Multiple Antennal Sensory Membrane Neuron Protein Genes Mediate Rice Plant Host Location in the White-Backed Planthopper

While the sensory neuron membrane protein (SNMP) family has been linked to sex pheromone detection, roles in other olfactory-associated and nonolfactory functions have not been as well-defined. In this study, four SNMP genes were identified for the white-backed planthopper (Sogatella furcifera; WBPH), a major pest of rice plants. Tissue-specific transcriptomic data indicated that all four SfurSNMPs are not only expressed in the antennae to varying levels but also observed in several non-olfactory tissues. RNA interference knockdown reduced expression levels of all four transcripts in WBPH nymphs. SfurSNMP knockdown delayed the movement of nymphs toward a rice plant source with most nymphs congregating in a no response zone rather than moving toward the host plant. The expression of diverse signaling pathway genes was impacted following the knockdown of the different SfurSNMPs, suggesting that SNMP function extends beyond odorant detection, in addition to providing evidence for SNMP function in nonsex pheromone-related WBPH olfaction.