Block of Kir channels by flonicamid disrupts salivary and renal excretion of insect pests

Chemical inhibition of Kir channels reduces salivary secretions and phloem feeding of the cotton aphid, Aphis gossypii (Glover)

“…Kir channel mRNA is highly expressed in the salivary gland of the brown planthopper ( Nilaparvata lugens ) and the common fruit fly ( Drosophila melanogaster L.) and these channels have been implicated in regulating the secretory activity of the salivary gland and subsequent feeding . For instance, chemical inhibition of Kir channels and salivary gland specific knockdown of Kir channel mRNA in D. melanogaster reduced the volume of sucrose ingestion and, similarly, chemical inhibition of Kir1 significantly reduced the salivary secretions and feeding behavior of N. lugens . Our data with A. gossypii support these previous studies by demonstrating that VU041 and VU590 are capable of reducing salivary secretions during feeding (Fig.…”

“…25,35,50 For instance, chemical inhibition of Kir channels and salivary gland specific knockdown of Kir channel mRNA in D. melanogaster reduced the volume of sucrose ingestion 25 and, similarly, chemical inhibition of Kir1 significantly reduced the salivary secretions and feeding behavior of N. lugens. 35,51 Our data with A. gossypii support these previous studies by demonstrating that VU041 and VU590 are capable of reducing salivary secretions during feeding (Fig. 2(E)) and contact exposure to VU041 prevented phloem feeding in EPG studies (Fig.…”

“…Beyond acute lethality, Kir channels represent a putative molecular target to induce toxicity through antifeedant properties. Kir channel mRNA is highly expressed in the salivary gland of the brown planthopper ( Nilaparvata lugens ) and the common fruit fly ( Drosophila melanogaster L.) and these channels have been implicated in regulating the secretory activity of the salivary gland and subsequent feeding . For instance, chemical inhibition of Kir channels and salivary gland specific knockdown of Kir channel mRNA in D. melanogaster reduced the volume of sucrose ingestion and, similarly, chemical inhibition of Kir1 significantly reduced the salivary secretions and feeding behavior of N. lugens .…”

“…Similarly, several recent lines of genetic and pharmacological evidence suggest Kir channels play important physiological roles in exocrine systems of dipteran insects as well. For instance, genetic depletion or pharmacological inhibition of Kir channels have been shown to reduce the fluid and ion secretion of dipteran Malpighian tubules and previous work has indicated Kir channels are critical for the salivary gland function and feeding of arthropods pests . The development of insect Kir channel pharmacology has enabled researchers to begin to characterize the physiological role of these channels in various arthropod tissue systems as well as determine the toxicological relevance to pest species.…”

“…For instance, genetic depletion or pharmacological inhibition of Kir channels have been shown to reduce the fluid and ion secretion of dipteran Malpighian tubules 24,[31][32][33][34] and previous work has indicated Kir channels are critical for the salivary gland function and feeding of arthropods pests. 25,26,35 The development of insect Kir channel pharmacology 23,34,36,37 has enabled researchers to begin to characterize the physiological role of these channels in various arthropod tissue systems as well as determine the toxicological relevance to pest species. For instance, the insect-specific Kir inhibitor termed VU041 was shown to inhibit A. glycines (soybean aphid) Kir1 and Kir2 currents in electrophysiological studies and topical application resulted in acute mortality, 38 indicating Kir channels are important for aphid survivorship.…”