Electrophysiological and pharmacological characteristics of the Slowpoke channel in Brown Rice Planthopper, Nilaparvata lugens (Stål)

Slowpoke (Slo) channels are vital components of the nervous system, making them promising targets for developing neuromodulatory pesticides. However, there is limited research on the physiological roles and inhibitors of Slo channels in agricultural pests like the brown planthopper ( Nilaparvata lugens ). This study investigates the composition and essential functions of Slo channels in N. lugens through gene sequence analysis, patch-clamp electrophysiology, and inhibitor bioassays, offering valuable information for pest control approaches targeting these channels. The full coding sequence (3513 base pairs) of the N. lugens Slo gene was cloned, and five alternative splicing regions labeled A, C, E, G, and I were identified. Whole-cell patch-clamp experiments showed that the NlSlo channel exhibits typical features of calcium-activated large-conductance potassium channels, with a half-activation voltage (V 1/2 ) of 18.04 ± 0.94 mV. Removing the E region notably enhanced the channel's response to depolarization, while deleting the I region significantly reduced channel current. Among the tested inhibitors, iberiotoxin produced the strongest inhibition of the NlSlo channel at 66.21 % when applied at 10 μM, whereas plant-derived compounds inhibited the channel by 24.2 % to 48.95 % at the same concentration. In comparison, five pesticides—transfluthrin, flonicamid, tebufenozide, acynonapyr, and cypermethrin—showed inhibition rates ranging from 30.11 % to 42.74 % at 100 μM. Notably, injections of the specific inhibitor iberiotoxin significantly decreased both survival and movement abilities in N. lugens . This research highlights the critical role of Slo channel inhibition in affecting the survival and locomotion of N. lugens , providing new perspectives for developing pest management strategies targeting this species.