Louisiana
Vector control is becoming increasingly difficult due to the evolution of resistance to conventional insecticides across arthropod taxa, which highlights the need for development of insecticides with novel mode of action. Arthropod feeding is the primary concern because it is the event that facilitates pathogen transmission or physical damage to humans or agricultural systems, respectively. Inwardly rectifying potassium (Kir) channels are known to be critical for epithelial cell function in vertebrates and invertebrates, yet little is known regarding their function in arthropod salivary glands. Thus, we aimed to characterize the physiological role and toxicological relevance of Kir channels in arthropod salivary gland in an effort to validate and develop novel antifeedants. Our proof-of-concept study showed that chemical and genetic depletion of salivary gland specificKir channels in Drosophila significantly reduced sucrose consumption in adult flies, suggesting the critical roles of Kir channels in arthropod feeding. This proof-of-concept study justified assessing the toxicological relevance of Kir channels in the salivary gland of medical and agricultural pests. Interestingly, we found activators of ATP-sensitive Kir channels significantly reduced fluid secretion and blood ingestion from ticks and mosquitoes, suggesting that ATP-sensitive Kir channels are closely involved in arthropod blood feeding. Kir modulators were also tested on the cotton aphid Aphis gossypii. EPG data illustrated that aphids had zero phloem ingestion and showed mortality after 72h when feeding on leaves treated with classic Kir blockers. Taken together, our data suggest that salivary gland Kir channels represent promising targets for development of novel antifeedant insecticides.
